{"id":35,"date":"2026-03-14T22:23:15","date_gmt":"2026-03-14T14:23:15","guid":{"rendered":"http:\/\/47.118.30.30\/?p=35"},"modified":"2026-03-15T11:40:56","modified_gmt":"2026-03-15T03:40:56","slug":"java%e7%ac%94%e8%ae%b0","status":"publish","type":"post","link":"https:\/\/arknight.wiki\/index.php\/2026\/03\/14\/java%e7%ac%94%e8%ae%b0\/","title":{"rendered":"java\u7b14\u8bb0"},"content":{"rendered":"<h1>java\u57fa\u7840<\/h1>\n<h2><\/h2>\n<h2>\u4e00\u4e9b\u57fa\u672c\u7684\uff1a<\/h2>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01\uff1ajava\u4e2d\u6587\u4ef6\u540d\u8981\u4e0e\u7c7b\u540d\u4e00\u81f4<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a02\uff1a\u7f16\u8bd1\u6587\u4ef6\uff1aJava\u6587\u4ef6\u8fd0\u884c\u524d\u9700\u8981\u5148\u7f16\u8bd1\u4e3a class \u5b57\u8282\u7801\u6587\u4ef6\uff0c\u5982\uff1a<\/p>\n<pre><code>$ javac HelloWorld.java\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/\u4f7f\u7528javac\u6307\u4ee4\u7f16\u8bd1\uff0c\u8fd0\u884cjavac\u547d\u4ee4\u540e\uff0c\u5982\u679c\u6210\u529f\u7f16\u8bd1\u6ca1\u6709\u9519\u8bef\u7684\u8bdd\uff0c\u4f1a\u51fa\u73b0\u4e00\u4e2a HelloWorld.class \u7684\u6587\u4ef6<\/code><\/pre>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a03\uff1a\u8fd0\u884c\u6587\u4ef6\uff1a\u7528java\u6307\u4ee4\uff0cjava\u540e\u9762\u8ddf\u7684\u662f\u7c7b\u540d\u800c\u4e0d\u662f\u6587\u4ef6\u540d\uff0c\u5982\uff1a<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/p>\n<pre><code>$ java HelloWorld\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/\u8fd0\u884c\u7f16\u8bd1\u597d\u7684class\u6587\u4ef6<\/code><\/pre>\n<h2>\u57fa\u7840\u8bed\u6cd5\uff1a<\/h2>\n<p>\u4e00\u4e2a\u7b80\u5355\u7a0b\u5e8f\uff1a<\/p>\n<pre><code>public class HelloWorld {\n    \/* \u7b2c\u4e00\u4e2aJava\u7a0b\u5e8f\n     * \u5b83\u5c06\u8f93\u51fa\u5b57\u7b26\u4e32 Hello World\n     *\/\n    public static void main(String[] args) {\n        System.out.println(\"Hello World\"); \/\/ \u8f93\u51fa Hello World\n    }\n}\n<\/code><\/pre>\n<p>1\uff1ajava\u4e2d\u5bf9\u4e8e\u65b9\u6cd5\u7684\u5b9a\u4e49\uff1a<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u4f8b\uff1a<\/p>\n<pre><code>    public static void main(String[] args)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><\/pre>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u89c4\u5219\uff1a\u7c7b\u4f3cc\u8bed\u8a00\u5b9a\u4e49\u51fd\u6570<\/p>\n<p><img decoding=\"async\" title=\"\" src=\"file:\/\/\/C:\/Users\/inex\/Pictures\/Typedown\/09bea80e-c30b-4f20-9032-c30b6d3ace9f.png\" alt=\"09bea80e-c30b-4f20-9032-c30b6d3ace9f\" style=\"zoom:50%;\"><\/p>\n<p>2\uff1a<strong>\u5927\u5c0f\u5199\u654f\u611f<\/strong>\uff1aJava \u662f\u5927\u5c0f\u5199\u654f\u611f\u7684\uff0c\u8fd9\u5c31\u610f\u5473\u7740\u6807\u8bc6\u7b26 Hello \u4e0e hello \u662f\u4e0d\u540c\u7684\u3002<\/p>\n<p>3\uff1a<strong>\u7c7b\u540d<\/strong>\uff1a\u5bf9\u4e8e\u6240\u6709\u7684\u7c7b\u6765\u8bf4\uff0c\u7c7b\u540d\u7684\u9996\u5b57\u6bcd\u5e94\u8be5\u5927\u5199\u3002\u5982\u679c\u7c7b\u540d\u7531\u82e5\u5e72\u5355\u8bcd\u7ec4\u6210\uff0c\u90a3\u4e48\u6bcf\u4e2a\u5355\u8bcd\u7684\u9996\u5b57\u6bcd\u5e94\u8be5\u5927\u5199\uff0c\u4f8b\u5982\u00a0<strong>MyFirstJavaClass<\/strong>\u00a0\u3002<\/p>\n<p>4\uff1a<strong>\u65b9\u6cd5\u540d<\/strong>\uff1a\u6240\u6709\u7684\u65b9\u6cd5\u540d\u90fd\u5e94\u8be5\u4ee5\u5c0f\u5199\u5b57\u6bcd\u5f00\u5934\u3002\u5982\u679c\u65b9\u6cd5\u540d\u542b\u6709\u82e5\u5e72\u5355\u8bcd\uff0c\u5219\u540e\u9762\u7684\u6bcf\u4e2a\u5355\u8bcd\u9996\u5b57\u6bcd\u5927\u5199\u3002<\/p>\n<p>5\uff1a<strong>\u6e90\u6587\u4ef6\u540d<\/strong>\uff1a\u6e90\u6587\u4ef6\u540d\u5fc5\u987b\u548c\u7c7b\u540d\u76f8\u540c\u3002\u5f53\u4fdd\u5b58\u6587\u4ef6\u7684\u65f6\u5019\uff0c\u4f60\u5e94\u8be5\u4f7f\u7528\u7c7b\u540d\u4f5c\u4e3a\u6587\u4ef6\u540d\u4fdd\u5b58\uff08\u5207\u8bb0 Java \u662f\u5927\u5c0f\u5199\u654f\u611f\u7684\uff09\uff0c\u6587\u4ef6\u540d\u7684\u540e\u7f00\u4e3a\u00a0<strong>.java<\/strong>\u3002\uff08\u5982\u679c\u6587\u4ef6\u540d\u548c\u7c7b\u540d\u4e0d\u76f8\u540c\u5219\u4f1a\u5bfc\u81f4\u7f16\u8bd1\u9519\u8bef\uff09\u3002<\/p>\n<p>6\uff1a<strong>\u4e3b\u65b9\u6cd5\u5165\u53e3<\/strong>\uff1a\u6240\u6709\u7684 Java \u7a0b\u5e8f\u7531\u00a0<strong>public static void main(String[] args)<\/strong>\u00a0\u65b9\u6cd5\u5f00\u59cb\u6267\u884c\u3002<br \/>\nJava \u6807\u8bc6\u7b26\uff1a<\/p>\n<hr \/>\n<p>Java \u6240\u6709\u7684\u7ec4\u6210\u90e8\u5206\u90fd\u9700\u8981\u540d\u5b57\u3002\u7c7b\u540d\u3001\u53d8\u91cf\u540d\u4ee5\u53ca\u65b9\u6cd5\u540d\u90fd\u88ab\u79f0\u4e3a\u6807\u8bc6\u7b26\u3002<\/p>\n<p>\u5173\u4e8e Java \u6807\u8bc6\u7b26\uff0c\u6709\u4ee5\u4e0b\u51e0\u70b9\u9700\u8981\u6ce8\u610f\uff1a<\/p>\n<ul>\n<li>\u6240\u6709\u7684\u6807\u8bc6\u7b26\u90fd\u5e94\u8be5\u4ee5\u5b57\u6bcd\uff08A-Z \u6216\u8005 a-z\uff09,\u7f8e\u5143\u7b26\uff08$\uff09\u3001\u6216\u8005\u4e0b\u5212\u7ebf\uff08_\uff09\u5f00\u59cb<\/li>\n<li>\u9996\u5b57\u7b26\u4e4b\u540e\u53ef\u4ee5\u662f\u5b57\u6bcd\uff08A-Z \u6216\u8005 a-z\uff09,\u7f8e\u5143\u7b26\uff08$\uff09\u3001\u4e0b\u5212\u7ebf\uff08_\uff09\u6216\u6570\u5b57\u7684\u4efb\u4f55\u5b57\u7b26\u7ec4\u5408<\/li>\n<li>\u5173\u952e\u5b57\u4e0d\u80fd\u7528\u4f5c\u6807\u8bc6\u7b26<\/li>\n<li>\u6807\u8bc6\u7b26\u662f\u5927\u5c0f\u5199\u654f\u611f\u7684<\/li>\n<li>\u5408\u6cd5\u6807\u8bc6\u7b26\u4e3e\u4f8b\uff1aage\u3001$salary\u3001_value\u3001__1_value<\/li>\n<li>\u975e\u6cd5\u6807\u8bc6\u7b26\u4e3e\u4f8b\uff1a123abc\u3001-salary<\/li>\n<li>\n<\/li>\n<\/ul>\n<h2>Java\u4fee\u9970\u7b26<\/h2>\n<p>\u50cf\u5176\u4ed6\u8bed\u8a00\u4e00\u6837\uff0cJava\u53ef\u4ee5\u4f7f\u7528\u4fee\u9970\u7b26\u6765\u4fee\u9970\u7c7b\u4e2d\u65b9\u6cd5\u548c\u5c5e\u6027\u3002\u4e3b\u8981\u6709\u4e24\u7c7b\u4fee\u9970\u7b26\uff1a<\/p>\n<ul>\n<li>\u8bbf\u95ee\u63a7\u5236\u4fee\u9970\u7b26 : default, public , protected, private<\/li>\n<li>\u975e\u8bbf\u95ee\u63a7\u5236\u4fee\u9970\u7b26 : final, abstract, static, synchronized<\/li>\n<\/ul>\n<p>\u5728\u540e\u9762\u7684\u7ae0\u8282\u4e2d\u6211\u4eec\u4f1a\u6df1\u5165\u8ba8\u8bba Java \u4fee\u9970\u7b26\u3002<br \/>\nJava \u53d8\u91cf<\/p>\n<hr \/>\n<p>Java \u4e2d\u4e3b\u8981\u6709\u5982\u4e0b\u51e0\u79cd\u7c7b\u578b\u7684\u53d8\u91cf  <\/p>\n<ul>\n<li>\u5c40\u90e8\u53d8\u91cf<\/li>\n<li>\u7c7b\u53d8\u91cf\uff08\u9759\u6001\u53d8\u91cf\uff09<\/li>\n<li>\u6210\u5458\u53d8\u91cf\uff08\u975e\u9759\u6001\u53d8\u91cf\uff09<\/li>\n<\/ul>\n<h2>Java \u6570\u7ec4<\/h2>\n<p>\u6570\u7ec4\u662f\u50a8\u5b58\u5728\u5806\u4e0a\u7684\u5bf9\u8c61\uff0c\u53ef\u4ee5\u4fdd\u5b58\u591a\u4e2a\u540c\u7c7b\u578b\u53d8\u91cf\u3002\u5728\u540e\u9762\u7684\u7ae0\u8282\u4e2d\uff0c\u6211\u4eec\u5c06\u4f1a\u5b66\u5230\u5982\u4f55\u58f0\u660e\u3001\u6784\u9020\u4ee5\u53ca\u521d\u59cb\u5316\u4e00\u4e2a\u6570\u7ec4\u3002<br \/>\nJava \u679a\u4e3e<\/p>\n<hr \/>\n<p>Java 5.0\u5f15\u5165\u4e86\u679a\u4e3e\uff0c\u679a\u4e3e\u9650\u5236\u53d8\u91cf\u53ea\u80fd\u662f\u9884\u5148\u8bbe\u5b9a\u597d\u7684\u503c\u3002\u4f7f\u7528\u679a\u4e3e\u53ef\u4ee5\u51cf\u5c11\u4ee3\u7801\u4e2d\u7684 bug\u3002<\/p>\n<p>\u4f8b\u5982\uff0c\u6211\u4eec\u4e3a\u679c\u6c41\u5e97\u8bbe\u8ba1\u4e00\u4e2a\u7a0b\u5e8f\uff0c\u5b83\u5c06\u9650\u5236\u679c\u6c41\u4e3a\u5c0f\u676f\u3001\u4e2d\u676f\u3001\u5927\u676f\u3002\u8fd9\u5c31\u610f\u5473\u7740\u5b83\u4e0d\u5141\u8bb8\u987e\u5ba2\u70b9\u9664\u4e86\u8fd9\u4e09\u79cd\u5c3a\u5bf8\u5916\u7684\u679c\u6c41\u3002<\/p>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>class FreshJuice {\n   enum FreshJuiceSize{ SMALL, MEDIUM , LARGE }\n   FreshJuiceSize size;\n}\n\npublic class FreshJuiceTest {\n   public static void main(String[] args){\n      FreshJuice juice = new FreshJuice();\n      juice.size = FreshJuice.FreshJuiceSize.MEDIUM  ;\n   }\n}<\/code><\/pre>\n<h2>Java \u5173\u952e\u5b57<\/h2>\n<p>\u4e0b\u9762\u5217\u51fa\u4e86 Java \u5173\u952e\u5b57\u3002\u8fd9\u4e9b\u4fdd\u7559\u5b57\u4e0d\u80fd\u7528\u4e8e\u5e38\u91cf\u3001\u53d8\u91cf\u3001\u548c\u4efb\u4f55\u6807\u8bc6\u7b26\u7684\u540d\u79f0\u3002<\/p>\n<table>\n<thead>\n<tr>\n<th>\u7c7b\u522b\/\u5173\u952e\u5b57<\/th>\n<th>\u8bf4\u660e<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>\u8bbf\u95ee\u63a7\u5236<\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>private<\/td>\n<td>\u79c1\u6709\u7684<\/td>\n<\/tr>\n<tr>\n<td>protected<\/td>\n<td>\u53d7\u4fdd\u62a4\u7684<\/td>\n<\/tr>\n<tr>\n<td>public<\/td>\n<td>\u516c\u5171\u7684<\/td>\n<\/tr>\n<tr>\n<td>default<\/td>\n<td>\u9ed8\u8ba4<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>\u7c7b\u3001\u65b9\u6cd5\u548c\u53d8\u91cf\u4fee\u9970\u7b26<\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>abstract<\/td>\n<td>\u58f0\u660e\u62bd\u8c61<\/td>\n<\/tr>\n<tr>\n<td>class<\/td>\n<td>\u7c7b<\/td>\n<\/tr>\n<tr>\n<td>extends<\/td>\n<td>\u6269\u5145\u3001\u7ee7\u627f<\/td>\n<\/tr>\n<tr>\n<td>final<\/td>\n<td>\u6700\u7ec8\u503c\u3001\u4e0d\u53ef\u6539\u53d8\u7684<\/td>\n<\/tr>\n<tr>\n<td>implements<\/td>\n<td>\u5b9e\u73b0\uff08\u63a5\u53e3\uff09<\/td>\n<\/tr>\n<tr>\n<td>interface<\/td>\n<td>\u63a5\u53e3<\/td>\n<\/tr>\n<tr>\n<td>native<\/td>\n<td>\u672c\u5730\u3001\u539f\u751f\u65b9\u6cd5\uff08\u975e Java \u5b9e\u73b0\uff09<\/td>\n<\/tr>\n<tr>\n<td>new<\/td>\n<td>\u521b\u5efa<\/td>\n<\/tr>\n<tr>\n<td>static<\/td>\n<td>\u9759\u6001<\/td>\n<\/tr>\n<tr>\n<td>strictfp<\/td>\n<td>\u4e25\u683c\u6d6e\u70b9\u3001\u7cbe\u51c6\u6d6e\u70b9<\/td>\n<\/tr>\n<tr>\n<td>synchronized<\/td>\n<td>\u7ebf\u7a0b\u3001\u540c\u6b65<\/td>\n<\/tr>\n<tr>\n<td>transient<\/td>\n<td>\u77ed\u6682<\/td>\n<\/tr>\n<tr>\n<td>volatile<\/td>\n<td>\u6613\u5931<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>\u7a0b\u5e8f\u63a7\u5236\u8bed\u53e5<\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>break<\/td>\n<td>\u8df3\u51fa\u5faa\u73af<\/td>\n<\/tr>\n<tr>\n<td>case<\/td>\n<td>\u5b9a\u4e49\u4e00\u4e2a\u503c\u4ee5\u4f9b switch \u9009\u62e9<\/td>\n<\/tr>\n<tr>\n<td>continue<\/td>\n<td>\u7ee7\u7eed<\/td>\n<\/tr>\n<tr>\n<td>do<\/td>\n<td>\u8fd0\u884c<\/td>\n<\/tr>\n<tr>\n<td>else<\/td>\n<td>\u5426\u5219<\/td>\n<\/tr>\n<tr>\n<td>for<\/td>\n<td>\u5faa\u73af<\/td>\n<\/tr>\n<tr>\n<td>if<\/td>\n<td>\u5982\u679c<\/td>\n<\/tr>\n<tr>\n<td>instanceof<\/td>\n<td>\u5b9e\u4f8b<\/td>\n<\/tr>\n<tr>\n<td>return<\/td>\n<td>\u8fd4\u56de<\/td>\n<\/tr>\n<tr>\n<td>switch<\/td>\n<td>\u6839\u636e\u503c\u9009\u62e9\u6267\u884c<\/td>\n<\/tr>\n<tr>\n<td>while<\/td>\n<td>\u5faa\u73af<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>\u9519\u8bef\u5904\u7406<\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>assert<\/td>\n<td>\u65ad\u8a00\u8868\u8fbe\u5f0f\u662f\u5426\u4e3a\u771f<\/td>\n<\/tr>\n<tr>\n<td>catch<\/td>\n<td>\u6355\u6349\u5f02\u5e38<\/td>\n<\/tr>\n<tr>\n<td>finally<\/td>\n<td>\u6709\u6ca1\u6709\u5f02\u5e38\u90fd\u6267\u884c<\/td>\n<\/tr>\n<tr>\n<td>throw<\/td>\n<td>\u629b\u51fa\u4e00\u4e2a\u5f02\u5e38\u5bf9\u8c61<\/td>\n<\/tr>\n<tr>\n<td>throws<\/td>\n<td>\u58f0\u660e\u4e00\u4e2a\u5f02\u5e38\u53ef\u80fd\u88ab\u629b\u51fa<\/td>\n<\/tr>\n<tr>\n<td>try<\/td>\n<td>\u6355\u83b7\u5f02\u5e38<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>\u5305\u76f8\u5173<\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>import<\/td>\n<td>\u5f15\u5165<\/td>\n<\/tr>\n<tr>\n<td>package<\/td>\n<td>\u5305<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>\u57fa\u672c\u7c7b\u578b<\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>boolean<\/td>\n<td>\u5e03\u5c14\u578b<\/td>\n<\/tr>\n<tr>\n<td>byte<\/td>\n<td>\u5b57\u8282\u578b<\/td>\n<\/tr>\n<tr>\n<td>char<\/td>\n<td>\u5b57\u7b26\u578b<\/td>\n<\/tr>\n<tr>\n<td>double<\/td>\n<td>\u53cc\u7cbe\u5ea6\u6d6e\u70b9<\/td>\n<\/tr>\n<tr>\n<td>float<\/td>\n<td>\u5355\u7cbe\u5ea6\u6d6e\u70b9<\/td>\n<\/tr>\n<tr>\n<td>int<\/td>\n<td>\u6574\u578b<\/td>\n<\/tr>\n<tr>\n<td>long<\/td>\n<td>\u957f\u6574\u578b<\/td>\n<\/tr>\n<tr>\n<td>short<\/td>\n<td>\u77ed\u6574\u578b<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>\u53d8\u91cf\u5f15\u7528<\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>super<\/td>\n<td>\u7236\u7c7b\u3001\u8d85\u7c7b<\/td>\n<\/tr>\n<tr>\n<td>this<\/td>\n<td>\u672c\u7c7b<\/td>\n<\/tr>\n<tr>\n<td>void<\/td>\n<td>\u65e0\u8fd4\u56de\u503c<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>\u4fdd\u7559\u5173\u952e\u5b57<\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>goto<\/td>\n<td>\u662f\u5173\u952e\u5b57\uff0c\u4f46\u4e0d\u80fd\u4f7f\u7528<\/td>\n<\/tr>\n<tr>\n<td>const<\/td>\n<td>\u662f\u5173\u952e\u5b57\uff0c\u4f46\u4e0d\u80fd\u4f7f\u7528<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u6ce8\u610f\uff1aJava \u7684 null \u4e0d\u662f\u5173\u952e\u5b57\uff0c\u7c7b\u4f3c\u4e8e true \u548c false\uff0c\u5b83\u662f\u4e00\u4e2a\u5b57\u9762\u5e38\u91cf\uff0c\u4e0d\u5141\u8bb8\u4f5c\u4e3a\u6807\u8bc6\u7b26\u4f7f\u7528\u3002<\/p>\n<h2>\u6ce8\u91ca\uff1a<\/h2>\n<p>\u5355\u884c\uff1a<code>\/\/<\/code><\/p>\n<h2>\u591a\u884c\uff1a<code>\/**\/<\/code><br \/>\n\u7ee7\u627f(New):<\/h2>\n<p>\u5728 Java \u4e2d\uff0c\u4e00\u4e2a\u7c7b\u53ef\u4ee5\u7531\u5176\u4ed6\u7c7b\u6d3e\u751f\u3002\u5982\u679c\u4f60\u8981\u521b\u5efa\u4e00\u4e2a\u7c7b\uff0c\u800c\u4e14\u5df2\u7ecf\u5b58\u5728\u4e00\u4e2a\u7c7b\u5177\u6709\u4f60\u6240\u9700\u8981\u7684\u5c5e\u6027\u6216\u65b9\u6cd5\uff0c\u90a3\u4e48\u4f60\u53ef\u4ee5\u5c06\u65b0\u521b\u5efa\u7684\u7c7b\u7ee7\u627f\u8be5\u7c7b\u3002<\/p>\n<h2>\u5229\u7528\u7ee7\u627f\u7684\u65b9\u6cd5\uff0c\u53ef\u4ee5\u91cd\u7528\u5df2\u5b58\u5728\u7c7b\u7684\u65b9\u6cd5\u548c\u5c5e\u6027\uff0c\u800c\u4e0d\u7528\u91cd\u5199\u8fd9\u4e9b\u4ee3\u7801\u3002\u88ab\u7ee7\u627f\u7684\u7c7b\u79f0\u4e3a\u8d85\u7c7b\uff08super class\uff09\uff0c\u6d3e\u751f\u7c7b\u79f0\u4e3a\u5b50\u7c7b\uff08sub class\uff09\u3002<br \/>\n\u63a5\u53e3:<\/h2>\n<p>\u5728 Java \u4e2d\uff0c\u63a5\u53e3\u53ef\u7406\u89e3\u4e3a\u5bf9\u8c61\u95f4\u76f8\u4e92\u901a\u4fe1\u7684\u534f\u8bae\u3002\u63a5\u53e3\u5728\u7ee7\u627f\u4e2d\u626e\u6f14\u7740\u5f88\u91cd\u8981\u7684\u89d2\u8272\u3002<\/p>\n<p>\u63a5\u53e3\u53ea\u5b9a\u4e49\u6d3e\u751f\u8981\u7528\u5230\u7684\u65b9\u6cd5\uff0c\u4f46\u662f\u65b9\u6cd5\u7684\u5177\u4f53\u5b9e\u73b0\u5b8c\u5168\u53d6\u51b3\u4e8e\u6d3e\u751f\u7c7b\u3002<\/p>\n<h2>\u5bf9\u8c61\u548c\u7c7b\uff1a<\/h2>\n<p>java\u652f\u6301\u5bf9\u8c61\u548c\u7c7b\uff0c\u5176\u4e2d\u7c7b\u5b9a\u4e49\u5bf9\u8c61\u84dd\u56fe\uff08\u6a21\u677f\uff09\uff0c\u6709\u5c5e\u6027\u548c\u65b9\u6cd5\uff0c\u5bf9\u8c61\u662f\u7c7b\u7684\u5b9e\u4f8b\uff0c\u6709\u72b6\u6001\u548c\u884c\u4e3a<\/p>\n<p>\u7c7b\u7684\u7c7b\u578b\u53d8\u91cf\uff1a<\/p>\n<ul>\n<li><strong>\u5c40\u90e8\u53d8\u91cf<\/strong>\uff1a\u5728\u65b9\u6cd5\u3001\u6784\u9020\u65b9\u6cd5\u6216\u8005\u8bed\u53e5\u5757\u4e2d\u5b9a\u4e49\u7684\u53d8\u91cf\u88ab\u79f0\u4e3a\u5c40\u90e8\u53d8\u91cf\u3002\u53d8\u91cf\u58f0\u660e\u548c\u521d\u59cb\u5316\u90fd\u662f\u5728\u65b9\u6cd5\u4e2d\uff0c\u65b9\u6cd5\u7ed3\u675f\u540e\uff0c\u53d8\u91cf\u5c31\u4f1a\u81ea\u52a8\u9500\u6bc1\u3002<\/li>\n<li><strong>\u6210\u5458\u53d8\u91cf<\/strong>\uff1a\u6210\u5458\u53d8\u91cf\u662f\u5b9a\u4e49\u5728\u7c7b\u4e2d\uff0c\u65b9\u6cd5\u4f53\u4e4b\u5916\u7684\u53d8\u91cf\u3002\u8fd9\u79cd\u53d8\u91cf\u5728\u521b\u5efa\u5bf9\u8c61\u7684\u65f6\u5019\u5b9e\u4f8b\u5316\u3002\u6210\u5458\u53d8\u91cf\u53ef\u4ee5\u88ab\u7c7b\u4e2d\u65b9\u6cd5\u3001\u6784\u9020\u65b9\u6cd5\u548c\u7279\u5b9a\u7c7b\u7684\u8bed\u53e5\u5757\u8bbf\u95ee\u3002<\/li>\n<li><strong>\u7c7b\u53d8\u91cf<\/strong>\uff1a\u7c7b\u53d8\u91cf\u4e5f\u58f0\u660e\u5728\u7c7b\u4e2d\uff0c\u65b9\u6cd5\u4f53\u4e4b\u5916\uff0c\u4f46\u5fc5\u987b\u58f0\u660e\u4e3a static \u7c7b\u578b\u3002<\/li>\n<\/ul>\n<h3>\u65b9\u6cd5\uff1a<\/h3>\n<ul>\n<li>\u5b9a\u4e49\u7c7b\u7684\u884c\u4e3a\uff0c\u5305\u542b\u5728\u7c7b\u4e2d\u7684\u51fd\u6570\u3002<\/li>\n<li>\u793a\u4f8b\uff1a<code>public void displayInfo() { System.out.println(\"Info\"); }<\/code><\/li>\n<\/ul>\n<p>\u6784\u9020\u65b9\u6cd5\uff1a\u7528\u4e8e\u5728\u521b\u5efa\u5bf9\u8c61\u65f6\u4e3a\u5176\u521d\u59cb\u5316\u3002\u4e00\u4e2a\u7c7b\u90fd\u81f3\u5c11\u6709\u4e00\u4e2a\u4ee5\u4e0a\u7684\u6784\u9020\u65b9\u6cd5\uff0c\u82e5\u672a\u663e\u5f0f\u5b9a\u4e49\uff0c\u90a3\u4e48Java \u7f16\u8bd1\u5668\u5c06\u4f1a\u4e3a\u8be5\u7c7b\u63d0\u4f9b\u4e00\u4e2a\u9ed8\u8ba4\u6784\u9020\u65b9\u6cd5\u3002\u5728\u521b\u5efa\u4e00\u4e2a\u5bf9\u8c61\u7684\u65f6\u5019\uff0c\u81f3\u5c11\u8981\u8c03\u7528\u4e00\u4e2a\u6784\u9020\u65b9\u6cd5\u3002\u6784\u9020\u65b9\u6cd5\u7684\u540d\u79f0\u5fc5\u987b\u4e0e\u7c7b\u540c\u540d\u3002<\/p>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>public class Puppy{\n    public Puppy(){\n    }\n\n    public Puppy(String name){\n        \/\/ \u8fd9\u4e2a\u6784\u9020\u5668\u4ec5\u6709\u4e00\u4e2a\u53c2\u6570\uff1aname\n    }\n}<\/code><\/pre>\n<h3>\u521b\u5efa\u5bf9\u8c61\uff1a<\/h3>\n<p>\u5bf9\u8c61\u662f\u6839\u636e\u7c7b\u521b\u5efa\u7684\u3002\u5728Java\u4e2d\uff0c\u4f7f\u7528\u5173\u952e\u5b57 new \u6765\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5bf9\u8c61\u3002\u521b\u5efa\u5bf9\u8c61\u9700\u8981\u4ee5\u4e0b\u4e09\u6b65\uff1a<\/p>\n<ul>\n<li><strong>\u58f0\u660e<\/strong>\uff1a\u58f0\u660e\u4e00\u4e2a\u5bf9\u8c61\uff0c\u5305\u62ec\u5bf9\u8c61\u540d\u79f0\u548c\u5bf9\u8c61\u7c7b\u578b\u3002<\/li>\n<li><strong>\u5b9e\u4f8b\u5316<\/strong>\uff1a\u4f7f\u7528\u5173\u952e\u5b57 new \u6765\u521b\u5efa\u4e00\u4e2a\u5bf9\u8c61\u3002<\/li>\n<li><strong>\u521d\u59cb\u5316<\/strong>\uff1a\u4f7f\u7528 new \u521b\u5efa\u5bf9\u8c61\u65f6\uff0c\u4f1a\u8c03\u7528\u6784\u9020\u65b9\u6cd5\u521d\u59cb\u5316\u5bf9\u8c61\u3002<\/li>\n<\/ul>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>public class Puppy{\n   public Puppy(String name){\n      \/\/\u8fd9\u4e2a\u6784\u9020\u5668\u4ec5\u6709\u4e00\u4e2a\u53c2\u6570\uff1aname\n      System.out.println(\"\u5c0f\u72d7\u7684\u540d\u5b57\u662f : \" + name ); \n   }\n   public static void main(String[] args){\n      \/\/ \u4e0b\u9762\u7684\u8bed\u53e5\u5c06\u521b\u5efa\u4e00\u4e2aPuppy\u5bf9\u8c61\n      Puppy myPuppy = new Puppy( \"tommy\" );\n   }\n}<\/code><\/pre>\n<h3>\u5c01\u88c5\uff1a\u5c06\u5bf9\u8c61\u7684\u72b6\u6001\u79c1\u6709\u5316\uff0c\u7136\u540e\u901a\u8fc7\u516c\u5171\u65b9\u6cd5\u79c1\u6709\u5316<\/h3>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u4f8b\uff1a<\/p>\n<pre><code>private String name; \npublic String getName() { return name; }<\/code><\/pre>\n<h3>\u591a\u6001\uff1a<\/h3>\n<p>\u65b9\u6cd5\u53ef\u4ee5\u8868\u73b0\u4e3a\u591a\u79cd\u5f62\u6001\uff0c\u4e3b\u8981\u901a\u8fc7\u65b9\u6cd5\u91cd\u8f7d\u548c\u65b9\u6cd5\u91cd\u5199\u5b9e\u73b0<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u65b9\u6cd5\u91cd\u8f7d\uff1a\u5728<strong>\u540c\u4e00\u4e2a\u7c7b<\/strong>\u4e2d\uff0c\u5141\u8bb8\u5b58\u5728\u591a\u4e2a<strong>\u540c\u540d\u65b9\u6cd5<\/strong>\uff0c\u4f46\u8fd9\u4e9b\u65b9\u6cd5\u7684<strong>\u53c2\u6570\u5217\u8868\u5fc5\u987b\u4e0d\u540c<\/strong>\uff08\u53c2\u6570\u7c7b\u578b\u3001\u53c2\u6570\u4e2a\u6570\u6216\u53c2\u6570\u987a\u5e8f\u4e0d\u540c\uff09\u3002<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u4f8b\uff1a<\/p>\n<pre><code>public class Calculator {\n    \/\/ 1. \u53c2\u6570\u4e2a\u6570\u4e0d\u540c\n    public int add(int a, int b) {\n        return a + b;\n    }\n\n    public int add(int a, int b, int c) {\n        return a + b + c;\n    }\n\n    \/\/ 2. \u53c2\u6570\u7c7b\u578b\u4e0d\u540c\n    public double add(double a, double b) {\n        return a + b;\n    }\n\n    public String add(String a, String b) {\n        return a + b;\n    }\n\n    \/\/ 3. \u53c2\u6570\u987a\u5e8f\u4e0d\u540c\uff08\u6ce8\u610f\uff1a\u53ea\u6709\u5f53\u53c2\u6570\u7c7b\u578b\u4e0d\u540c\u65f6\u624d\u6709\u610f\u4e49\uff09\n    public void printInfo(String name, int age) {\n        System.out.println(\"Name: \" + name + \", Age: \" + age);\n    }\n\n    public void printInfo(int age, String name) {\n        System.out.println(\"Age: \" + age + \", Name: \" + name);\n    }\n\n}<\/code><\/pre>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u65b9\u6cd5\u91cd\u5199\uff1a<strong>\u5b50\u7c7b<\/strong>\u91cd\u65b0\u5b9a\u4e49<strong>\u7236\u7c7b<\/strong>\u4e2d\u5df2\u6709\u7684\u65b9\u6cd5\uff0c\u65b9\u6cd5\u540d\u3001\u53c2\u6570\u5217\u8868\u548c\u8fd4\u56de\u7c7b\u578b\u90fd\u5fc5\u987b\u76f8\u540c\uff0c\u4f46\u65b9\u6cd5\u4f53\uff08\u5b9e\u73b0\uff09\u4e0d\u540c\u3002<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u4f8b\uff1a<\/p>\n<pre><code>\/\/ \u7236\u7c7b\nclass Animal {\n    protected String name;\n\n    public Animal(String name) {\n        this.name = name;\n    }\n\n    \/\/ \u53ef\u88ab\u91cd\u5199\u7684\u65b9\u6cd5\n    public void makeSound() {\n        System.out.println(name + \" makes a sound\");\n    }\n\n    public Object getInfo() {\n        return \"Animal: \" + name;\n    }\n\n    \/\/ private\u65b9\u6cd5\u4e0d\u80fd\u88ab\u91cd\u5199\n    private void secretMethod() {\n        System.out.println(\"This is secret\");\n    }\n\n    \/\/ final\u65b9\u6cd5\u4e0d\u80fd\u88ab\u91cd\u5199\n    public final void sleep() {\n        System.out.println(name + \" is sleeping\");\n    }\n\n    \/\/ static\u65b9\u6cd5\u4e0d\u80fd\u88ab\u91cd\u5199\uff08\u4f46\u53ef\u4ee5\u88ab\u9690\u85cf\uff09\n    public static void eat() {\n        System.out.println(\"Animal is eating\");\n    }\n}\n\n\/\/ \u5b50\u7c7b\nclass Dog extends Animal {\n    public Dog(String name) {\n        super(name);\n    }\n\n    \/\/ \u2705 \u6b63\u786e\u91cd\u5199\uff1a\u8bbf\u95ee\u6743\u9650\u76f8\u540c\n    @Override\n    public void makeSound() {\n        System.out.println(name + \" barks: Woof! Woof!\");\n    }\n\n    \/\/ \u2705 \u534f\u53d8\u8fd4\u56de\u7c7b\u578b\uff1a\u8fd4\u56de\u7c7b\u578b\u662f\u7236\u7c7b\u8fd4\u56de\u7c7b\u578b\u7684\u5b50\u7c7b\n    @Override\n    public String getInfo() {\n        return \"Dog: \" + name;\n    }\n\n    \/\/ \u2705 \u8bbf\u95ee\u6743\u9650\u66f4\u5bbd\u677e\n    @Override\n    protected void makeSound() {  \/\/ \u274c \u9519\u8bef\uff01\u4e0d\u80fd\u66f4\u4e25\u683c\uff0c\u4f46\u53ef\u4ee5\u66f4\u5bbd\u677e\n        \/\/ \u5b9e\u9645\u4e0a\u8fd9\u91cc\u4f1a\u7f16\u8bd1\u9519\u8bef\uff0c\u56e0\u4e3a\u4ecepublic\u6539\u4e3aprotected\u662f\u66f4\u4e25\u683c\u4e86\n    }\n\n    \/\/ \u274c \u9519\u8bef\u793a\u4f8b\uff1a\u53c2\u6570\u5217\u8868\u4e0d\u540c\uff08\u8fd9\u662f\u91cd\u8f7d\uff0c\u4e0d\u662f\u91cd\u5199\uff09\n    public void makeSound(String sound) {\n        System.out.println(name + \" makes sound: \" + sound);\n    }\n\n    \/\/ static\u65b9\u6cd5\u7684\"\u91cd\u5199\"\u5b9e\u9645\u4e0a\u662f\u9690\u85cf\n    public static void eat() {\n        System.out.println(\"Dog is eating bones\");\n    }\n}<\/code><\/pre>\n<h3>\u62bd\u8c61\u7c7b\u548c\u63a5\u53e3\uff1a<\/h3>\n<p>\u62bd\u8c61\u7c7b\uff1a<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u5b9a\u4e49\uff1a\u7528 <code>abstract<\/code> \u5173\u952e\u5b57\u4fee\u9970\u7684\u7c7b\uff0c\u79f0\u4e3a\u62bd\u8c61\u7c7b\u3002  \u5b83<strong>\u4e0d\u80fd\u88ab\u76f4\u63a5\u5b9e\u4f8b\u5316<\/strong>\uff08\u4e0d\u80fd\u7528 <code>new Shape()<\/code> \u521b\u5efa\u5bf9\u8c61\uff09\u3002<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u7279\u70b9\uff1a<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01\uff1a\u53ef\u4ee5\u5305\u542b <strong>\u62bd\u8c61\u65b9\u6cd5<\/strong>\uff08\u53ea\u6709\u58f0\u660e\uff0c\u6ca1\u6709\u65b9\u6cd5\u4f53\uff09<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a02\uff1a\u4e5f\u53ef\u4ee5\u5305\u542b <strong>\u5177\u4f53\u65b9\u6cd5<\/strong>\uff08\u6709\u5b8c\u6574\u5b9e\u73b0\uff09<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a03\uff1a\u53ef\u4ee5\u6709\u5b57\u6bb5\u3001\u6784\u9020\u5668\u3001\u9759\u6001\u65b9\u6cd5\u7b49<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a04\uff1a\u5b50\u7c7b\u5fc5\u987b <strong>\u91cd\u5199\uff08override\uff09\u6240\u6709\u62bd\u8c61\u65b9\u6cd5<\/strong>\uff0c\u5426\u5219\u5b50\u7c7b\u4e5f\u5fc5\u987b\u58f0\u660e\u4e3a <code>abstract<\/code><\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u4f8b\uff1a<\/p>\n<pre><code>public abstract class Shape {\n    \/\/ \u62bd\u8c61\u65b9\u6cd5\uff1a\u6ca1\u6709\u65b9\u6cd5\u4f53\uff0c\u4ee5\u5206\u53f7\u7ed3\u675f\n    abstract void draw();\n\n    \/\/ \u5177\u4f53\u65b9\u6cd5\uff08\u53ef\u9009\uff09\n    public void display() {\n        System.out.println(\"This is a shape.\");\n    }\n} \n\n\/\/ \u274c \u9519\u8bef\uff1a\u4e0d\u80fd\u76f4\u63a5\u521b\u5efa\u62bd\u8c61\u7c7b\u7684\u5bf9\u8c61\n\/\/ Shape s = new Shape();  \/\/ \u7f16\u8bd1\u9519\u8bef\uff01\n\n\/\/ \u2705 \u6b63\u786e\uff1a\u521b\u5efa\u5b50\u7c7b\u5e76\u5b9e\u73b0\u62bd\u8c61\u65b9\u6cd5\nclass Circle extends Shape {\n    @Override\n    void draw() {\n        System.out.println(\"Drawing a circle.\");\n    }\n}\n\n\/\/ \u6d4b\u8bd5\npublic class Main {\n    public static void main(String[] args) {\n        Shape circle = new Circle(); \/\/ \u5411\u4e0a\u8f6c\u578b\n        circle.draw();   \/\/ \u8f93\u51fa: Drawing a circle.\n        circle.display(); \/\/ \u8f93\u51fa: This is a shape.\n    }\n} <\/code><\/pre>\n<p>\u63a5\u53e3\uff1a<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u5b9a\u4e49\uff1a\u63a5\u53e3\u662f\u4e00\u4e2a<strong>\u5b8c\u5168\u62bd\u8c61\u7684\u7c7b<\/strong>\uff0c\u7528\u4e8e\u5b9a\u4e49\u4e00\u7ec4<strong>\u884c\u4e3a\u89c4\u8303<\/strong>\u3002<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u7279\u70b9\uff1a<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01\uff1a\u6240\u6709\u65b9\u6cd5\u9ed8\u8ba4\u662f <code>public abstract<\/code>\uff08\u5373\u4f7f\u4e0d\u5199\uff09<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a02\uff1a\u6240\u6709\u5b57\u6bb5\u9ed8\u8ba4\u662f <code>public static final<\/code>\uff08\u5373\u5e38\u91cf\uff09<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a03\uff1a\u53ef\u4ee5\u6709 <code>default<\/code> \u65b9\u6cd5\uff08\u5e26\u5b9e\u73b0\uff09<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a04\uff1a\u53ef\u4ee5\u6709 <code>static<\/code> \u65b9\u6cd5\uff08\u5e26\u5b9e\u73b0\uff09<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a05\uff1a<strong>\u4e00\u4e2a\u7c7b\u53ef\u4ee5\u5b9e\u73b0\u591a\u4e2a\u63a5\u53e3<\/strong>\uff08\u89e3\u51b3 Java \u5355\u7ee7\u627f\u7684\u9650\u5236\uff09<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u4f8b\uff1a<\/p>\n<pre><code>public interface Animal {\n    \/\/ \u62bd\u8c61\u65b9\u6cd5\uff08\u9690\u5f0f public abstract\uff09\n    void eat();\n\n    \/\/ \u5e38\u91cf\uff08\u9690\u5f0f public static final\uff09\n    String CATEGORY = \"Living Being\";\n\n    \/\/ \u9ed8\u8ba4\u65b9\u6cd5\uff08Java 8+\uff09\n    default void breathe() {\n        System.out.println(\"Animal is breathing.\");\n    }\n} \n\nclass Dog implements Animal {\n    @Override\n    public void eat() {\n        System.out.println(\"Dog eats bones.\");\n    }\n\n    \/\/ breathe() \u65b9\u6cd5\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528\uff0c\u65e0\u9700\u91cd\u5199\n}\n\npublic class Main {\n    public static void main(String[] args) {\n        Dog dog = new Dog();\n        dog.eat();      \/\/ \u8f93\u51fa: Dog eats bones.\n        dog.breathe();  \/\/ \u8f93\u51fa: Animal is breathing.\n        System.out.println(Animal.CATEGORY); \/\/ \u8f93\u51fa: Living Being\n    }\n}<\/code><\/pre>\n<h3>\u53cd\u5c04\uff1a<\/h3>\n<p>Java \u53cd\u5c04\uff08Reflection\uff09\u662f\u4e00\u4e2a\u5f3a\u5927\u7684\u7279\u6027\uff0c\u5b83\u5141\u8bb8\u7a0b\u5e8f\u5728\u8fd0\u884c\u65f6\u67e5\u8be2\u3001\u8bbf\u95ee\u548c\u4fee\u6539\u7c7b\u3001\u63a5\u53e3\u3001\u5b57\u6bb5\u548c\u65b9\u6cd5\u7684\u4fe1\u606f\u3002\u53cd\u5c04\u63d0\u4f9b\u4e86\u4e00\u79cd\u52a8\u6001\u5730\u64cd\u4f5c\u7c7b\u7684\u80fd\u529b\uff0c\u8fd9\u5728\u5f88\u591a\u6846\u67b6\u548c\u5e93\u4e2d\u88ab\u5e7f\u6cdb\u4f7f\u7528\uff0c\u4f8b\u5982Spring\u6846\u67b6\u7684\u4f9d\u8d56\u6ce8\u5165\u3002<\/p>\n<h4>\u53cd\u5c04 API\uff1a<\/h4>\n<p>Java \u7684\u53cd\u5c04 API \u63d0\u4f9b\u4e86\u4e00\u7cfb\u5217\u7684\u7c7b\u548c\u63a5\u53e3\u6765\u64cd\u4f5c Class \u5bf9\u8c61\u3002\u4e3b\u8981\u7684\u7c7b\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><strong><code>java.lang.Class<\/code><\/strong>\uff1a\u8868\u793a\u7c7b\u7684\u5bf9\u8c61\u3002\u63d0\u4f9b\u4e86\u65b9\u6cd5\u6765\u83b7\u53d6\u7c7b\u7684\u5b57\u6bb5\u3001\u65b9\u6cd5\u3001\u6784\u9020\u51fd\u6570\u7b49\u3002<\/li>\n<li><strong><code>java.lang.reflect.Field<\/code><\/strong>\uff1a\u8868\u793a\u7c7b\u7684\u5b57\u6bb5\uff08\u5c5e\u6027\uff09\u3002\u63d0\u4f9b\u4e86\u8bbf\u95ee\u548c\u4fee\u6539\u5b57\u6bb5\u7684\u80fd\u529b\u3002<\/li>\n<li><strong><code>java.lang.reflect.Method<\/code><\/strong>\uff1a\u8868\u793a\u7c7b\u7684\u65b9\u6cd5\u3002\u63d0\u4f9b\u4e86\u8c03\u7528\u65b9\u6cd5\u7684\u80fd\u529b\u3002<\/li>\n<li><strong><code>java.lang.reflect.Constructor<\/code><\/strong>\uff1a\u8868\u793a\u7c7b\u7684\u6784\u9020\u51fd\u6570\u3002\u63d0\u4f9b\u4e86\u521b\u5efa\u5bf9\u8c61\u7684\u80fd\u529b\u3002<\/li>\n<\/ul>\n<h4>\u6d41\u7a0b\uff1a\u83b7\u53d6class\u5bf9\u8c61-&gt;\u83b7\u53d6\u6210\u5458\u4fe1\u606f-&gt;\u64cd\u4f5c\u6210\u5458<\/h4>\n<h4>\u83b7\u53d6class\u5bf9\u8c61\uff08\u4e09\u79cd\u65b9\u6cd5\uff09\uff1a<\/h4>\n<pre><code>\u901a\u8fc7\u7c7b\u5b57\u9762\u91cf\nClass&lt;?&gt; clazz = String.class;\n\n\u901a\u8fc7\u5bf9\u8c61\u5b9e\u4f8b\uff1a\nString str = \"Hello\";\nClass&lt;?&gt; clazz = str.getClass();\n\n\u901a\u8fc7 Class.forName() \u65b9\u6cd5\uff1a\nClass&lt;?&gt; clazz = Class.forName(\"java.lang.String\"); \n\n\/\/&lt;?&gt;\uff1a\u65e0\u754c\u901a\u914d\u7b26\uff0c\u8868\u793a\u53ef\u4ee5\u5f15\u7528\u4efb\u610f\u7c7b\u578b\u7684\u7c7b\u5bf9\u8c61<\/code><\/pre>\n<h4>\u521b\u5efa\u5bf9\u8c61\uff1a<\/h4>\n<pre><code>Class&lt;?&gt; clazz = Class.forName(\"java.lang.String\");\nObject obj = clazz.getDeclaredConstructor().newInstance();<\/code><\/pre>\n<h4>\u8bbf\u95ee\u5b57\u6bb5\uff1a<\/h4>\n<pre><code>Class&lt;?&gt; clazz = Person.class;\nField field = clazz.getDeclaredField(\"name\");\/\/\u6b64\u65f6filed\u4ee3\u8868name\u952e\u672c\u8eab\nfield.setAccessible(true); \/\/ \u5982\u679c\u5b57\u6bb5\u662f\u79c1\u6709\u7684\uff0c\u9700\u8981\u8bbe\u7f6e\u4e3a\u53ef\u8bbf\u95ee\nObject value = field.get(personInstance); \/\/ \u83b7\u53d6Person\u7c7b\u7684\u5b9e\u4f8bpersonInstance\u5bf9\u8c61\u7684name\u5b57\u6bb5\u503c\uff0c\u7528value\u50a8\u5b58\nfield.set(personInstance, \"New Name\"); \/\/ \u8bbe\u7f6epersonInstance\u5bf9\u8c61name\u952e\u65b0\u7684\u5b57\u6bb5\u503c<\/code><\/pre>\n<h4>\u8c03\u7528\u65b9\u6cd5\uff1a<\/h4>\n<pre><code>Class&lt;?&gt; clazz = Person.class;\nMethod method = clazz.getMethod(\"sayHello\");\nmethod.invoke(personInstance);\/\/\u5728\u8be5\u5b9e\u4f8b\u4e0a\u6267\u884csayHello\u65b9\u6cd5\n\nMethod methodWithArgs = clazz.getMethod(\"greet\", String.class);\nmethodWithArgs.invoke(personInstance, \"World\");\/\/\u7528World\u53c2\u6570\u6267\u884cgreet\u65b9\u6cd5<\/code><\/pre>\n<h4>\u83b7\u53d6\u6784\u9020\u53c2\u6570\uff1a<\/h4>\n<pre><code>Class&lt;?&gt; clazz = Person.class;\nConstructor&lt;?&gt; constructor = clazz.getConstructor(String.class, int.class);\/\/\u544a\u77e5\u53c2\u6570\u7c7b\u578b\nObject obj = constructor.newInstance(\"John\", 30);<\/code><\/pre>\n<h4>\u83b7\u53d6\u63a5\u53e3\u548c\u7236\u7c7b\uff1a<\/h4>\n<pre><code>Class&lt;?&gt; clazz = Person.class;\n\n\/\/ \u83b7\u53d6\u6240\u6709\u63a5\u53e3\nClass&lt;?&gt;[] interfaces = clazz.getInterfaces();\nfor (Class&lt;?&gt; i : interfaces) {\n    System.out.println(\"Interface: \" + i.getName());\n}\n\n\/\/ \u83b7\u53d6\u7236\u7c7b\nClass&lt;?&gt; superClass = clazz.getSuperclass();\nSystem.out.println(\"Superclass: \" + superClass.getName());<\/code><\/pre>\n<h4><code>java.lang.reflect<\/code>\u00a0\u5305\u4e2d\u7684\u4e3b\u8981\u7c7b\u548c\u63a5\u53e3\u7684\u8be6\u7ec6\u4ecb\u7ecd\uff1a<\/h4>\n<p>1.\u00a0<strong><code>Class<\/code>\u00a0\u7c7b<\/strong><\/p>\n<ul>\n<li><strong>\u529f\u80fd<\/strong>\uff1a\u8868\u793a\u7c7b\u7684\u5bf9\u8c61\uff0c\u63d0\u4f9b\u4e86\u83b7\u53d6\u7c7b\u4fe1\u606f\u7684\u65b9\u6cd5\uff0c\u5982\u5b57\u6bb5\u3001\u65b9\u6cd5\u3001\u6784\u9020\u51fd\u6570\u7b49\u3002<\/li>\n<li><strong>\u4e3b\u8981\u65b9\u6cd5<\/strong>\uff1a\n<ul>\n<li><code>getFields()<\/code>\uff1a\u83b7\u53d6\u6240\u6709\u516c\u5171\u5b57\u6bb5\u3002<\/li>\n<li><code>getDeclaredFields()<\/code>\uff1a\u83b7\u53d6\u6240\u6709\u58f0\u660e\u7684\u5b57\u6bb5\uff0c\u5305\u62ec\u79c1\u6709\u5b57\u6bb5\u3002<\/li>\n<li><code>getMethods()<\/code>\uff1a\u83b7\u53d6\u6240\u6709\u516c\u5171\u65b9\u6cd5\u3002<\/li>\n<li><code>getDeclaredMethods()<\/code>\uff1a\u83b7\u53d6\u6240\u6709\u58f0\u660e\u7684\u65b9\u6cd5\uff0c\u5305\u62ec\u79c1\u6709\u65b9\u6cd5\u3002<\/li>\n<li><code>getConstructors()<\/code>\uff1a\u83b7\u53d6\u6240\u6709\u516c\u5171\u6784\u9020\u51fd\u6570\u3002<\/li>\n<li><code>getDeclaredConstructors()<\/code>\uff1a\u83b7\u53d6\u6240\u6709\u58f0\u660e\u7684\u6784\u9020\u51fd\u6570\uff0c\u5305\u62ec\u79c1\u6709\u6784\u9020\u51fd\u6570\u3002<\/li>\n<li><code>getSuperclass()<\/code>\uff1a\u83b7\u53d6\u7c7b\u7684\u7236\u7c7b\u3002<\/li>\n<li><code>getInterfaces()<\/code>\uff1a\u83b7\u53d6\u7c7b\u5b9e\u73b0\u7684\u6240\u6709\u63a5\u53e3\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>2.\u00a0<strong><code>Field<\/code>\u00a0\u7c7b<\/strong><\/p>\n<ul>\n<li><strong>\u529f\u80fd<\/strong>\uff1a\u8868\u793a\u7c7b\u7684\u5b57\u6bb5\uff08\u5c5e\u6027\uff09\uff0c\u63d0\u4f9b\u4e86\u8bbf\u95ee\u548c\u4fee\u6539\u5b57\u6bb5\u503c\u7684\u65b9\u6cd5\u3002<\/li>\n<li><strong>\u4e3b\u8981\u65b9\u6cd5<\/strong>\uff1a\n<ul>\n<li><code>get(Object obj)<\/code>\uff1a\u83b7\u53d6\u6307\u5b9a\u5bf9\u8c61\u7684\u5b57\u6bb5\u503c\u3002<\/li>\n<li><code>set(Object obj, Object value)<\/code>\uff1a\u8bbe\u7f6e\u6307\u5b9a\u5bf9\u8c61\u7684\u5b57\u6bb5\u503c\u3002<\/li>\n<li><code>getType()<\/code>\uff1a\u83b7\u53d6\u5b57\u6bb5\u7684\u6570\u636e\u7c7b\u578b\u3002<\/li>\n<li><code>getModifiers()<\/code>\uff1a\u83b7\u53d6\u5b57\u6bb5\u7684\u4fee\u9970\u7b26\uff08\u5982 public\u3001private\uff09\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>3.\u00a0<strong><code>Method<\/code>\u00a0\u7c7b<\/strong><\/p>\n<ul>\n<li><strong>\u529f\u80fd<\/strong>\uff1a\u8868\u793a\u7c7b\u7684\u65b9\u6cd5\uff0c\u63d0\u4f9b\u4e86\u8c03\u7528\u65b9\u6cd5\u7684\u80fd\u529b\u3002<\/li>\n<li><strong>\u4e3b\u8981\u65b9\u6cd5<\/strong>\uff1a\n<ul>\n<li><code>invoke(Object obj, Object... args)<\/code>\uff1a\u8c03\u7528\u6307\u5b9a\u5bf9\u8c61\u7684\u65b9\u6cd5\u3002<\/li>\n<li><code>getReturnType()<\/code>\uff1a\u83b7\u53d6\u65b9\u6cd5\u7684\u8fd4\u56de\u7c7b\u578b\u3002<\/li>\n<li><code>getParameterTypes()<\/code>\uff1a\u83b7\u53d6\u65b9\u6cd5\u7684\u53c2\u6570\u7c7b\u578b\u3002<\/li>\n<li><code>getModifiers()<\/code>\uff1a\u83b7\u53d6\u65b9\u6cd5\u7684\u4fee\u9970\u7b26\uff08\u5982 public\u3001private\uff09\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>4.\u00a0<strong><code>Constructor<\/code>\u00a0\u7c7b<\/strong><\/p>\n<ul>\n<li><strong>\u529f\u80fd<\/strong>\uff1a\u8868\u793a\u7c7b\u7684\u6784\u9020\u51fd\u6570\uff0c\u63d0\u4f9b\u4e86\u521b\u5efa\u5bf9\u8c61\u7684\u80fd\u529b\u3002<\/li>\n<li><strong>\u4e3b\u8981\u65b9\u6cd5<\/strong>\uff1a\n<ul>\n<li><code>newInstance(Object... initargs)<\/code>\uff1a\u521b\u5efa\u4e00\u4e2a\u65b0\u5b9e\u4f8b\uff0c\u4f7f\u7528\u6307\u5b9a\u7684\u6784\u9020\u51fd\u6570\u53c2\u6570\u3002<\/li>\n<li><code>getParameterTypes()<\/code>\uff1a\u83b7\u53d6\u6784\u9020\u51fd\u6570\u7684\u53c2\u6570\u7c7b\u578b\u3002<\/li>\n<li><code>getModifiers()<\/code>\uff1a\u83b7\u53d6\u6784\u9020\u51fd\u6570\u7684\u4fee\u9970\u7b26\uff08\u5982 public\u3001private\uff09\u3002 <\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h4>\u7528\u53cd\u5c04\u52a8\u6001\u6267\u884cshell\uff1a<\/h4>\n<pre><code>Class.forName(\"java.lang.Runtime\").getMethod(\"exec\", String.class).invoke(Class.forName(\"java.lang.Runtime\").getMethod(\"getRuntime\").invoke(Class.forName(\"java.lang.Runtime\")),\"cmd \/c start\"); \n\/\/\u83b7\u53d6Runtime\u7c7b\u7684exec\u65b9\u6cd5\u5e76\u8c03\u7528\uff0c\u7531\u4e8eexec\u662f\u5b9e\u4f8b\u65b9\u6cd5\uff0c\u5fc5\u987b\u4f9d\u9644\u4e8e\u5bf9\u8c61\u8fd0\u884c\uff0c\u6545\u4f20\u5165\u4e00\u4e2a\u8c03\u7528Runtime\u7684getRuntime\u65b9\u6cd5\u5f97\u5230\u7684runtime\u5355\u4f8b\uff0c\u540c\u65f6\u4f20\u5165\u8981\u6267\u884c\u7684\u547d\u4ee4\u53c2\u6570<\/code><\/pre>\n<h4>\u5229\u7528\u53cd\u5c04\u4fee\u6539final\u4fee\u9970\u5b57\u6bb5\uff1a<\/h4>\n<pre><code>class Example {\n    private final String message = \"Initial Value\";\n\n    public String getMessage() {\n        return message;\n    }\n}\n\npublic class ModifyFinalField {\n    public static void main(String[] args) throws Exception {\n        Example example = new Example();\n        \/\/ \u8f93\u51fa\u539f\u59cb\u503c\n        System.out.println(\"Before modification: \" + example.getMessage());\n        \/\/ \u83b7\u53d6 Example \u7c7b\u4e2d message \u5b57\u6bb5\u7684 Field \u5bf9\u8c61\n        Field messageField = Example.class.getDeclaredField(\"message\");\n        \/\/ \u8bbe\u7f6e\u4e3a\u53ef\u8bbf\u95ee\n        messageField.setAccessible(true);\n        \/\/ \u4fee\u6539 final \u5b57\u6bb5\u7684\u503c\n        Field modifiersField = Field.class.getDeclaredField(\"modifiers\"); \n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/\u8fd9\u4e2a modifiers \u5b57\u6bb5\u5b58\u50a8\u4e86\u5f53\u524d\u5b57\u6bb5\u7684\u6240\u6709\u4fee\u9970\u7b26\u6807\u5fd7\u4f4d\uff08\u5982 private=2, final=16, static=8 \u7b49\u7684\u4e8c\u8fdb\u5236\u7ec4\u5408\uff09\u3002\n        modifiersField.setAccessible(true);\n        \/\/ \u6e05\u9664 final \u4fee\u9970\u7b26\u7684\u5f71\u54cd\n        modifiersField.setInt(messageField, messageField.getModifiers() &amp; ~java.lang.reflect.Modifier.FINAL);\n        \/\/\u6309\u4f4d\u4e0e\u8fd0\u7b97\u3002\u8fd9\u5c06\u4fdd\u7559\u5176\u4ed6\u6240\u6709\u6807\u5fd7\u4f4d\uff0c\u4f46\u5f3a\u5236\u5c06 FINAL \u5bf9\u5e94\u7684\u90a3\u4e00\u4f4d\u53d8\u6210 0\uff0c\u4fee\u6539\u5b57\u6bb5\u503c\u4fee\u6539\u5b57\u6bb5\u503c\u540e\u4e0d\u5728\u518d\u88ab\u8ba4\u4e3a\u662ffinal\n        messageField.set(example, \"Modified Value\");\n        \/\/ \u8f93\u51fa\u4fee\u6539\u540e\u7684\u503c\n        System.out.println(\"After modification: \" + example.getMessage());\n    }\n}\n<\/code><\/pre>\n<h3>\u6e90\u6587\u4ef6\u58f0\u660e\u89c4\u5219\uff1a<\/h3>\n<p>\u6700\u540e\uff0c\u6211\u4eec\u5c06\u5b66\u4e60\u6e90\u6587\u4ef6\u7684\u58f0\u660e\u89c4\u5219\u3002\u5f53\u5728\u4e00\u4e2a\u6e90\u6587\u4ef6\u4e2d\u5b9a\u4e49\u591a\u4e2a\u7c7b\uff0c\u5e76\u4e14\u8fd8\u6709 import \u8bed\u53e5\u548c package \u8bed\u53e5\u65f6\uff0c\u8981\u7279\u522b\u6ce8\u610f\u8fd9\u4e9b\u89c4\u5219\u3002<\/p>\n<ul>\n<li>\u4e00\u4e2a\u6e90\u6587\u4ef6\u4e2d\u53ea\u80fd\u6709\u4e00\u4e2a public \u7c7b<\/li>\n<li>\u4e00\u4e2a\u6e90\u6587\u4ef6\u53ef\u4ee5\u6709\u591a\u4e2a\u975e public \u7c7b<\/li>\n<li>\u6e90\u6587\u4ef6\u7684\u540d\u79f0\u5e94\u8be5\u548c public \u7c7b\u7684\u7c7b\u540d\u4fdd\u6301\u4e00\u81f4\u3002\u4f8b\u5982\uff1a\u6e90\u6587\u4ef6\u4e2d public \u7c7b\u7684\u7c7b\u540d\u662f Employee\uff0c\u90a3\u4e48\u6e90\u6587\u4ef6\u5e94\u8be5\u547d\u540d\u4e3aEmployee.java\u3002<\/li>\n<li>\u5982\u679c\u4e00\u4e2a\u7c7b\u5b9a\u4e49\u5728\u67d0\u4e2a\u5305\u4e2d\uff0c\u90a3\u4e48 package \u8bed\u53e5\u5e94\u8be5\u5728\u6e90\u6587\u4ef6\u7684\u9996\u884c\u3002<\/li>\n<li>\u5982\u679c\u6e90\u6587\u4ef6\u5305\u542b import \u8bed\u53e5\uff0c\u90a3\u4e48\u5e94\u8be5\u653e\u5728 package \u8bed\u53e5\u548c\u7c7b\u5b9a\u4e49\u4e4b\u95f4\u3002\u5982\u679c\u6ca1\u6709 package \u8bed\u53e5\uff0c\u90a3\u4e48 import \u8bed\u53e5\u5e94\u8be5\u5728\u6e90\u6587\u4ef6\u4e2d\u6700\u524d\u9762\u3002<\/li>\n<li>import \u8bed\u53e5\u548c package \u8bed\u53e5\u5bf9\u6e90\u6587\u4ef6\u4e2d\u5b9a\u4e49\u7684\u6240\u6709\u7c7b\u90fd\u6709\u6548\u3002\u5728\u540c\u4e00\u6e90\u6587\u4ef6\u4e2d\uff0c\u4e0d\u80fd\u7ed9\u4e0d\u540c\u7684\u7c7b\u4e0d\u540c\u7684\u5305\u58f0\u660e\u3002<\/li>\n<\/ul>\n<p>\u7c7b\u6709\u82e5\u5e72\u79cd\u8bbf\u95ee\u7ea7\u522b\uff0c\u5e76\u4e14\u7c7b\u4e5f\u5206\u4e0d\u540c\u7684\u7c7b\u578b\uff1a\u62bd\u8c61\u7c7b\u548c final \u7c7b\u7b49\u3002\u8fd9\u4e9b\u5c06\u5728\u8bbf\u95ee\u63a7\u5236\u7ae0\u8282\u4ecb\u7ecd\u3002<\/p>\n<p>\u9664\u4e86\u4e0a\u9762\u63d0\u5230\u7684\u51e0\u79cd\u7c7b\u578b\uff0cJava \u8fd8\u6709\u4e00\u4e9b\u7279\u6b8a\u7684\u7c7b\uff0c\u5982\uff1a<a href=\"https:\/\/www.runoob.com\/java\/java-inner-class.html\">\u5185\u90e8\u7c7b<\/a>\u3001<a href=\"https:\/\/www.runoob.com\/java\/java-anonymous-class.html\">\u533f\u540d\u7c7b<\/a>\u3002<\/p>\n<h2>\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff1a<\/h2>\n<p>\u6574\u6570\uff1a<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0byte\uff1a-128\u5230127<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u4f8b\uff1a<code>byte a = 100\uff0cbyte b = -50<\/code><\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0short\uff1a-32768\u523032767<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u4f8b\uff1a<code>short s = 1000\uff0cshort r = -20000<\/code><\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0int\uff1a-2,147,483,648\u52302,147,483,647<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u4f8b\uff1a<code>int a = 100000, int b = -200000<\/code><\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0long\uff1a-9,223,372,036,854,775,808\u52309,223,372,036,854,775,807<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u4f8b\uff1a<code>long a = 100000L\uff0clong b = -200000L<\/code><\/p>\n<p>\u6d6e\u70b9\u6570\uff1a<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0float\uff1a1.17549435e-38 \u5230 3.4028235e38<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u4f8b\uff1a<code>float f1 = 234.5f<\/code><\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0double\uff1a2.2250738585072014 \u00d7 10\u207b\u00b3\u2070\u2078\u52301.7976931348623157 \u00d7 10\u00b3\u2070\u2078<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u4f8b\uff1a<code>double   d3  =  8.0d<\/code><\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0boolean\uff1a\u5e03\u5c14\u503c\uff0c\u53ea\u6709true\/false\uff0c\u9ed8\u8ba4\u4e3afalse<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0char\uff1a\u7565<\/p>\n<h2>\u53d8\u91cf\uff1a<\/h2>\n<p>\u5728 Java \u8bed\u8a00\u4e2d\uff0c\u6240\u6709\u7684\u53d8\u91cf\u5728\u4f7f\u7528\u524d\u5fc5\u987b\u58f0\u660e\u3002<\/p>\n<p>\u58f0\u660e\u53d8\u91cf\u7684\u57fa\u672c\u683c\u5f0f\u5982\u4e0b\uff1a<\/p>\n<p><code>type identifier = value;<\/code><\/p>\n<p><strong>\u683c\u5f0f\u8bf4\u660e\uff1a<\/strong><\/p>\n<ul>\n<li>type &#8212; \u6570\u636e\u7c7b\u578b\u3002<\/li>\n<li>identifier &#8212; \u662f\u53d8\u91cf\u540d\uff0c\u53ef\u4ee5\u4f7f\u7528\u9017\u53f7\u00a0,\u00a0\u9694\u5f00\u6765\u58f0\u660e\u591a\u4e2a\u540c\u7c7b\u578b\u53d8\u91cf\u3002<\/li>\n<\/ul>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u4f8b\uff1a<\/p>\n<pre><code>int a, b, c;         \/\/ \u58f0\u660e\u4e09\u4e2aint\u578b\u6574\u6570\uff1aa\u3001 b\u3001c\nint d = 3, e = 4, f = 5; \/\/ \u58f0\u660e\u4e09\u4e2a\u6574\u6570\u5e76\u8d4b\u4e88\u521d\u503c\nbyte z = 22;         \/\/ \u58f0\u660e\u5e76\u521d\u59cb\u5316 z\nString s = \"runoob\";  \/\/ \u58f0\u660e\u5e76\u521d\u59cb\u5316\u5b57\u7b26\u4e32 s\ndouble pi = 3.14159; \/\/ \u58f0\u660e\u4e86\u53cc\u7cbe\u5ea6\u6d6e\u70b9\u578b\u53d8\u91cf pi\nchar x = 'x';        \/\/ \u58f0\u660e\u53d8\u91cf x \u7684\u503c\u662f\u5b57\u7b26 'x'\u3002<\/code><\/pre>\n<p>Java \u8bed\u8a00\u652f\u6301\u7684\u53d8\u91cf\u7c7b\u578b\u6709\uff1a<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u5c40\u90e8\u53d8\u91cf\uff08Local Variables\uff09\uff1a\u5c40\u90e8\u53d8\u91cf\u662f\u5728\u65b9\u6cd5\u3001\u6784\u9020\u51fd\u6570\u6216\u5757\u5185\u90e8\u58f0\u660e\u7684\u53d8\u91cf\uff0c\u5b83\u4eec\u5728\u58f0\u660e\u7684\u65b9\u6cd5\u3001\u6784\u9020\u51fd\u6570\u6216\u5757\u6267\u884c\u7ed3\u675f\u540e\u88ab\u9500\u6bc1\uff0c\u5c40\u90e8\u53d8\u91cf\u5728\u58f0<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u660e\u65f6\u9700\u8981\u521d\u59cb\u5316\uff0c\u5426\u5219\u4f1a\u5bfc\u81f4\u7f16\u8bd1\u9519\u8bef\u3002<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u5b9e\u4f8b\u53d8\u91cf\uff08Instance Variables\uff09\uff1a\u5b9e\u4f8b\u53d8\u91cf\u662f\u5728\u7c7b\u4e2d\u58f0\u660e\uff0c\u4f46\u5728\u65b9\u6cd5\u3001\u6784\u9020\u51fd\u6570\u6216\u5757\u4e4b\u5916\uff0c\u5b83\u4eec\u5c5e\u4e8e\u7c7b\u7684\u5b9e\u4f8b\uff0c\u6bcf\u4e2a\u7c7b\u7684\u5b9e\u4f8b\u90fd\u6709\u81ea\u5df1\u7684\u526f\u672c\uff0c\u5982\u679c\u4e0d\u660e<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u786e\u521d\u59cb\u5316\uff0c\u5b9e\u4f8b\u53d8\u91cf\u4f1a\u88ab\u8d4b\u4e88\u9ed8\u8ba4\u503c\uff08\u6570\u503c\u7c7b\u578b\u4e3a0\uff0cboolean\u7c7b\u578b\u4e3afalse\uff0c\u5bf9\u8c61\u5f15\u7528\u7c7b\u578b\u4e3anull\uff09\u3002<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u9759\u6001\u53d8\u91cf\u6216\u7c7b\u53d8\u91cf\uff08Class Variables\uff09\uff1a\u7c7b\u53d8\u91cf\u662f\u5728\u7c7b\u4e2d\u7528 static \u5173\u952e\u5b57\u58f0\u660e\u7684\u53d8\u91cf\uff0c\u5b83\u4eec\u5c5e\u4e8e\u7c7b\u800c\u4e0d\u662f\u5b9e\u4f8b\uff0c\u6240\u6709\u8be5\u7c7b\u7684\u5b9e\u4f8b\u5171\u4eab\u540c\u4e00\u4e2a\u7c7b\u53d8\u91cf\u7684\u503c\uff0c<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u7c7b\u53d8\u91cf\u5728\u7c7b\u52a0\u8f7d\u65f6\u88ab\u521d\u59cb\u5316\uff0c\u800c\u4e14\u53ea\u521d\u59cb\u5316\u4e00\u6b21\u3002<\/p>\n<p>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u53c2\u6570\u53d8\u91cf\uff08Parameters\uff09\uff1a\u53c2\u6570\u662f\u65b9\u6cd5\u6216\u6784\u9020\u51fd\u6570\u58f0\u660e\u4e2d\u7684\u53d8\u91cf\uff0c\u7528\u4e8e\u63a5\u6536\u8c03\u7528\u8be5\u65b9\u6cd5\u6216\u6784\u9020\u51fd\u6570\u65f6\u4f20\u9012\u7684\u503c\uff0c\u53c2\u6570\u53d8\u91cf\u7684\u4f5c\u7528\u57df\u53ea\u9650\u4e8e\u65b9\u6cd5\u5185\u90e8\u3002<\/p>\n<h2>\u4fee\u9970\u7b26\uff1a<\/h2>\n<h3>\u8bbf\u95ee\u4fee\u9970\u7b26\uff1a<\/h3>\n<p>\u7c7b\u578b\uff1a<\/p>\n<ul>\n<li>\n<p><strong>default<\/strong>\u00a0(\u5373\u9ed8\u8ba4\uff0c\u4ec0\u4e48\u4e5f\u4e0d\u5199\uff09: \u5728\u540c\u4e00\u5305\u5185\u53ef\u89c1\uff0c\u4e0d\u4f7f\u7528\u4efb\u4f55\u4fee\u9970\u7b26\u3002\u4f7f\u7528\u5bf9\u8c61\uff1a\u7c7b\u3001\u63a5\u53e3\u3001\u53d8\u91cf\u3001\u65b9\u6cd5\u3002<\/p>\n<\/li>\n<li>\n<p><strong>private<\/strong>\u00a0: \u5728\u540c\u4e00\u7c7b\u5185\u53ef\u89c1\u3002\u4f7f\u7528\u5bf9\u8c61\uff1a\u53d8\u91cf\u3001\u65b9\u6cd5\u3002\u00a0<strong>\u6ce8\u610f\uff1a\u4e0d\u80fd\u4fee\u9970\u7c7b\uff08\u5916\u90e8\u7c7b\uff09<\/strong><\/p>\n<\/li>\n<li>\n<p><strong>public<\/strong>\u00a0: \u5bf9\u6240\u6709\u7c7b\u53ef\u89c1\u3002\u4f7f\u7528\u5bf9\u8c61\uff1a\u7c7b\u3001\u63a5\u53e3\u3001\u53d8\u91cf\u3001\u65b9\u6cd5<\/p>\n<\/li>\n<li>\n<p><strong>protected<\/strong>\u00a0: \u5bf9\u540c\u4e00\u5305\u5185\u7684\u7c7b\u548c\u6240\u6709\u5b50\u7c7b\u53ef\u89c1\u3002\u4f7f\u7528\u5bf9\u8c61\uff1a\u53d8\u91cf\u3001\u65b9\u6cd5\u3002\u00a0<strong>\u6ce8\u610f\uff1a\u4e0d\u80fd\u4fee\u9970\u7c7b\uff08\u5916\u90e8\u7c7b\uff09<\/strong><\/p>\n<\/li>\n<\/ul>\n<p>\u8bbf\u95ee\u4fee\u9970\u7b26\u7684\u7ee7\u627f\uff1a<\/p>\n<ul>\n<li>\n<p>\u7236\u7c7b\u4e2d\u58f0\u660e\u4e3a public \u7684\u65b9\u6cd5\u5728\u5b50\u7c7b\u4e2d\u4e5f\u5fc5\u987b\u4e3a public\u3002<\/p>\n<\/li>\n<li>\n<p>\u7236\u7c7b\u4e2d\u58f0\u660e\u4e3a protected \u7684\u65b9\u6cd5\u5728\u5b50\u7c7b\u4e2d\u8981\u4e48\u58f0\u660e\u4e3a protected\uff0c\u8981\u4e48\u58f0\u660e\u4e3a public\uff0c\u4e0d\u80fd\u58f0\u660e\u4e3a private\u3002<\/p>\n<\/li>\n<li>\n<p>\u7236\u7c7b\u4e2d\u58f0\u660e\u4e3a private \u7684\u65b9\u6cd5\uff0c\u4e0d\u80fd\u591f\u88ab\u5b50\u7c7b\u7ee7\u627f\u3002<\/p>\n<\/li>\n<\/ul>\n<h3>\u975e\u8bbf\u95ee\u4fee\u9970\u7b26\uff1a<\/h3>\n<ul>\n<li>\n<p>static \u4fee\u9970\u7b26\uff0c\u7528\u6765\u4fee\u9970\u7c7b\u65b9\u6cd5\u548c\u7c7b\u53d8\u91cf\u3002<\/p>\n<ul>\n<li>\n<p><strong>\u9759\u6001\u53d8\u91cf\uff1a<\/strong><br \/>\nstatic \u5173\u952e\u5b57\u7528\u6765\u58f0\u660e\u72ec\u7acb\u4e8e\u5bf9\u8c61\u7684\u9759\u6001\u53d8\u91cf\uff0c\u65e0\u8bba\u4e00\u4e2a\u7c7b\u5b9e\u4f8b\u5316\u591a\u5c11\u5bf9\u8c61\uff0c\u5b83\u7684\u9759\u6001\u53d8\u91cf\u53ea\u6709\u4e00\u4efd\u62f7\u8d1d\u3002 \u9759\u6001\u53d8\u91cf\u4e5f\u88ab\u79f0\u4e3a\u7c7b\u53d8\u91cf\u3002\u5c40\u90e8\u53d8\u91cf\u4e0d\u80fd\u88ab\u58f0\u660e\u4e3a static \u53d8\u91cf\u3002<\/p>\n<\/li>\n<li>\n<p><strong>\u9759\u6001\u65b9\u6cd5\uff1a<\/strong><br \/>\nstatic \u5173\u952e\u5b57\u7528\u6765\u58f0\u660e\u72ec\u7acb\u4e8e\u5bf9\u8c61\u7684\u9759\u6001\u65b9\u6cd5\u3002\u9759\u6001\u65b9\u6cd5\u4e0d\u80fd\u4f7f\u7528\u7c7b\u7684\u975e\u9759\u6001\u53d8\u91cf\u3002\u9759\u6001\u65b9\u6cd5\u4ece\u53c2\u6570\u5217\u8868\u5f97\u5230\u6570\u636e\uff0c\u7136\u540e\u8ba1\u7b97\u8fd9\u4e9b\u6570\u636e\u3002<\/p>\n<\/li>\n<\/ul>\n<\/li>\n<li>\n<p>final \u4fee\u9970\u7b26\uff0c\u7528\u6765\u4fee\u9970\u7c7b\u3001\u65b9\u6cd5\u548c\u53d8\u91cf\uff0cfinal \u4fee\u9970\u7684\u7c7b\u4e0d\u80fd\u591f\u88ab\u7ee7\u627f\uff0c\u4fee\u9970\u7684\u65b9\u6cd5\u4e0d\u80fd\u88ab\u7ee7\u627f\u7c7b\u91cd\u65b0\u5b9a\u4e49\uff0c\u4fee\u9970\u7684\u53d8\u91cf\u4e3a\u5e38\u91cf\uff0c\u662f\u4e0d\u53ef\u4fee\u6539\u7684\u3002<\/p>\n<\/li>\n<li>\n<p>abstract \u4fee\u9970\u7b26\uff0c\u7528\u6765\u521b\u5efa\u62bd\u8c61\u7c7b\u548c\u62bd\u8c61\u65b9\u6cd5\u3002<\/p>\n<\/li>\n<li>\n<p>synchronized \u548c volatile \u4fee\u9970\u7b26\uff0c\u4e3b\u8981\u7528\u4e8e\u7ebf\u7a0b\u7684\u7f16\u7a0b\u3002<\/p>\n<ul>\n<li>\n<p>synchronized \u5173\u952e\u5b57\u58f0\u660e\u7684\u65b9\u6cd5\u540c\u4e00\u65f6\u95f4\u53ea\u80fd\u88ab\u4e00\u4e2a\u7ebf\u7a0b\u8bbf\u95ee\u3002synchronized \u4fee\u9970\u7b26\u53ef\u4ee5\u5e94\u7528\u4e8e\u56db\u4e2a\u8bbf\u95ee\u4fee\u9970\u7b26\u3002<\/p>\n<\/li>\n<li>\n<p>volatile \u4fee\u9970\u7684\u6210\u5458\u53d8\u91cf\u5728\u6bcf\u6b21\u88ab\u7ebf\u7a0b\u8bbf\u95ee\u65f6\uff0c\u90fd\u5f3a\u5236\u4ece\u5171\u4eab\u5185\u5b58\u4e2d\u91cd\u65b0\u8bfb\u53d6\u8be5\u6210\u5458\u53d8\u91cf\u7684\u503c\u3002\u800c\u4e14\uff0c\u5f53\u6210\u5458\u53d8\u91cf\u53d1\u751f\u53d8\u5316\u65f6\uff0c\u4f1a\u5f3a\u5236\u7ebf\u7a0b\u5c06\u53d8\u5316\u503c\u56de\u5199\u5230\u5171\u4eab\u5185\u5b58\u3002\u8fd9\u6837\u5728\u4efb\u4f55\u65f6\u523b\uff0c\u4e24\u4e2a\u4e0d\u540c\u7684\u7ebf\u7a0b\u603b\u662f\u770b\u5230\u67d0\u4e2a\u6210\u5458\u53d8\u91cf\u7684\u540c\u4e00\u4e2a\u503c\u3002<\/p>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>synchronized \u548c volatile \u4fee\u9970\u7b26\u7684\u4f8b\u5b50\uff1a<\/p>\n<pre><code>\/\/synchronized\npublic synchronized void showDetails(){\n.......\n} \n\n\/\/volatile\npublic class MyRunnable implements Runnable\n{\n    private volatile boolean active;\n    public void run()\n    {\n        active = true;\n        while (active) \/\/ \u7b2c\u4e00\u884c\n        {\n            \/\/ \u4ee3\u7801\n        }\n    }\n    public void stop()\n    {\n        active = false; \/\/ \u7b2c\u4e8c\u884c\n    }\n}<\/code><\/pre>\n<h2>\u8fd0\u7b97\u7b26\u4f18\u5148\u7ea7\uff08\u4ece\u9ad8\u5230\u4f4e\uff09\uff1a<\/h2>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='file:\/\/\/C:\/Users\/inex\/Pictures\/Typedown\/c4557228-bdcf-4081-9b1f-99e3099571ad.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"file:\/\/\/C:\/Users\/inex\/Pictures\/Typedown\/c4557228-bdcf-4081-9b1f-99e3099571ad.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"c4557228-bdcf-4081-9b1f-99e3099571ad\" \/><\/div><\/p>\n<h2>\u5faa\u73af\uff0c\u6761\u4ef6\u8bed\u53e5\uff0cswitch case\uff1a\u7565\uff08\u8ddfc\u4e00\u6837\uff0cwhile\uff0cdo while\u90a3\u4e9b\uff09<\/h2>\n<h2>Number &amp; Math \u7c7b\uff1a<\/h2>\n<h3>Number\u7c7b\uff1a<\/h3>\n<p>\u4e00\u822c\u5730\uff0c\u5f53\u9700\u8981\u4f7f\u7528\u6570\u5b57\u7684\u65f6\u5019\uff0c\u6211\u4eec\u901a\u5e38\u4f7f\u7528\u5185\u7f6e\u6570\u636e\u7c7b\u578b\uff0c\u5982\uff1a<strong>byte\u3001int\u3001long\u3001double<\/strong>\u00a0\u7b49\u3002\u4f46\u6211\u4eec\u5b9e\u9645\u5f00\u53d1\u5e38\u4f1a\u7528\u5230\u5bf9\u8c61\uff0cJava \u8bed\u8a00\u4e3a\u6bcf\u4e00\u4e2a\u5185\u7f6e\u6570\u636e\u7c7b\u578b\u63d0\u4f9b\u4e86\u5bf9\u5e94\u7684\u5305\u88c5\u7c7b\u3002\u6240\u6709\u7684\u5305\u88c5\u7c7b(Integer\u3001Long\u3001Byte\u3001Double\u3001Float\u3001Short)\u90fd\u662f\u62bd\u8c61\u7c7b Number \u7684\u5b50\u7c7b\u3002<code>Number<\/code> \u662f\u4e00\u4e2a\u62bd\u8c61\u57fa\u7c7b\uff08\u4e0d\u80fd\u76f4\u63a5\u5b9e\u4f8b\u5316\uff0c\u6240\u6709\u62bd\u8c61\u7c7b\u90fd\u4e0d\u80fd\uff09\uff0c\u7528\u4e8e\u7edf\u4e00\u6240\u6709\u6570\u503c\u7c7b\u578b\u7684\u516c\u5171\u884c\u4e3a\uff0c\u5b9e\u73b0\u201c\u591a\u6001\u201d\u548c\u201c\u6cdb\u5316\u7f16\u7a0b\u201d<\/p>\n<h4>\u5305\u88c5\u7c7b\u7684\u529f\u80fd\uff1a<\/h4>\n<ul>\n<li>\n<p>\u7528\u4e8e\u96c6\u5408\u548c\u6cdb\u578b<\/p>\n<\/li>\n<li>\n<p>\u652f\u6301 null \u503c<\/p>\n<\/li>\n<li>\n<p>\u63d0\u4f9b\u4e30\u5bcc\u7684\u5de5\u5177\u65b9\u6cd5<\/p>\n<\/li>\n<li>\n<p>\u652f\u6301\u53cd\u5c04\u548c\u6ce8\u91ca<\/p>\n<\/li>\n<li>\n<p>\u5b9e\u73b0\u591a\u6001\u548c\u7ee7\u627f<\/p>\n<\/li>\n<\/ul>\n<h4>\u7c7b\u578b\uff1a<\/h4>\n<table>\n<thead>\n<tr>\n<th>\u7c7b\u540d<\/th>\n<th>\u5bf9\u5e94\u57fa\u672c\u7c7b\u578b<\/th>\n<th>\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Byte<\/td>\n<td>byte<\/td>\n<td>\u5b57\u8282\u578b\u5305\u88c5\u7c7b<\/td>\n<\/tr>\n<tr>\n<td>Short<\/td>\n<td>short<\/td>\n<td>\u77ed\u6574\u578b\u5305\u88c5\u7c7b<\/td>\n<\/tr>\n<tr>\n<td>Integer<\/td>\n<td>int<\/td>\n<td>\u6574\u578b\u5305\u88c5\u7c7b<\/td>\n<\/tr>\n<tr>\n<td>Long<\/td>\n<td>long<\/td>\n<td>\u957f\u6574\u578b\u5305\u88c5\u7c7b<\/td>\n<\/tr>\n<tr>\n<td>Float<\/td>\n<td>float<\/td>\n<td>\u5355\u7cbe\u5ea6\u6d6e\u70b9\u578b\u5305\u88c5\u7c7b<\/td>\n<\/tr>\n<tr>\n<td>Double<\/td>\n<td>double<\/td>\n<td>\u53cc\u7cbe\u5ea6\u6d6e\u70b9\u578b\u5305\u88c5\u7c7b<\/td>\n<\/tr>\n<tr>\n<td>BigInteger<\/td>\n<td>&#8211;<\/td>\n<td>\u4e0d\u53ef\u53d8\u4efb\u610f\u7cbe\u5ea6\u6574\u6570<\/td>\n<\/tr>\n<tr>\n<td>BigDecimal<\/td>\n<td>&#8211;<\/td>\n<td>\u4e0d\u53ef\u53d8\u4efb\u610f\u7cbe\u5ea6\u6709\u7b26\u53f7\u5341\u8fdb\u5236\u6570<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h4>\u7edf\u4e00\u65b9\u6cd5\uff1a<\/h4>\n<h5>\u8f6c\u6362\u65b9\u6cd5\uff1a<\/h5>\n<p>\u5b9e\u73b0\uff1a<\/p>\n<pre><code>public abstract class Number implements Serializable {\n    \/\/ \u62bd\u8c61\u65b9\u6cd5\n    public abstract int intValue();\n    public abstract long longValue();\n    public abstract float floatValue();\n    public abstract double doubleValue();\n\n    \/\/ Java 8 \u65b0\u589e\n    public byte byteValue() {\n        return (byte)intValue();\n    }\n    public short shortValue() {\n        return (short)intValue();\n    }\n}<\/code><\/pre>\n<p>\u8fd9\u6837\u5f3a\u5236\u5404\u4e2a\u5b50\u7c7b\u5b9e\u73b0\u8f6c\u6362\u7684\u65b9\u6cd5<\/p>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>Number num = 1234.56; \/\/ \u5b9e\u9645\u662fDouble\u7c7b\u578b\n\nSystem.out.println(num.intValue());    \/\/ 1234 (\u622a\u65ad\u5c0f\u6570)\nSystem.out.println(num.longValue());   \/\/ 1234\nSystem.out.println(num.floatValue());  \/\/ 1234.56\nSystem.out.println(num.doubleValue()); \/\/ 1234.56<\/code><\/pre>\n<h5>\u81ea\u52a8\u88c5\u7bb1\u4e0e\u62c6\u7bb1\uff1a<\/h5>\n<p>\u5f53\u5185\u7f6e\u6570\u636e\u7c7b\u578b\u88ab\u5f53\u4f5c\u5bf9\u8c61\u4f7f\u7528\u7684\u65f6\u5019\uff0c\u7f16\u8bd1\u5668\u4f1a\u628a\u5185\u7f6e\u7c7b\u578b\u88c5\u7bb1\u4e3a\u5305\u88c5\u7c7b\u3002\u76f8\u4f3c\u7684\uff0c\u7f16\u8bd1\u5668\u4e5f\u53ef\u4ee5\u628a\u4e00\u4e2a\u5bf9\u8c61\u62c6\u7bb1\u4e3a\u5185\u7f6e\u7c7b\u578b\u3002\u8fd9\u4e2a\u8fc7\u7a0b\u662f\u81ea\u52a8\u7684<\/p>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>public class Test{\n    public static void main(String[] args){\n      Integer x = 5;\n      x =  x + 10;\n      System.out.println(x); \n   }\n} \n\/\/\u4ee5\u4e0a\u5b9e\u4f8b\u7f16\u8bd1\u8fd0\u884c\u7ed3\u679c\uff1a15<\/code><\/pre>\n<p>\u5f53 x \u88ab\u8d4b\u4e3a\u6574\u578b\u503c\u65f6\uff0c\u7531\u4e8ex\u662f\u4e00\u4e2a\u5bf9\u8c61\uff0c\u6240\u4ee5\u7f16\u8bd1\u5668\u8981\u5bf9x\u8fdb\u884c\u88c5\u7bb1\u3002\u7136\u540e\uff0c\u4e3a\u4e86\u4f7fx\u80fd\u8fdb\u884c\u52a0\u8fd0\u7b97\uff0c\u6240\u4ee5\u8981\u5bf9x\u8fdb\u884c\u62c6\u7bb1\u3002<\/p>\n<pre><code>\/\/ \u81ea\u52a8\u88c5\u7bb1\nInteger autoBoxed = 42; \/\/ \u7f16\u8bd1\u5668\u8f6c\u6362\u4e3a Integer.valueOf(42)\n\n\/\/ \u81ea\u52a8\u62c6\u7bb1\nint autoUnboxed = autoBoxed; \/\/ \u7f16\u8bd1\u5668\u8f6c\u6362\u4e3a autoBoxed.intVal<\/code><\/pre>\n<h5>\u6570\u503c\u6bd4\u8f83\uff1a<\/h5>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>java\nInteger x = 10;\nDouble y = 10.0;\n\n\/\/ \u6b63\u786e\u6bd4\u8f83\u65b9\u5f0f\uff1a\u8f6c\u6362\u4e3a\u540c\u4e00\u7c7b\u578b\u540e\u6bd4\u8f83\nSystem.out.println(x.doubleValue() == y.doubleValue()); \/\/ true<\/code><\/pre>\n<h5>\u5904\u7406\u5927\u6570\uff1a<\/h5>\n<pre><code>BigInteger bigInt = new BigInteger(\"12345678901234567890\");\nBigDecimal bigDec = new BigDecimal(\"1234567890.1234567890\");\n\n\/\/ \u5927\u6570\u8fd0\u7b97\nBigInteger sum = bigInt.add(new BigInteger(\"1\"));\nBigDecimal product = bigDec.multiply(new BigDecimal(\"2\"));<\/code><\/pre>\n<h5>\u6570\u503c\u683c\u5f0f\u5316\uff1a<\/h5>\n<pre><code>NumberFormat nf = NumberFormat.getInstance();\nnf.setMaximumFractionDigits(2);\n\nSystem.out.println(nf.format(1234.5678)); \/\/ \"1,234.57\"<\/code><\/pre>\n<h3>Math\u7c7b\uff1a<\/h3>\n<p>Math \u7c7b\u662f Java \u63d0\u4f9b\u7684\u6570\u5b66\u5de5\u5177\u7c7b\uff0c\u4f4d\u4e8e java.lang \u5305\u4e2d\uff0c\u5305\u542b\u6267\u884c\u57fa\u672c\u6570\u503c\u8fd0\u7b97\u7684\u9759\u6001\u65b9\u6cd5\u3002<\/p>\n<p>Java \u7684 Math \u5305\u542b\u4e86\u7528\u4e8e\u6267\u884c\u57fa\u672c\u6570\u5b66\u8fd0\u7b97\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\uff0c\u5982\u521d\u7b49\u6307\u6570\u3001\u5bf9\u6570\u3001\u5e73\u65b9\u6839\u548c\u4e09\u89d2\u51fd\u6570\u3002<\/p>\n<p>Math \u7684\u65b9\u6cd5\u90fd\u88ab\u5b9a\u4e49\u4e3a static \u5f62\u5f0f\uff0c\u901a\u8fc7 Math \u7c7b\u53ef\u4ee5\u5728\u4e3b\u51fd\u6570\u4e2d\u76f4\u63a5\u8c03\u7528\u3002<\/p>\n<h4>\u6b63\u4f59\u5f26\uff1a<\/h4>\n<pre><code>public class Test {  \n    public static void main (String []args)  \n    {  \n        System.out.println(\"90 \u5ea6\u7684\u6b63\u5f26\u503c\uff1a\" + Math.sin(Math.PI\/2));  \n        System.out.println(\"0\u5ea6\u7684\u4f59\u5f26\u503c\uff1a\" + Math.cos(0));  \n        System.out.println(\"60\u5ea6\u7684\u6b63\u5207\u503c\uff1a\" + Math.tan(Math.PI\/3));  \n        System.out.println(\"1\u7684\u53cd\u6b63\u5207\u503c\uff1a \" + Math.atan(1));  \n        System.out.println(\"\u03c0\/2\u7684\u89d2\u5ea6\u503c\uff1a\" + Math.toDegrees(Math.PI\/2));  \n        System.out.println(Math.PI);  \n    }  \n}<\/code><\/pre>\n<h4>\u6307\u6570\u5bf9\u6570\u8fd0\u7b97\uff1a<\/h4>\n<pre><code>Math.exp(1);    \/\/ e^1 \u2248 2.718\nMath.log(Math.E); \/\/ ln(e) = 1\nMath.log10(100); \/\/ log10(100) = 2<\/code><\/pre>\n<h4>\u968f\u673a\u6570\u751f\u6210\uff1a<\/h4>\n<pre><code>\/\/ \u751f\u6210[0.0, 1.0)\u4e4b\u95f4\u7684\u968f\u673a\u6570\ndouble random = Math.random(); \n\n\/\/ \u751f\u6210[1, 100]\u7684\u968f\u673a\u6574\u6570\nint randomInt = (int)(Math.random() * 100) + 1;<\/code><\/pre>\n<h4>\u5176\u4ed6\u8fd0\u7b97\uff1a<\/h4>\n<pre><code>Math.hypot(3, 4); \/\/ \u8ba1\u7b97sqrt(x\u00b2+y\u00b2) \u2192 5.0\nMath.IEEEremainder(10, 3); \/\/ IEEE\u4f59\u6570 \u2192 1.0<\/code><\/pre>\n<h4>\u5e38\u91cf\u5b57\u6bb5\uff1a<\/h4>\n<pre><code>Math.PI;    \/\/ \u03c0 \u2248 3.141592653589793\nMath.E;     \/\/ \u81ea\u7136\u5bf9\u6570\u5e95\u6570e \u2248 2.718281828459045<\/code><\/pre>\n<h3>Number &amp; Math \u7c7b\u65b9\u6cd5\uff1a<\/h3>\n<p>\u4e0b\u9762\u7684\u8868\u4e2d\u5217\u51fa\u7684\u662f Number &amp; Math \u7c7b\u5e38\u7528\u7684\u4e00\u4e9b\u65b9\u6cd5\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th>\u5e8f\u53f7<\/th>\n<th>\u65b9\u6cd5\u4e0e\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-xxxvalue.html\">xxxValue()<\/a>\u5c06 Number \u5bf9\u8c61\u8f6c\u6362\u4e3axxx\u6570\u636e\u7c7b\u578b\u7684\u503c\u5e76\u8fd4\u56de\u3002<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-compareto.html\">compareTo()<\/a>\u5c06number\u5bf9\u8c61\u4e0e\u53c2\u6570\u6bd4\u8f83\u3002<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-equals.html\">equals()<\/a>\u5224\u65adnumber\u5bf9\u8c61\u662f\u5426\u4e0e\u53c2\u6570\u76f8\u7b49\u3002<\/td>\n<\/tr>\n<tr>\n<td>4<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-valueof.html\">valueOf()<\/a>\u8fd4\u56de\u4e00\u4e2a Number \u5bf9\u8c61\u6307\u5b9a\u7684\u5185\u7f6e\u6570\u636e\u7c7b\u578b<\/td>\n<\/tr>\n<tr>\n<td>5<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-tostring.html\">toString()<\/a>\u4ee5\u5b57\u7b26\u4e32\u5f62\u5f0f\u8fd4\u56de\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>6<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-parseInt.html\">parseInt()<\/a>\u5c06\u5b57\u7b26\u4e32\u89e3\u6790\u4e3aint\u7c7b\u578b\u3002<\/td>\n<\/tr>\n<tr>\n<td>7<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-abs.html\">abs()<\/a>\u8fd4\u56de\u53c2\u6570\u7684\u7edd\u5bf9\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>8<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-ceil.html\">ceil()<\/a>\u8fd4\u56de\u5927\u4e8e\u7b49\u4e8e( &gt;= )\u7ed9\u5b9a\u53c2\u6570\u7684\u7684\u6700\u5c0f\u6574\u6570\uff0c\u7c7b\u578b\u4e3a\u53cc\u7cbe\u5ea6\u6d6e\u70b9\u578b\u3002<\/td>\n<\/tr>\n<tr>\n<td>9<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-floor.html\">floor()<\/a>\u8fd4\u56de\u5c0f\u4e8e\u7b49\u4e8e\uff08&lt;=\uff09\u7ed9\u5b9a\u53c2\u6570\u7684\u6700\u5927\u6574\u6570 \u3002<\/td>\n<\/tr>\n<tr>\n<td>10<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-rint.html\">rint()<\/a>\u8fd4\u56de\u4e0e\u53c2\u6570\u6700\u63a5\u8fd1\u7684\u6574\u6570\u3002\u8fd4\u56de\u7c7b\u578b\u4e3adouble\u3002<\/td>\n<\/tr>\n<tr>\n<td>11<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-round.html\">round()<\/a>\u5b83\u8868\u793a<strong>\u56db\u820d\u4e94\u5165<\/strong>\uff0c\u7b97\u6cd5\u4e3a\u00a0Math.floor(x+0.5)\uff0c\u5373\u5c06\u539f\u6765\u7684\u6570\u5b57\u52a0\u4e0a 0.5 \u540e\u518d\u5411\u4e0b\u53d6\u6574\uff0c\u6240\u4ee5\uff0cMath.round(11.5) \u7684\u7ed3\u679c\u4e3a12\uff0cMath.round(-11.5) \u7684\u7ed3\u679c\u4e3a-11\u3002<\/td>\n<\/tr>\n<tr>\n<td>12<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-min.html\">min()<\/a>\u8fd4\u56de\u4e24\u4e2a\u53c2\u6570\u4e2d\u7684\u6700\u5c0f\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>13<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-max.html\">max()<\/a>\u8fd4\u56de\u4e24\u4e2a\u53c2\u6570\u4e2d\u7684\u6700\u5927\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>14<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-exp.html\">exp()<\/a>\u8fd4\u56de\u81ea\u7136\u6570\u5e95\u6570e\u7684\u53c2\u6570\u6b21\u65b9\u3002<\/td>\n<\/tr>\n<tr>\n<td>15<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-log.html\">log()<\/a>\u8fd4\u56de\u53c2\u6570\u7684\u81ea\u7136\u6570\u5e95\u6570\u7684\u5bf9\u6570\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>16<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-pow.html\">pow()<\/a>\u8fd4\u56de\u7b2c\u4e00\u4e2a\u53c2\u6570\u7684\u7b2c\u4e8c\u4e2a\u53c2\u6570\u6b21\u65b9\u3002<\/td>\n<\/tr>\n<tr>\n<td>17<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-sqrt.html\">sqrt()<\/a>\u6c42\u53c2\u6570\u7684\u7b97\u672f\u5e73\u65b9\u6839\u3002<\/td>\n<\/tr>\n<tr>\n<td>18<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-sin.html\">sin()<\/a>\u6c42\u6307\u5b9adouble\u7c7b\u578b\u53c2\u6570\u7684\u6b63\u5f26\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>19<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-cos.html\">cos()<\/a>\u6c42\u6307\u5b9adouble\u7c7b\u578b\u53c2\u6570\u7684\u4f59\u5f26\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>20<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-tan.html\">tan()<\/a>\u6c42\u6307\u5b9adouble\u7c7b\u578b\u53c2\u6570\u7684\u6b63\u5207\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>21<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-asin.html\">asin()<\/a>\u6c42\u6307\u5b9adouble\u7c7b\u578b\u53c2\u6570\u7684\u53cd\u6b63\u5f26\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>22<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-acos.html\">acos()<\/a>\u6c42\u6307\u5b9adouble\u7c7b\u578b\u53c2\u6570\u7684\u53cd\u4f59\u5f26\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>23<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-atan.html\">atan()<\/a>\u6c42\u6307\u5b9adouble\u7c7b\u578b\u53c2\u6570\u7684\u53cd\u6b63\u5207\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>24<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-atan2.html\">atan2()<\/a>\u5c06\u7b1b\u5361\u5c14\u5750\u6807\u8f6c\u6362\u4e3a\u6781\u5750\u6807\uff0c\u5e76\u8fd4\u56de\u6781\u5750\u6807\u7684\u89d2\u5ea6\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>25<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-todegrees.html\">toDegrees()<\/a>\u5c06\u53c2\u6570\u8f6c\u5316\u4e3a\u89d2\u5ea6\u3002<\/td>\n<\/tr>\n<tr>\n<td>26<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-toradians.html\">toRadians()<\/a>\u5c06\u89d2\u5ea6\u8f6c\u6362\u4e3a\u5f27\u5ea6\u3002<\/td>\n<\/tr>\n<tr>\n<td>27<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/number-random.html\">random()<\/a>\u8fd4\u56de\u4e00\u4e2a\u968f\u673a\u6570\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Character \u7c7b\uff1a<\/h2>\n<p>Character \u7c7b\u7528\u4e8e\u5bf9\u5355\u4e2a\u5b57\u7b26\u8fdb\u884c\u64cd\u4f5c\u3002<\/p>\n<p>Character \u7c7b\u5728\u5bf9\u8c61\u4e2d\u5305\u88c5\u4e00\u4e2a\u57fa\u672c\u7c7b\u578b\u00a0<strong>char<\/strong>\u00a0\u7684\u503c<\/p>\n<p>char\u5b9e\u4f8b\uff1a<\/p>\n<pre><code>char ch = 'a';\n\n\/\/ Unicode \u5b57\u7b26\u8868\u793a\u5f62\u5f0f\nchar uniChar = 'u039A'; \n\n\/\/ \u5b57\u7b26\u6570\u7ec4\nchar[] charArray ={ 'a', 'b', 'c', 'd', 'e' };<\/code><\/pre>\n<p>\u7136\u800c\uff0c\u5728\u5b9e\u9645\u5f00\u53d1\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u7ecf\u5e38\u4f1a\u9047\u5230\u9700\u8981\u4f7f\u7528\u5bf9\u8c61\uff0c\u800c\u4e0d\u662f\u5185\u7f6e\u6570\u636e\u7c7b\u578b\u7684\u60c5\u51b5\u3002\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0cJava\u8bed\u8a00\u4e3a\u5185\u7f6e\u6570\u636e\u7c7b\u578bchar\u63d0\u4f9b\u4e86\u5305\u88c5\u7c7bCharacter\u7c7b\uff08\u5177\u4f53\u7c7b\uff09\u3002<\/p>\n<h3>\u81ea\u52a8\u88c5\u7bb1\u62c6\u7bb1\uff1a<\/h3>\n<pre><code>\/\/ \u539f\u59cb\u5b57\u7b26 'a' \u88c5\u7bb1\u5230 Character \u5bf9\u8c61 ch \u4e2d\nCharacter ch = 'a';\n\n\/\/ \u539f\u59cb\u5b57\u7b26 'x' \u7528 test \u65b9\u6cd5\u88c5\u7bb1\n\/\/ \u8fd4\u56de\u62c6\u7bb1\u7684\u503c\u5230 'c'\nchar c = test('x');<\/code><\/pre>\n<h3>\u7279\u6b8a\u8f6c\u4e49\u5b57\u7b26\uff1a<\/h3>\n<p>\u4e00\u4e9b\u5b57\u7b26\u8f6c\u4e49\u540e\u6709\u7279\u6b8a\u542b\u4e49\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th>\u8f6c\u4e49\u5e8f\u5217<\/th>\n<th>\u4f5c\u7528<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>t<\/td>\n<td>\u5728\u6587\u4e2d\u8be5\u5904\u63d2\u5165\u4e00\u4e2atab\u952e<\/td>\n<\/tr>\n<tr>\n<td>b<\/td>\n<td>\u5728\u6587\u4e2d\u8be5\u5904\u63d2\u5165\u4e00\u4e2a\u540e\u9000\u952e<\/td>\n<\/tr>\n<tr>\n<td>n<\/td>\n<td>\u5728\u6587\u4e2d\u8be5\u5904\u6362\u884c<\/td>\n<\/tr>\n<tr>\n<td>r<\/td>\n<td>\u5728\u6587\u4e2d\u8be5\u5904\u63d2\u5165\u56de\u8f66<\/td>\n<\/tr>\n<tr>\n<td>f<\/td>\n<td>\u5728\u6587\u4e2d\u8be5\u5904\u63d2\u5165\u6362\u9875\u7b26<\/td>\n<\/tr>\n<tr>\n<td>&#8216;<\/td>\n<td>\u5728\u6587\u4e2d\u8be5\u5904\u63d2\u5165\u5355\u5f15\u53f7<\/td>\n<\/tr>\n<tr>\n<td>&quot;<\/td>\n<td>\u5728\u6587\u4e2d\u8be5\u5904\u63d2\u5165\u53cc\u5f15\u53f7<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td>\u5728\u6587\u4e2d\u8be5\u5904\u63d2\u5165\u53cd\u659c\u6760<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>public class Test {\n\n   public static void main(String[] args) {\n      System.out.println(\"\u8bbf\u95ee\"\u83dc\u9e1f\u6559\u7a0b!\"\");\n   }\n}<\/code><\/pre>\n<h3>Character \u65b9\u6cd5\uff1a<\/h3>\n<table>\n<thead>\n<tr>\n<th>\u5e8f\u53f7<\/th>\n<th>\u65b9\u6cd5\u4e0e\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>isLetter():\u662f\u5426\u662f\u4e00\u4e2a\u5b57\u6bcd<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>isDigit():\u662f\u5426\u662f\u4e00\u4e2a\u6570\u5b57\u5b57\u7b26<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td>isWhitespace():\u662f\u5426\u662f\u4e00\u4e2a\u7a7a\u767d\u5b57\u7b26<\/td>\n<\/tr>\n<tr>\n<td>4<\/td>\n<td>isUpperCase():\u662f\u5426\u662f\u5927\u5199\u5b57\u6bcd<\/td>\n<\/tr>\n<tr>\n<td>5<\/td>\n<td>isLowerCase():\u662f\u5426\u662f\u5c0f\u5199\u5b57\u6bcd<\/td>\n<\/tr>\n<tr>\n<td>6<\/td>\n<td>toUpperCase():\u6307\u5b9a\u5b57\u6bcd\u7684\u5927\u5199\u5f62\u5f0f<\/td>\n<\/tr>\n<tr>\n<td>7<\/td>\n<td>toLowerCase():\u6307\u5b9a\u5b57\u6bcd\u7684\u5c0f\u5199\u5f62\u5f0f<\/td>\n<\/tr>\n<tr>\n<td>8<\/td>\n<td>toString():\u8fd4\u56de\u5b57\u7b26\u7684\u5b57\u7b26\u4e32\u5f62\u5f0f\uff0c\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u4ec5\u4e3a1<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>String \u7c7b:<\/h2>\n<p>\u5b57\u7b26\u4e32\u5e7f\u6cdb\u5e94\u7528 \u5728 Java \u7f16\u7a0b\u4e2d\uff0c\u5728 Java \u4e2d\u5b57\u7b26\u4e32\u5c5e\u4e8e\u5bf9\u8c61\uff0cJava \u63d0\u4f9b\u4e86 String \u7c7b\u6765\u521b\u5efa\u548c\u64cd\u4f5c\u5b57\u7b26\u4e32\u3002<\/p>\n<p>\u521b\u5efa\u5b57\u7b26\u4e32\u6700\u7b80\u5355\u7684\u65b9\u5f0f\u5982\u4e0b:<\/p>\n<pre><code>String str = \"Runoob\";<\/code><\/pre>\n<p>\u6216\u8005\u4e5f\u53ef\u4ee5\uff1a<\/p>\n<pre><code>String str2=new String(\"Runoob\");<\/code><\/pre>\n<p>String \u521b\u5efa\u7684\u5b57\u7b26\u4e32\u5b58\u50a8\u5728\u516c\u5171\u6c60\u4e2d\uff0c\u800c new \u521b\u5efa\u7684\u5b57\u7b26\u4e32\u5bf9\u8c61\u5728\u5806\u4e0a\uff0c\u6c60\u4f1a\u67e5\u91cd\u590d\u7528\uff0c\u5806\u4e0d\u4f1a\u3002<\/p>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='file:\/\/\/C:\/Users\/inex\/Pictures\/Typedown\/b9c220ce-db52-4abd-b733-cd8958c62509.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"file:\/\/\/C:\/Users\/inex\/Pictures\/Typedown\/b9c220ce-db52-4abd-b733-cd8958c62509.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"b9c220ce-db52-4abd-b733-cd8958c62509\" \/><\/div><\/p>\n<h3>\u83b7\u53d6\u5b57\u7b26\u4e32\u957f\u5ea6\uff1a<\/h3>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>public class StringDemo {\n    public static void main(String args[]) {\n        String site = \"www.runoob.com\";\n        int len = site.length();\n        System.out.println( \"\u83dc\u9e1f\u6559\u7a0b\u7f51\u5740\u957f\u5ea6 : \" + len );\n   }\n}<\/code><\/pre>\n<h3>\u8fde\u63a5\u5b57\u7b26\u4e32\uff1a<\/h3>\n<p>concat\u8fde\u63a5\uff08\u53ef\u4ee5\u7528\u4e8e\u5b57\u7b26\u4e32\u5e38\u91cf\uff09<\/p>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>\"\u6211\u7684\u540d\u5b57\u662f \".concat(\"Runoob\");\nstring1.concat(string2);<\/code><\/pre>\n<p>&#8216;+&#8217;\u8fd0\u7b97\u7b26\u8fde\u63a5\uff1a<\/p>\n<pre><code>\"Hello,\" + \" runoob\" + \"!\"\nSystem.out.println(\"1\u3001\" + string1 + \"www.runoob.com\"); <\/code><\/pre>\n<h3>\u683c\u5f0f\u5316\u5b57\u7b26\u4e32\uff1a<\/h3>\n<p>\u683c\u5f0f\u5316\u6570\u5b57\u53ef\u4ee5\u4f7f\u7528 printf() \u548c format() \u65b9\u6cd5<\/p>\n<p>printf()\u7528\u4e8e\u76f4\u63a5\u8f93\u51fa\u5230\u63a7\u5236\u53f0<\/p>\n<p>format()\u8fd4\u56de\u4e00\u4e2a\u683c\u5f0f\u5316\u7684\u5b57\u7b26\u4e32\u5bf9\u8c61<\/p>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>System.out.printf(\"\u6d6e\u70b9\u578b\u53d8\u91cf\u7684\u503c\u4e3a \" +\n                  \"%f, \u6574\u578b\u53d8\u91cf\u7684\u503c\u4e3a \" +\n                  \" %d, \u5b57\u7b26\u4e32\u53d8\u91cf\u7684\u503c\u4e3a \" +\n                  \"is %s\", floatVar, intVar, stringVar); \n\nString fs;\nfs = String.format(\"\u6d6e\u70b9\u578b\u53d8\u91cf\u7684\u503c\u4e3a \" +\n                   \"%f, \u6574\u578b\u53d8\u91cf\u7684\u503c\u4e3a \" +\n                   \" %d, \u5b57\u7b26\u4e32\u53d8\u91cf\u7684\u503c\u4e3a \" +\n                   \" %s\", floatVar, intVar, stringVar);<\/code><\/pre>\n<h3>String \u65b9\u6cd5\uff1a<\/h3>\n<table>\n<thead>\n<tr>\n<th>SN(\u5e8f\u53f7)<\/th>\n<th>\u65b9\u6cd5\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-charat.html\">char charAt(int index)<\/a><br \/>\u8fd4\u56de\u6307\u5b9a\u7d22\u5f15\u5904\u7684 char \u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-compareto.html\">int compareTo(Object o)<\/a><br \/>\u628a\u8fd9\u4e2a\u5b57\u7b26\u4e32\u548c\u53e6\u4e00\u4e2a\u5bf9\u8c61\u6bd4\u8f83\u3002<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-compareto.html\">int compareTo(String anotherString)<\/a><br \/>\u6309\u5b57\u5178\u987a\u5e8f\u6bd4\u8f83\u4e24\u4e2a\u5b57\u7b26\u4e32\u3002<\/td>\n<\/tr>\n<tr>\n<td>4<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-comparetoignorecase.html\">int compareToIgnoreCase(String str)<\/a><br \/>\u6309\u5b57\u5178\u987a\u5e8f\u6bd4\u8f83\u4e24\u4e2a\u5b57\u7b26\u4e32\uff0c\u4e0d\u8003\u8651\u5927\u5c0f\u5199\u3002<\/td>\n<\/tr>\n<tr>\n<td>5<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-concat.html\">String concat(String str)<\/a><br \/>\u5c06\u6307\u5b9a\u5b57\u7b26\u4e32\u8fde\u63a5\u5230\u6b64\u5b57\u7b26\u4e32\u7684\u7ed3\u5c3e\u3002<\/td>\n<\/tr>\n<tr>\n<td>6<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-contentequals.html\">boolean contentEquals(StringBuffer sb)<\/a><br \/>\u5f53\u4e14\u4ec5\u5f53\u5b57\u7b26\u4e32\u4e0e\u6307\u5b9a\u7684StringBuffer\u6709\u76f8\u540c\u987a\u5e8f\u7684\u5b57\u7b26\u65f6\u5019\u8fd4\u56de\u771f\u3002<\/td>\n<\/tr>\n<tr>\n<td>7<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-copyvalueof.html\">static String copyValueOf(char[] data)<\/a><br \/>\u8fd4\u56de\u6307\u5b9a\u6570\u7ec4\u4e2d\u8868\u793a\u8be5\u5b57\u7b26\u5e8f\u5217\u7684 String\u3002<\/td>\n<\/tr>\n<tr>\n<td>8<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-copyvalueof.html\">static String copyValueOf(char[] data, int offset, int count)<\/a><br \/>\u8fd4\u56de\u6307\u5b9a\u6570\u7ec4\u4e2d\u8868\u793a\u8be5\u5b57\u7b26\u5e8f\u5217\u7684 String\u3002<\/td>\n<\/tr>\n<tr>\n<td>9<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-endswith.html\">boolean endsWith(String suffix)<\/a><br \/>\u6d4b\u8bd5\u6b64\u5b57\u7b26\u4e32\u662f\u5426\u4ee5\u6307\u5b9a\u7684\u540e\u7f00\u7ed3\u675f\u3002<\/td>\n<\/tr>\n<tr>\n<td>10<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-equals.html\">boolean equals(Object anObject)<\/a><br \/>\u5c06\u6b64\u5b57\u7b26\u4e32\u4e0e\u6307\u5b9a\u7684\u5bf9\u8c61\u6bd4\u8f83\u3002<\/td>\n<\/tr>\n<tr>\n<td>11<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-equalsignorecase.html\">boolean equalsIgnoreCase(String anotherString)<\/a><br \/>\u5c06\u6b64 String \u4e0e\u53e6\u4e00\u4e2a String \u6bd4\u8f83\uff0c\u4e0d\u8003\u8651\u5927\u5c0f\u5199\u3002<\/td>\n<\/tr>\n<tr>\n<td>12<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-getbytes.html\">byte[] getBytes()<\/a><br \/>\u00a0\u4f7f\u7528\u5e73\u53f0\u7684\u9ed8\u8ba4\u5b57\u7b26\u96c6\u5c06\u6b64 String \u7f16\u7801\u4e3a byte \u5e8f\u5217\uff0c\u5e76\u5c06\u7ed3\u679c\u5b58\u50a8\u5230\u4e00\u4e2a\u65b0\u7684 byte \u6570\u7ec4\u4e2d\u3002<\/td>\n<\/tr>\n<tr>\n<td>13<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-getbytes.html\">byte[] getBytes(String charsetName)<\/a><br \/>\u4f7f\u7528\u6307\u5b9a\u7684\u5b57\u7b26\u96c6\u5c06\u6b64 String \u7f16\u7801\u4e3a byte \u5e8f\u5217\uff0c\u5e76\u5c06\u7ed3\u679c\u5b58\u50a8\u5230\u4e00\u4e2a\u65b0\u7684 byte \u6570\u7ec4\u4e2d\u3002<\/td>\n<\/tr>\n<tr>\n<td>14<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-getchars.html\">void getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)<\/a><br \/>\u5c06\u5b57\u7b26\u4ece\u6b64\u5b57\u7b26\u4e32\u590d\u5236\u5230\u76ee\u6807\u5b57\u7b26\u6570\u7ec4\u3002<\/td>\n<\/tr>\n<tr>\n<td>15<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-hashcode.html\">int hashCode()<\/a><br \/>\u8fd4\u56de\u6b64\u5b57\u7b26\u4e32\u7684\u54c8\u5e0c\u7801\u3002<\/td>\n<\/tr>\n<tr>\n<td>16<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-indexof.html\">int indexOf(int ch)<\/a><br \/>\u8fd4\u56de\u6307\u5b9a\u5b57\u7b26\u5728\u6b64\u5b57\u7b26\u4e32\u4e2d\u7b2c\u4e00\u6b21\u51fa\u73b0\u5904\u7684\u7d22\u5f15\u3002<\/td>\n<\/tr>\n<tr>\n<td>17<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-indexof.html\">int indexOf(int ch, int fromIndex)<\/a><br \/>\u8fd4\u56de\u5728\u6b64\u5b57\u7b26\u4e32\u4e2d\u7b2c\u4e00\u6b21\u51fa\u73b0\u6307\u5b9a\u5b57\u7b26\u5904\u7684\u7d22\u5f15\uff0c\u4ece\u6307\u5b9a\u7684\u7d22\u5f15\u5f00\u59cb\u641c\u7d22\u3002<\/td>\n<\/tr>\n<tr>\n<td>18<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-indexof.html\">int indexOf(String str)<\/a><br \/>\u00a0\u8fd4\u56de\u6307\u5b9a\u5b50\u5b57\u7b26\u4e32\u5728\u6b64\u5b57\u7b26\u4e32\u4e2d\u7b2c\u4e00\u6b21\u51fa\u73b0\u5904\u7684\u7d22\u5f15\u3002<\/td>\n<\/tr>\n<tr>\n<td>19<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-indexof.html\">int indexOf(String str, int fromIndex)<\/a><br \/>\u8fd4\u56de\u6307\u5b9a\u5b50\u5b57\u7b26\u4e32\u5728\u6b64\u5b57\u7b26\u4e32\u4e2d\u7b2c\u4e00\u6b21\u51fa\u73b0\u5904\u7684\u7d22\u5f15\uff0c\u4ece\u6307\u5b9a\u7684\u7d22\u5f15\u5f00\u59cb\u3002<\/td>\n<\/tr>\n<tr>\n<td>20<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-intern.html\">String intern()<\/a><br \/>\u00a0\u8fd4\u56de\u5b57\u7b26\u4e32\u5bf9\u8c61\u7684\u89c4\u8303\u5316\u8868\u793a\u5f62\u5f0f\u3002<\/td>\n<\/tr>\n<tr>\n<td>21<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-lastindexof.html\">int lastIndexOf(int ch)<\/a><br \/>\u00a0\u8fd4\u56de\u6307\u5b9a\u5b57\u7b26\u5728\u6b64\u5b57\u7b26\u4e32\u4e2d\u6700\u540e\u4e00\u6b21\u51fa\u73b0\u5904\u7684\u7d22\u5f15\u3002<\/td>\n<\/tr>\n<tr>\n<td>22<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-lastindexof.html\">int lastIndexOf(int ch, int fromIndex)<\/a><br \/>\u8fd4\u56de\u6307\u5b9a\u5b57\u7b26\u5728\u6b64\u5b57\u7b26\u4e32\u4e2d\u6700\u540e\u4e00\u6b21\u51fa\u73b0\u5904\u7684\u7d22\u5f15\uff0c\u4ece\u6307\u5b9a\u7684\u7d22\u5f15\u5904\u5f00\u59cb\u8fdb\u884c\u53cd\u5411\u641c\u7d22\u3002<\/td>\n<\/tr>\n<tr>\n<td>23<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-lastindexof.html\">int lastIndexOf(String str)<\/a><br \/>\u8fd4\u56de\u6307\u5b9a\u5b50\u5b57\u7b26\u4e32\u5728\u6b64\u5b57\u7b26\u4e32\u4e2d\u6700\u53f3\u8fb9\u51fa\u73b0\u5904\u7684\u7d22\u5f15\u3002<\/td>\n<\/tr>\n<tr>\n<td>24<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-lastindexof.html\">int lastIndexOf(String str, int fromIndex)<\/a><br \/>\u00a0\u8fd4\u56de\u6307\u5b9a\u5b50\u5b57\u7b26\u4e32\u5728\u6b64\u5b57\u7b26\u4e32\u4e2d\u6700\u540e\u4e00\u6b21\u51fa\u73b0\u5904\u7684\u7d22\u5f15\uff0c\u4ece\u6307\u5b9a\u7684\u7d22\u5f15\u5f00\u59cb\u53cd\u5411\u641c\u7d22\u3002<\/td>\n<\/tr>\n<tr>\n<td>25<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-length.html\">int length()<\/a><br \/>\u8fd4\u56de\u6b64\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u3002<\/td>\n<\/tr>\n<tr>\n<td>26<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-matches.html\">boolean matches(String regex)<\/a><br \/>\u544a\u77e5\u6b64\u5b57\u7b26\u4e32\u662f\u5426\u5339\u914d\u7ed9\u5b9a\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\u3002<\/td>\n<\/tr>\n<tr>\n<td>27<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-regionmatches.html\">boolean regionMatches(boolean ignoreCase, int toffset, String other, int ooffset, int len)<\/a><br \/>\u6d4b\u8bd5\u4e24\u4e2a\u5b57\u7b26\u4e32\u533a\u57df\u662f\u5426\u76f8\u7b49\u3002<\/td>\n<\/tr>\n<tr>\n<td>28<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-regionmatches.html\">boolean regionMatches(int toffset, String other, int ooffset, int len)<\/a><br \/>\u6d4b\u8bd5\u4e24\u4e2a\u5b57\u7b26\u4e32\u533a\u57df\u662f\u5426\u76f8\u7b49\u3002<\/td>\n<\/tr>\n<tr>\n<td>29<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-replace.html\">String replace(char oldChar, char newChar)<\/a><br \/>\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u4e32\uff0c\u5b83\u662f\u901a\u8fc7\u7528 newChar \u66ff\u6362\u6b64\u5b57\u7b26\u4e32\u4e2d\u51fa\u73b0\u7684\u6240\u6709 oldChar \u5f97\u5230\u7684\u3002<\/td>\n<\/tr>\n<tr>\n<td>30<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-replaceall.html\">String replaceAll(String regex, String replacement)<\/a><br \/>\u4f7f\u7528\u7ed9\u5b9a\u7684 replacement \u66ff\u6362\u6b64\u5b57\u7b26\u4e32\u6240\u6709\u5339\u914d\u7ed9\u5b9a\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u5b50\u5b57\u7b26\u4e32\u3002<\/td>\n<\/tr>\n<tr>\n<td>31<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-replacefirst.html\">String replaceFirst(String regex, String replacement)<\/a><br \/>\u00a0\u4f7f\u7528\u7ed9\u5b9a\u7684 replacement \u66ff\u6362\u6b64\u5b57\u7b26\u4e32\u5339\u914d\u7ed9\u5b9a\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u7b2c\u4e00\u4e2a\u5b50\u5b57\u7b26\u4e32\u3002<\/td>\n<\/tr>\n<tr>\n<td>32<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-split.html\">String[] split(String regex)<\/a><br \/>\u6839\u636e\u7ed9\u5b9a\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u5339\u914d\u62c6\u5206\u6b64\u5b57\u7b26\u4e32\u3002<\/td>\n<\/tr>\n<tr>\n<td>33<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-split.html\">String[] split(String regex, int limit)<\/a><br \/>\u6839\u636e\u5339\u914d\u7ed9\u5b9a\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\u6765\u62c6\u5206\u6b64\u5b57\u7b26\u4e32\u3002<\/td>\n<\/tr>\n<tr>\n<td>34<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-startswith.html\">boolean startsWith(String prefix)<\/a><br \/>\u6d4b\u8bd5\u6b64\u5b57\u7b26\u4e32\u662f\u5426\u4ee5\u6307\u5b9a\u7684\u524d\u7f00\u5f00\u59cb\u3002<\/td>\n<\/tr>\n<tr>\n<td>35<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-startswith.html\">boolean startsWith(String prefix, int toffset)<\/a><br \/>\u6d4b\u8bd5\u6b64\u5b57\u7b26\u4e32\u4ece\u6307\u5b9a\u7d22\u5f15\u5f00\u59cb\u7684\u5b50\u5b57\u7b26\u4e32\u662f\u5426\u4ee5\u6307\u5b9a\u524d\u7f00\u5f00\u59cb\u3002<\/td>\n<\/tr>\n<tr>\n<td>36<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-subsequence.html\">CharSequence subSequence(int beginIndex, int endIndex)<\/a><br \/>\u00a0\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u5e8f\u5217\uff0c\u5b83\u662f\u6b64\u5e8f\u5217\u7684\u4e00\u4e2a\u5b50\u5e8f\u5217\u3002<\/td>\n<\/tr>\n<tr>\n<td>37<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-substring.html\">String substring(int beginIndex)<\/a><br \/>\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u4e32\uff0c\u5b83\u662f\u6b64\u5b57\u7b26\u4e32\u7684\u4e00\u4e2a\u5b50\u5b57\u7b26\u4e32\u3002<\/td>\n<\/tr>\n<tr>\n<td>38<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-substring.html\">String substring(int beginIndex, int endIndex)<\/a><br \/>\u8fd4\u56de\u4e00\u4e2a\u65b0\u5b57\u7b26\u4e32\uff0c\u5b83\u662f\u6b64\u5b57\u7b26\u4e32\u7684\u4e00\u4e2a\u5b50\u5b57\u7b26\u4e32\u3002<\/td>\n<\/tr>\n<tr>\n<td>39<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-tochararray.html\">char[] toCharArray()<\/a><br \/>\u5c06\u6b64\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u6570\u7ec4\u3002<\/td>\n<\/tr>\n<tr>\n<td>40<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-tolowercase.html\">String toLowerCase()<\/a><br \/>\u4f7f\u7528\u9ed8\u8ba4\u8bed\u8a00\u73af\u5883\u7684\u89c4\u5219\u5c06\u6b64 String \u4e2d\u7684\u6240\u6709\u5b57\u7b26\u90fd\u8f6c\u6362\u4e3a\u5c0f\u5199\u3002<\/td>\n<\/tr>\n<tr>\n<td>41<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-tolowercase.html\">String toLowerCase(Locale locale)<\/a><br \/>\u00a0\u4f7f\u7528\u7ed9\u5b9a Locale \u7684\u89c4\u5219\u5c06\u6b64 String \u4e2d\u7684\u6240\u6709\u5b57\u7b26\u90fd\u8f6c\u6362\u4e3a\u5c0f\u5199\u3002<\/td>\n<\/tr>\n<tr>\n<td>42<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-tostring.html\">String toString()<\/a><br \/>\u00a0\u8fd4\u56de\u6b64\u5bf9\u8c61\u672c\u8eab\uff08\u5b83\u5df2\u7ecf\u662f\u4e00\u4e2a\u5b57\u7b26\u4e32\uff01\uff09\u3002<\/td>\n<\/tr>\n<tr>\n<td>43<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-touppercase.html\">String toUpperCase()<\/a><br \/>\u4f7f\u7528\u9ed8\u8ba4\u8bed\u8a00\u73af\u5883\u7684\u89c4\u5219\u5c06\u6b64 String \u4e2d\u7684\u6240\u6709\u5b57\u7b26\u90fd\u8f6c\u6362\u4e3a\u5927\u5199\u3002<\/td>\n<\/tr>\n<tr>\n<td>44<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-touppercase.html\">String toUpperCase(Locale locale)<\/a><br \/>\u4f7f\u7528\u7ed9\u5b9a Locale \u7684\u89c4\u5219\u5c06\u6b64 String \u4e2d\u7684\u6240\u6709\u5b57\u7b26\u90fd\u8f6c\u6362\u4e3a\u5927\u5199\u3002<\/td>\n<\/tr>\n<tr>\n<td>45<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-trim.html\">String trim()<\/a><br \/>\u8fd4\u56de\u5b57\u7b26\u4e32\u7684\u526f\u672c\uff0c\u5ffd\u7565\u524d\u5bfc\u7a7a\u767d\u548c\u5c3e\u90e8\u7a7a\u767d\u3002<\/td>\n<\/tr>\n<tr>\n<td>46<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-valueof.html\">static String valueOf(primitive data type x)<\/a><br \/>\u8fd4\u56de\u7ed9\u5b9adata type\u7c7b\u578bx\u53c2\u6570\u7684\u5b57\u7b26\u4e32\u8868\u793a\u5f62\u5f0f\u3002<\/td>\n<\/tr>\n<tr>\n<td>47<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-contains.html\">contains(CharSequence chars)<\/a><br \/>\u5224\u65ad\u662f\u5426\u5305\u542b\u6307\u5b9a\u7684\u5b57\u7b26\u7cfb\u5217\u3002<\/td>\n<\/tr>\n<tr>\n<td>48<\/td>\n<td><a href=\"https:\/\/www.runoob.com\/java\/java-string-isempty.html\">isEmpty()<\/a><br \/>\u5224\u65ad\u5b57\u7b26\u4e32\u662f\u5426\u4e3a\u7a7a\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Java StringBuffer \u548c StringBuilder \u7c7b:<\/h2>\n<p>\u5f53\u5bf9\u5b57\u7b26\u4e32\u8fdb\u884c\u4fee\u6539\u7684\u65f6\u5019\uff0c\u9700\u8981\u4f7f\u7528 StringBuffer \u548c StringBuilder \u7c7b\u3002<\/p>\n<p>\u548c String \u7c7b\u4e0d\u540c\u7684\u662f\uff0cStringBuffer \u548c StringBuilder \u7c7b\u7684\u5bf9\u8c61\u80fd\u591f\u88ab\u591a\u6b21\u7684\u4fee\u6539\uff0c\u5e76\u4e14\u4e0d\u4ea7\u751f\u65b0\u7684\u672a\u4f7f\u7528\u5bf9\u8c61\u3002<\/p>\n<p>\u5728\u4f7f\u7528 StringBuffer \u7c7b\u65f6\uff0c\u6bcf\u6b21\u90fd\u4f1a\u5bf9 StringBuffer \u5bf9\u8c61\u672c\u8eab\u8fdb\u884c\u64cd\u4f5c\uff0c\u800c\u4e0d\u662f\u751f\u6210\u65b0\u7684\u5bf9\u8c61\uff0c\u6240\u4ee5\u5982\u679c\u9700\u8981\u5bf9\u5b57\u7b26\u4e32\u8fdb\u884c\u4fee\u6539\u63a8\u8350\u4f7f\u7528 StringBuffer\u3002<\/p>\n<p>StringBuilder \u7c7b\u5728 Java 5 \u4e2d\u88ab\u63d0\u51fa\uff0c\u5b83\u548c StringBuffer \u4e4b\u95f4\u7684\u6700\u5927\u4e0d\u540c\u5728\u4e8e StringBuilder \u7684\u65b9\u6cd5\u4e0d\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff08\u4e0d\u80fd\u540c\u6b65\u8bbf\u95ee\uff09\u3002<\/p>\n<p>\u7531\u4e8e StringBuilder \u76f8\u8f83\u4e8e StringBuffer \u6709\u901f\u5ea6\u4f18\u52bf\uff0c\u6240\u4ee5\u591a\u6570\u60c5\u51b5\u4e0b\u5efa\u8bae\u4f7f\u7528 StringBuilder \u7c7b\u3002<\/p>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>public class RunoobTest{\n    public static void main(String[] args){\n        StringBuilder sb = new StringBuilder(10);\n        sb.append(\"Runoob..\");\n        System.out.println(sb);  \n        sb.append(\"!\");\n        System.out.println(sb); \n        sb.insert(8, \"Java\");\n        System.out.println(sb); \n        sb.delete(5,8);\n        System.out.println(sb);  \n    }\n}\n\/\/Runoob..\n\/\/Runoob..!\n\/\/Runoob..Java!\n\/\/RunooJava!\n\npublic class Test{\n  public static void main(String[] args){\n    StringBuffer sBuffer = new StringBuffer(\"\u83dc\u9e1f\u6559\u7a0b\u5b98\u7f51\uff1a\");\n    sBuffer.append(\"www\");\n    sBuffer.append(\".runoob\");\n    sBuffer.append(\".com\");\n    System.out.println(sBuffer);  \n  }\n} \n\/\/\u83dc\u9e1f\u6559\u7a0b\u5b98\u7f51\uff1awww.runoob.com<\/code><\/pre>\n<h3>StringBuffer \u65b9\u6cd5\uff1a<\/h3>\n<table>\n<thead>\n<tr>\n<th>1<\/th>\n<th>public StringBuffer append(String s)  <br \/>\u5c06\u6307\u5b9a\u7684\u5b57\u7b26\u4e32\u8ffd\u52a0\u5230\u6b64\u5b57\u7b26\u5e8f\u5217\u3002<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>2<\/td>\n<td>public StringBuffer reverse()<br \/>\u00a0\u5c06\u6b64\u5b57\u7b26\u5e8f\u5217\u7528\u5176\u53cd\u8f6c\u5f62\u5f0f\u53d6\u4ee3\u3002<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td>public delete(int start, int end)<br \/>\u79fb\u9664\u6b64\u5e8f\u5217\u7684\u5b50\u5b57\u7b26\u4e32\u4e2d\u7684\u5b57\u7b26\u3002<\/td>\n<\/tr>\n<tr>\n<td>4<\/td>\n<td>public insert(int offset, int i)<br \/>\u5c06\u00a0<code>int<\/code>\u00a0\u53c2\u6570\u7684\u5b57\u7b26\u4e32\u8868\u793a\u5f62\u5f0f\u63d2\u5165\u6b64\u5e8f\u5217\u4e2d\u3002<\/td>\n<\/tr>\n<tr>\n<td>5<\/td>\n<td>insert(int offset, String str)<br \/>\u5c06\u00a0<code>str<\/code>\u00a0\u53c2\u6570\u7684\u5b57\u7b26\u4e32\u63d2\u5165\u6b64\u5e8f\u5217\u4e2d\u3002<\/td>\n<\/tr>\n<tr>\n<td>6<\/td>\n<td>replace(int start, int end, String str)<br \/>\u4f7f\u7528\u7ed9\u5b9a\u00a0<code>String<\/code>\u00a0\u4e2d\u7684\u5b57\u7b26\u66ff\u6362\u6b64\u5e8f\u5217\u7684\u5b50\u5b57\u7b26\u4e32\u4e2d\u7684\u5b57\u7b26\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th>1<\/th>\n<th>int capacity()  <br \/>\u8fd4\u56de\u5f53\u524d\u5bb9\u91cf\u3002<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>2<\/td>\n<td>char charAt(int index)<br \/>\u8fd4\u56de\u6b64\u5e8f\u5217\u4e2d\u6307\u5b9a\u7d22\u5f15\u5904\u7684\u00a0<code>char<\/code>\u00a0\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td>void ensureCapacity(int minimumCapacity)<br \/>\u786e\u4fdd\u5bb9\u91cf\u81f3\u5c11\u7b49\u4e8e\u6307\u5b9a\u7684\u6700\u5c0f\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>4<\/td>\n<td>void getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)<br \/>\u5c06\u5b57\u7b26\u4ece\u6b64\u5e8f\u5217\u590d\u5236\u5230\u76ee\u6807\u5b57\u7b26\u6570\u7ec4\u00a0<code>dst<\/code>\u3002<\/td>\n<\/tr>\n<tr>\n<td>5<\/td>\n<td>int indexOf(String str)<br \/>\u8fd4\u56de\u7b2c\u4e00\u6b21\u51fa\u73b0\u7684\u6307\u5b9a\u5b50\u5b57\u7b26\u4e32\u5728\u8be5\u5b57\u7b26\u4e32\u4e2d\u7684\u7d22\u5f15\u3002<\/td>\n<\/tr>\n<tr>\n<td>6<\/td>\n<td>int indexOf(String str, int fromIndex)<br \/>\u4ece\u6307\u5b9a\u7684\u7d22\u5f15\u5904\u5f00\u59cb\uff0c\u8fd4\u56de\u7b2c\u4e00\u6b21\u51fa\u73b0\u7684\u6307\u5b9a\u5b50\u5b57\u7b26\u4e32\u5728\u8be5\u5b57\u7b26\u4e32\u4e2d\u7684\u7d22\u5f15\u3002<\/td>\n<\/tr>\n<tr>\n<td>7<\/td>\n<td>int lastIndexOf(String str)<br \/>\u8fd4\u56de\u6700\u53f3\u8fb9\u51fa\u73b0\u7684\u6307\u5b9a\u5b50\u5b57\u7b26\u4e32\u5728\u6b64\u5b57\u7b26\u4e32\u4e2d\u7684\u7d22\u5f15\u3002<\/td>\n<\/tr>\n<tr>\n<td>8<\/td>\n<td>int lastIndexOf(String str, int fromIndex)<br \/>\u8fd4\u56de String \u5bf9\u8c61\u4e2d\u5b50\u5b57\u7b26\u4e32\u6700\u540e\u51fa\u73b0\u7684\u4f4d\u7f6e\u3002<\/td>\n<\/tr>\n<tr>\n<td>9<\/td>\n<td>int length()<br \/>\u00a0\u8fd4\u56de\u957f\u5ea6\uff08\u5b57\u7b26\u6570\uff09\u3002<\/td>\n<\/tr>\n<tr>\n<td>10<\/td>\n<td>void setCharAt(int index, char ch)<br \/>\u5c06\u7ed9\u5b9a\u7d22\u5f15\u5904\u7684\u5b57\u7b26\u8bbe\u7f6e\u4e3a\u00a0<code>ch<\/code>\u3002<\/td>\n<\/tr>\n<tr>\n<td>11<\/td>\n<td>void setLength(int newLength)<br \/>\u8bbe\u7f6e\u5b57\u7b26\u5e8f\u5217\u7684\u957f\u5ea6\u3002<\/td>\n<\/tr>\n<tr>\n<td>12<\/td>\n<td>CharSequence subSequence(int start, int end)<br \/>\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u5e8f\u5217\uff0c\u8be5\u5b57\u7b26\u5e8f\u5217\u662f\u6b64\u5e8f\u5217\u7684\u5b50\u5e8f\u5217\u3002<\/td>\n<\/tr>\n<tr>\n<td>13<\/td>\n<td>String substring(int start)<br \/>\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u00a0<code>String<\/code>\uff0c\u5b83\u5305\u542b\u6b64\u5b57\u7b26\u5e8f\u5217\u5f53\u524d\u6240\u5305\u542b\u7684\u5b57\u7b26\u5b50\u5e8f\u5217\u3002<\/td>\n<\/tr>\n<tr>\n<td>14<\/td>\n<td>String substring(int start, int end)<br \/>\u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u00a0<code>String<\/code>\uff0c\u5b83\u5305\u542b\u6b64\u5e8f\u5217\u5f53\u524d\u6240\u5305\u542b\u7684\u5b57\u7b26\u5b50\u5e8f\u5217\u3002<\/td>\n<\/tr>\n<tr>\n<td>15<\/td>\n<td>String toString()<br \/>\u8fd4\u56de\u6b64\u5e8f\u5217\u4e2d\u6570\u636e\u7684\u5b57\u7b26\u4e32\u8868\u793a\u5f62\u5f0f\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>\u6570\u7ec4\uff1a<\/h2>\n<p>Java \u8bed\u8a00\u4e2d\u63d0\u4f9b\u7684\u6570\u7ec4\u662f\u7528\u6765\u5b58\u50a8\u56fa\u5b9a\u5927\u5c0f\u7684\u540c\u7c7b\u578b\u5143\u7d20<\/p>\n<p>\u9996\u5148\u5fc5\u987b\u58f0\u660e\u6570\u7ec4\u53d8\u91cf\uff0c\u624d\u80fd\u5728\u7a0b\u5e8f\u4e2d\u4f7f\u7528\u6570\u7ec4\u3002\u4e0b\u9762\u662f\u58f0\u660e\u6570\u7ec4\u53d8\u91cf\u7684\u8bed\u6cd5\uff1a<\/p>\n<pre><code>dataType[] arrayRefVar;   \/\/ \u9996\u9009\u7684\u65b9\u6cd5\n\u6216\ndataType arrayRefVar[];  \/\/ \u6548\u679c\u76f8\u540c\uff0c\u4f46\u4e0d\u662f\u9996\u9009\u65b9\u6cd5<\/code><\/pre>\n<p>\u521b\u5efa\u6570\u7ec4\uff1a<\/p>\n<pre><code>arrayRefVar = new dataType[arraySize];\n\/\/\u5148\u4f7f\u7528 dataType[arraySize] \u521b\u5efa\u4e86\u4e00\u4e2a\u6570\u7ec4\n\/\/\u518d\u628a\u65b0\u521b\u5efa\u7684\u6570\u7ec4\u7684\u5f15\u7528\u8d4b\u503c\u7ed9\u53d8\u91cf arrayRefVar<\/code><\/pre>\n<p>\u5408\u5728\u4e00\u8d77\u5b8c\u6210\uff1a<\/p>\n<pre><code>dataType[] arrayRefVar = new dataType[arraySize];<\/code><\/pre>\n<p>\u4e5f\u53ef\u4ee5\uff1a<\/p>\n<pre><code>dataType[] arrayRefVar = {value0, value1, ..., valuek};<\/code><\/pre>\n<h3>For-Each \u5faa\u73af\uff1a<\/h3>\n<p>JDK 1.5 \u5f15\u8fdb\u4e86\u4e00\u79cd\u65b0\u7684\u5faa\u73af\u7c7b\u578b\uff0c\u88ab\u79f0\u4e3a For-Each \u5faa\u73af\u6216\u8005\u52a0\u5f3a\u578b\u5faa\u73af\uff0c\u5b83\u80fd\u5728\u4e0d\u4f7f\u7528\u4e0b\u6807\u7684\u60c5\u51b5\u4e0b\u904d\u5386\u6570\u7ec4\u3002<\/p>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>public class TestArray {\n   public static void main(String[] args) {\n      double[] myList = {1.9, 2.9, 3.4, 3.5};\n\n      \/\/ \u6253\u5370\u6240\u6709\u6570\u7ec4\u5143\u7d20\n      for (double element: myList) {\n         System.out.println(element);\n      }\n   }\n}<\/code><\/pre>\n<h3>\u591a\u7ef4\u6570\u7ec4\uff1a<\/h3>\n<p>\u793a\u4f8b\uff1a<\/p>\n<pre><code>type[][] typeName = new type[typeLength1][typeLength2];<\/code><\/pre>\n<p>\u4e5f\u53ef\u4ee5\u4ece\u6700\u9ad8\u7ef4\u5f00\u59cb\uff0c\u5206\u522b\u4e3a\u6bcf\u4e00\u7ef4\u5206\u914d\u7a7a\u95f4\uff0c\u4f8b\u5982\uff1a<\/p>\n<pre><code>String[][] s = new String[2][];\ns[0] = new String[2];\ns[1] = new String[3];\ns[0][0] = new String(\"Good\");\ns[0][1] = new String(\"Luck\");\ns[1][0] = new String(\"to\");\ns[1][1] = new String(\"you\");\ns[1][2] = new String(\"!\");<\/code><\/pre>\n<h3>Arrays \u7c7b\uff1a<\/h3>\n<p>java.util.Arrays \u7c7b\u80fd\u65b9\u4fbf\u5730\u64cd\u4f5c\u6570\u7ec4\uff0c\u5b83\u63d0\u4f9b\u7684\u6240\u6709\u65b9\u6cd5\u90fd\u662f\u9759\u6001\u7684\u3002<\/p>\n<p>\u5177\u6709\u4ee5\u4e0b\u529f\u80fd\uff1a<\/p>\n<ul>\n<li>\u7ed9\u6570\u7ec4\u8d4b\u503c\uff1a\u901a\u8fc7 fill \u65b9\u6cd5\u3002<\/li>\n<li>\u5bf9\u6570\u7ec4\u6392\u5e8f\uff1a\u901a\u8fc7 sort \u65b9\u6cd5,\u6309\u5347\u5e8f\u3002<\/li>\n<li>\u6bd4\u8f83\u6570\u7ec4\uff1a\u901a\u8fc7 equals \u65b9\u6cd5\u6bd4\u8f83\u6570\u7ec4\u4e2d\u5143\u7d20\u503c\u662f\u5426\u76f8\u7b49\u3002<\/li>\n<li>\u67e5\u627e\u6570\u7ec4\u5143\u7d20\uff1a\u901a\u8fc7 binarySearch \u65b9\u6cd5\u80fd\u5bf9\u6392\u5e8f\u597d\u7684\u6570\u7ec4\u8fdb\u884c\u4e8c\u5206\u67e5\u627e\u6cd5\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n<p>\u5177\u4f53\u8bf4\u660e\u8bf7\u67e5\u770b\u4e0b\u8868\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th>\u5e8f\u53f7<\/th>\n<th>\u65b9\u6cd5\u548c\u8bf4\u660e<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td><strong>public static int binarySearch(Object[] a, Object key)<\/strong><br \/>\u7528\u4e8c\u5206\u67e5\u627e\u7b97\u6cd5\u5728\u7ed9\u5b9a\u6570\u7ec4\u4e2d\u641c\u7d22\u7ed9\u5b9a\u503c\u7684\u5bf9\u8c61(Byte,Int,double\u7b49)\u3002\u6570\u7ec4\u5728\u8c03\u7528\u524d\u5fc5\u987b\u6392\u5e8f\u597d\u7684\u3002\u5982\u679c\u67e5\u627e\u503c\u5305\u542b\u5728\u6570\u7ec4\u4e2d\uff0c\u5219\u8fd4\u56de\u641c\u7d22\u952e\u7684\u7d22\u5f15\uff1b\u5426\u5219\u8fd4\u56de (-(<em>\u63d2\u5165\u70b9<\/em>) &#8211; 1)\u3002<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td><strong>public static boolean equals(long[] a, long[] a2)<\/strong><br \/>\u5982\u679c\u4e24\u4e2a\u6307\u5b9a\u7684 long \u578b\u6570\u7ec4\u5f7c\u6b64\u76f8\u7b49\uff0c\u5219\u8fd4\u56de true\u3002\u5982\u679c\u4e24\u4e2a\u6570\u7ec4\u5305\u542b\u76f8\u540c\u6570\u91cf\u7684\u5143\u7d20\uff0c\u5e76\u4e14\u4e24\u4e2a\u6570\u7ec4\u4e2d\u7684\u6240\u6709\u76f8\u5e94\u5143\u7d20\u5bf9\u90fd\u662f\u76f8\u7b49\u7684\uff0c\u5219\u8ba4\u4e3a\u8fd9\u4e24\u4e2a\u6570\u7ec4\u662f\u76f8\u7b49\u7684\u3002\u6362\u53e5\u8bdd\u8bf4\uff0c\u5982\u679c\u4e24\u4e2a\u6570\u7ec4\u4ee5\u76f8\u540c\u987a\u5e8f\u5305\u542b\u76f8\u540c\u7684\u5143\u7d20\uff0c\u5219\u4e24\u4e2a\u6570\u7ec4\u662f\u76f8\u7b49\u7684\u3002\u540c\u6837\u7684\u65b9\u6cd5\u9002\u7528\u4e8e\u6240\u6709\u7684\u5176\u4ed6\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff08Byte\uff0cshort\uff0cInt\u7b49\uff09\u3002<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td><strong>public static void fill(int[] a, int val)<\/strong><br \/>\u5c06\u6307\u5b9a\u7684 int \u503c\u5206\u914d\u7ed9\u6307\u5b9a int \u578b\u6570\u7ec4\u6307\u5b9a\u8303\u56f4\u4e2d\u7684\u6bcf\u4e2a\u5143\u7d20\u3002\u540c\u6837\u7684\u65b9\u6cd5\u9002\u7528\u4e8e\u6240\u6709\u7684\u5176\u4ed6\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff08Byte\uff0cshort\uff0cInt\u7b49\uff09\u3002<\/td>\n<\/tr>\n<tr>\n<td>4<\/td>\n<td><strong>public static void sort(Object[] a)<\/strong><br \/>\u5bf9\u6307\u5b9a\u5bf9\u8c61\u6570\u7ec4\u6839\u636e\u5176\u5143\u7d20\u7684\u81ea\u7136\u987a\u5e8f\u8fdb\u884c\u5347\u5e8f\u6392\u5217\u3002\u540c\u6837\u7684\u65b9\u6cd5\u9002\u7528\u4e8e\u6240\u6709\u7684\u5176\u4ed6\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff08Byte\uff0cshort\uff0cInt\u7b49\uff09\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>\u6b63\u5219\uff1a<\/h2>\n<p>java.util.regex\u00a0\u5305\u662f Java \u6807\u51c6\u5e93\u4e2d\u7528\u4e8e\u652f\u6301\u6b63\u5219\u8868\u8fbe\u5f0f\u64cd\u4f5c\u7684\u5305\u3002<\/p>\n<p>java.util.regex \u5305\u4e3b\u8981\u5305\u62ec\u4ee5\u4e0b\u4e09\u4e2a\u7c7b\uff1a<\/p>\n<ul>\n<li>\n<p><strong><a href=\"https:\/\/www.runoob.com\/java\/java-regex-pattern.html\">Pattern \u7c7b<\/a>\uff1a<\/strong><br \/>\npattern \u5bf9\u8c61\u662f\u4e00\u4e2a\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u7f16\u8bd1\u8868\u793a\u3002Pattern \u7c7b\u6ca1\u6709\u516c\u5171\u6784\u9020\u65b9\u6cd5\u3002\u8981\u521b\u5efa\u4e00\u4e2a Pattern \u5bf9\u8c61\uff0c\u4f60\u5fc5\u987b\u9996\u5148\u8c03\u7528\u5176\u516c\u5171\u9759\u6001\u7f16\u8bd1\u65b9\u6cd5\uff0c\u5b83\u8fd4\u56de\u4e00\u4e2a Pattern \u5bf9\u8c61\u3002\u8be5\u65b9\u6cd5\u63a5\u53d7\u4e00\u4e2a\u6b63\u5219\u8868\u8fbe\u5f0f\u4f5c\u4e3a\u5b83\u7684\u7b2c\u4e00\u4e2a\u53c2\u6570\u3002<\/p>\n<\/li>\n<li>\n<p><strong><a href=\"https:\/\/www.runoob.com\/java\/java-regex-macher.html\">Matcher \u7c7b<\/a>\uff1a<\/strong><br \/>\nMatcher \u5bf9\u8c61\u662f\u5bf9\u8f93\u5165\u5b57\u7b26\u4e32\u8fdb\u884c\u89e3\u91ca\u548c\u5339\u914d\u64cd\u4f5c\u7684\u5f15\u64ce\u3002\u4e0ePattern \u7c7b\u4e00\u6837\uff0cMatcher \u4e5f\u6ca1\u6709\u516c\u5171\u6784\u9020\u65b9\u6cd5\u3002\u4f60\u9700\u8981\u8c03\u7528 Pattern \u5bf9\u8c61\u7684 matcher \u65b9\u6cd5\u6765\u83b7\u5f97\u4e00\u4e2a Matcher \u5bf9\u8c61\u3002<\/p>\n<\/li>\n<li>\n<p><strong>PatternSyntaxException\uff1a<\/strong><br \/>\nPatternSyntaxException \u662f\u4e00\u4e2a\u975e\u5f3a\u5236\u5f02\u5e38\u7c7b\uff0c\u5b83\u8868\u793a\u4e00\u4e2a\u6b63\u5219\u8868\u8fbe\u5f0f\u6a21\u5f0f\u4e2d\u7684\u8bed\u6cd5\u9519\u8bef\u3002<\/p>\n<\/li>\n<\/ul>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>import java.util.regex.*;\n\nclass RegexExample1{\n   public static void main(String[] args){\n      String content = \"I am noob \" +\n        \"from runoob.com.\";\n\n      String pattern = \".*runoob.*\";\n\n      boolean isMatch = Pattern.matches(pattern, content);\n      System.out.println(\"\u5b57\u7b26\u4e32\u4e2d\u662f\u5426\u5305\u542b\u4e86 'runoob' \u5b50\u5b57\u7b26\u4e32? \" + isMatch);\n   }\n}<\/code><\/pre>\n<h3>\u6355\u83b7\u7ec4\uff1a\u7565<\/h3>\n<h3>\u6b63\u5219\u8bed\u6cd5\uff1a<\/h3>\n<p>\u5728\u5176\u4ed6\u8bed\u8a00\u4e2d\uff0c<code>\\<\/code>\u00a0\u8868\u793a\uff1a<strong>\u6211\u60f3\u8981\u5728\u6b63\u5219\u8868\u8fbe\u5f0f\u4e2d\u63d2\u5165\u4e00\u4e2a\u666e\u901a\u7684\uff08\u5b57\u9762\u4e0a\u7684\uff09\u53cd\u659c\u6760\uff0c\u8bf7\u4e0d\u8981\u7ed9\u5b83\u4efb\u4f55\u7279\u6b8a\u7684\u610f\u4e49\u3002<\/strong><\/p>\n<p>\u5728 Java \u4e2d\uff0c<code>\\<\/code>\u8868\u793a\uff1a<strong>\u6211\u8981\u63d2\u5165\u4e00\u4e2a\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u53cd\u659c\u7ebf\uff0c\u6240\u4ee5\u5176\u540e\u7684\u5b57\u7b26\u5177\u6709\u7279\u6b8a\u7684\u610f\u4e49\u3002<\/strong><\/p>\n<p>java\u4e2d\u4e00\u4e2a<code><\/code>\u4ee3\u8868\u8f6c\u4e49,\u540c\u65f6\u5728\u6b63\u5219\u4e2d\u4f1a\u5148\u7ecf\u8fc7java\u7f16\u8bd1\u5668\u518d\u7ed9\u6b63\u5219\u5f15\u64ce\uff0c\u6240\u4ee5\u5982\u679c\u60f3\u8ba9\u6b63\u5219\u5f15\u64ce\u63a5\u6536\u5230<code>d<\/code>,\u5373\u4e00\u4e2a\u8f6c\u4e49\u7684d\uff0c\u9700\u8981\u5199<code>\\d<\/code>\uff0c\u7ecf\u8fc7java\u7f16\u8bd1\u5668\u540e\u4f1a\u8bc6\u522b\u4e00\u4e2a<code><\/code>\u4e3a\u8f6c\u4e49\u5b57\u7b26\u6240\u4ee5\u53d8\u6210<code>d<\/code>\u4f20\u9012\u7ed9\u6b63\u5219\u5f15\u64ce<\/p>\n<table>\n<thead>\n<tr>\n<th>\u5b57\u7b26<\/th>\n<th>\u8bf4\u660e<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><\/td>\n<td>\u5c06\u4e0b\u4e00\u5b57\u7b26\u6807\u8bb0\u4e3a\u7279\u6b8a\u5b57\u7b26\u3001\u6587\u672c\u3001\u53cd\u5411\u5f15\u7528\u6216\u516b\u8fdb\u5236\u8f6c\u4e49\u7b26\u3002\u4f8b\u5982\uff0c\u00a0n\u5339\u914d\u5b57\u7b26\u00a0n\u3002n\u00a0\u5339\u914d\u6362\u884c\u7b26\u3002\u5e8f\u5217\u00a0\\\u00a0\u5339\u914d\u00a0\u00a0\uff0c(\u00a0\u5339\u914d\u00a0(\u3002<\/td>\n<\/tr>\n<tr>\n<td>^<\/td>\n<td>\u5339\u914d\u8f93\u5165\u5b57\u7b26\u4e32\u5f00\u59cb\u7684\u4f4d\u7f6e\u3002\u5982\u679c\u8bbe\u7f6e\u4e86\u00a0<strong>RegExp<\/strong>\u00a0\u5bf9\u8c61\u7684\u00a0<strong>Multiline<\/strong>\u00a0\u5c5e\u6027\uff0c^ \u8fd8\u4f1a\u4e0e&quot;n&quot;\u6216&quot;r&quot;\u4e4b\u540e\u7684\u4f4d\u7f6e\u5339\u914d\u3002<\/td>\n<\/tr>\n<tr>\n<td>$<\/td>\n<td>\u5339\u914d\u8f93\u5165\u5b57\u7b26\u4e32\u7ed3\u5c3e\u7684\u4f4d\u7f6e\u3002\u5982\u679c\u8bbe\u7f6e\u4e86\u00a0<strong>RegExp<\/strong>\u00a0\u5bf9\u8c61\u7684\u00a0<strong>Multiline<\/strong>\u00a0\u5c5e\u6027\uff0c$ \u8fd8\u4f1a\u4e0e&quot;n&quot;\u6216&quot;r&quot;\u4e4b\u524d\u7684\u4f4d\u7f6e\u5339\u914d\u3002<\/td>\n<\/tr>\n<tr>\n<td>*<\/td>\n<td>\u96f6\u6b21\u6216\u591a\u6b21\u5339\u914d\u524d\u9762\u7684\u5b57\u7b26\u6216\u5b50\u8868\u8fbe\u5f0f\u3002\u4f8b\u5982\uff0czo<em> \u5339\u914d&quot;z&quot;\u548c&quot;zoo&quot;\u3002<\/em> \u7b49\u6548\u4e8e {0,}\u3002<\/td>\n<\/tr>\n<tr>\n<td>+<\/td>\n<td>\u4e00\u6b21\u6216\u591a\u6b21\u5339\u914d\u524d\u9762\u7684\u5b57\u7b26\u6216\u5b50\u8868\u8fbe\u5f0f\u3002\u4f8b\u5982\uff0c&quot;zo+&quot;\u4e0e&quot;zo&quot;\u548c&quot;zoo&quot;\u5339\u914d\uff0c\u4f46\u4e0e&quot;z&quot;\u4e0d\u5339\u914d\u3002+ \u7b49\u6548\u4e8e {1,}\u3002<\/td>\n<\/tr>\n<tr>\n<td>?<\/td>\n<td>\u96f6\u6b21\u6216\u4e00\u6b21\u5339\u914d\u524d\u9762\u7684\u5b57\u7b26\u6216\u5b50\u8868\u8fbe\u5f0f\u3002\u4f8b\u5982\uff0c&quot;do(es)?&quot;\u5339\u914d&quot;do&quot;\u6216&quot;does&quot;\u4e2d\u7684&quot;do&quot;\u3002? \u7b49\u6548\u4e8e {0,1}\u3002<\/td>\n<\/tr>\n<tr>\n<td>{<em>n<\/em>}<\/td>\n<td><em>n<\/em>\u00a0\u662f\u975e\u8d1f\u6574\u6570\u3002\u6b63\u597d\u5339\u914d\u00a0<em>n<\/em>\u00a0\u6b21\u3002\u4f8b\u5982\uff0c&quot;o{2}&quot;\u4e0e&quot;Bob&quot;\u4e2d\u7684&quot;o&quot;\u4e0d\u5339\u914d\uff0c\u4f46\u4e0e&quot;food&quot;\u4e2d\u7684\u4e24\u4e2a&quot;o&quot;\u5339\u914d\u3002<\/td>\n<\/tr>\n<tr>\n<td>{<em>n<\/em>,}<\/td>\n<td><em>n<\/em>\u00a0\u662f\u975e\u8d1f\u6574\u6570\u3002\u81f3\u5c11\u5339\u914d\u00a0<em>n<\/em>\u00a0\u6b21\u3002\u4f8b\u5982\uff0c&quot;o{2,}&quot;\u4e0d\u5339\u914d&quot;Bob&quot;\u4e2d\u7684&quot;o&quot;\uff0c\u800c\u5339\u914d&quot;foooood&quot;\u4e2d\u7684\u6240\u6709 o\u3002&quot;o{1,}&quot;\u7b49\u6548\u4e8e&quot;o+&quot;\u3002&quot;o{0,}&quot;\u7b49\u6548\u4e8e&quot;o*&quot;\u3002<\/td>\n<\/tr>\n<tr>\n<td>{<em>n<\/em>,<em>m<\/em>}<\/td>\n<td><em>m<\/em>\u00a0\u548c\u00a0<em>n<\/em>\u00a0\u662f\u975e\u8d1f\u6574\u6570\uff0c\u5176\u4e2d\u00a0<em>n<\/em>\u00a0&lt;=\u00a0<em>m<\/em>\u3002\u5339\u914d\u81f3\u5c11\u00a0<em>n<\/em>\u00a0\u6b21\uff0c\u81f3\u591a\u00a0<em>m<\/em>\u00a0\u6b21\u3002\u4f8b\u5982\uff0c&quot;o{1,3}&quot;\u5339\u914d&quot;fooooood&quot;\u4e2d\u7684\u5934\u4e09\u4e2a o\u3002&#8217;o{0,1}&#8217; \u7b49\u6548\u4e8e &#8216;o?&#8217;\u3002\u6ce8\u610f\uff1a\u60a8\u4e0d\u80fd\u5c06\u7a7a\u683c\u63d2\u5165\u9017\u53f7\u548c\u6570\u5b57\u4e4b\u95f4\u3002<\/td>\n<\/tr>\n<tr>\n<td>?<\/td>\n<td>\u5f53\u6b64\u5b57\u7b26\u7d27\u968f\u4efb\u4f55\u5176\u4ed6\u9650\u5b9a\u7b26\uff08*\u3001+\u3001?\u3001{<em>n<\/em>}\u3001{<em>n<\/em>,}\u3001{<em>n<\/em>,<em>m<\/em>}\uff09\u4e4b\u540e\u65f6\uff0c\u5339\u914d\u6a21\u5f0f\u662f&quot;\u975e\u8d2a\u5fc3\u7684&quot;\u3002&quot;\u975e\u8d2a\u5fc3\u7684&quot;\u6a21\u5f0f\u5339\u914d\u641c\u7d22\u5230\u7684\u3001\u5c3d\u53ef\u80fd\u77ed\u7684\u5b57\u7b26\u4e32\uff0c\u800c\u9ed8\u8ba4\u7684&quot;\u8d2a\u5fc3\u7684&quot;\u6a21\u5f0f\u5339\u914d\u641c\u7d22\u5230\u7684\u3001\u5c3d\u53ef\u80fd\u957f\u7684\u5b57\u7b26\u4e32\u3002\u4f8b\u5982\uff0c\u5728\u5b57\u7b26\u4e32&quot;oooo&quot;\u4e2d\uff0c&quot;o+?&quot;\u53ea\u5339\u914d\u5355\u4e2a&quot;o&quot;\uff0c\u800c&quot;o+&quot;\u5339\u914d\u6240\u6709&quot;o&quot;\u3002<\/td>\n<\/tr>\n<tr>\n<td>.<\/td>\n<td>\u5339\u914d\u9664&quot;rn&quot;\u4e4b\u5916\u7684\u4efb\u4f55\u5355\u4e2a\u5b57\u7b26\u3002\u82e5\u8981\u5339\u914d\u5305\u62ec&quot;rn&quot;\u5728\u5185\u7684\u4efb\u610f\u5b57\u7b26\uff0c\u8bf7\u4f7f\u7528\u8bf8\u5982&quot;[sS]&quot;\u4e4b\u7c7b\u7684\u6a21\u5f0f\u3002<\/td>\n<\/tr>\n<tr>\n<td>(<em>pattern<\/em>)<\/td>\n<td>\u5339\u914d\u00a0<em>pattern<\/em>\u00a0\u5e76\u6355\u83b7\u8be5\u5339\u914d\u7684\u5b50\u8868\u8fbe\u5f0f\u3002\u53ef\u4ee5\u4f7f\u7528\u00a0<strong>$0\u2026$9<\/strong>\u00a0\u5c5e\u6027\u4ece\u7ed3\u679c&quot;\u5339\u914d&quot;\u96c6\u5408\u4e2d\u68c0\u7d22\u6355\u83b7\u7684\u5339\u914d\u3002\u82e5\u8981\u5339\u914d\u62ec\u53f7\u5b57\u7b26 ( )\uff0c\u8bf7\u4f7f\u7528&quot;(&quot;\u6216\u8005&quot;)&quot;\u3002<\/td>\n<\/tr>\n<tr>\n<td>(?:<em>pattern<\/em>)<\/td>\n<td>\u5339\u914d\u00a0<em>pattern<\/em>\u00a0\u4f46\u4e0d\u6355\u83b7\u8be5\u5339\u914d\u7684\u5b50\u8868\u8fbe\u5f0f\uff0c\u5373\u5b83\u662f\u4e00\u4e2a\u975e\u6355\u83b7\u5339\u914d\uff0c\u4e0d\u5b58\u50a8\u4f9b\u4ee5\u540e\u4f7f\u7528\u7684\u5339\u914d\u3002\u8fd9\u5bf9\u4e8e\u7528&quot;or&quot;\u5b57\u7b26 (|) \u7ec4\u5408\u6a21\u5f0f\u90e8\u4ef6\u7684\u60c5\u51b5\u5f88\u6709\u7528\u3002\u4f8b\u5982\uff0c&#8217;industr(?:y|ies) \u662f\u6bd4 &#8216;industry|industries&#8217; \u66f4\u7ecf\u6d4e\u7684\u8868\u8fbe\u5f0f\u3002<\/td>\n<\/tr>\n<tr>\n<td>(?=<em>pattern<\/em>)<\/td>\n<td>\u6267\u884c\u6b63\u5411\u9884\u6d4b\u5148\u884c\u641c\u7d22\u7684\u5b50\u8868\u8fbe\u5f0f\uff0c\u8be5\u8868\u8fbe\u5f0f\u5339\u914d\u5904\u4e8e\u5339\u914d\u00a0<em>pattern<\/em>\u00a0\u7684\u5b57\u7b26\u4e32\u7684\u8d77\u59cb\u70b9\u7684\u5b57\u7b26\u4e32\u3002\u5b83\u662f\u4e00\u4e2a\u975e\u6355\u83b7\u5339\u914d\uff0c\u5373\u4e0d\u80fd\u6355\u83b7\u4f9b\u4ee5\u540e\u4f7f\u7528\u7684\u5339\u914d\u3002\u4f8b\u5982\uff0c&#8217;Windows (?=95|98|NT|2000)&#8217; \u5339\u914d&quot;Windows 2000&quot;\u4e2d\u7684&quot;Windows&quot;\uff0c\u4f46\u4e0d\u5339\u914d&quot;Windows 3.1&quot;\u4e2d\u7684&quot;Windows&quot;\u3002\u9884\u6d4b\u5148\u884c\u4e0d\u5360\u7528\u5b57\u7b26\uff0c\u5373\u53d1\u751f\u5339\u914d\u540e\uff0c\u4e0b\u4e00\u5339\u914d\u7684\u641c\u7d22\u7d27\u968f\u4e0a\u4e00\u5339\u914d\u4e4b\u540e\uff0c\u800c\u4e0d\u662f\u5728\u7ec4\u6210\u9884\u6d4b\u5148\u884c\u7684\u5b57\u7b26\u540e\u3002<\/td>\n<\/tr>\n<tr>\n<td>(?!<em>pattern<\/em>)<\/td>\n<td>\u6267\u884c\u53cd\u5411\u9884\u6d4b\u5148\u884c\u641c\u7d22\u7684\u5b50\u8868\u8fbe\u5f0f\uff0c\u8be5\u8868\u8fbe\u5f0f\u5339\u914d\u4e0d\u5904\u4e8e\u5339\u914d\u00a0<em>pattern<\/em>\u00a0\u7684\u5b57\u7b26\u4e32\u7684\u8d77\u59cb\u70b9\u7684\u641c\u7d22\u5b57\u7b26\u4e32\u3002\u5b83\u662f\u4e00\u4e2a\u975e\u6355\u83b7\u5339\u914d\uff0c\u5373\u4e0d\u80fd\u6355\u83b7\u4f9b\u4ee5\u540e\u4f7f\u7528\u7684\u5339\u914d\u3002\u4f8b\u5982\uff0c&#8217;Windows (?!95|98|NT|2000)&#8217; \u5339\u914d&quot;Windows 3.1&quot;\u4e2d\u7684 &quot;Windows&quot;\uff0c\u4f46\u4e0d\u5339\u914d&quot;Windows 2000&quot;\u4e2d\u7684&quot;Windows&quot;\u3002\u9884\u6d4b\u5148\u884c\u4e0d\u5360\u7528\u5b57\u7b26\uff0c\u5373\u53d1\u751f\u5339\u914d\u540e\uff0c\u4e0b\u4e00\u5339\u914d\u7684\u641c\u7d22\u7d27\u968f\u4e0a\u4e00\u5339\u914d\u4e4b\u540e\uff0c\u800c\u4e0d\u662f\u5728\u7ec4\u6210\u9884\u6d4b\u5148\u884c\u7684\u5b57\u7b26\u540e\u3002<\/td>\n<\/tr>\n<tr>\n<td>x|<em>y<\/em><\/td>\n<td>\u5339\u914d\u00a0<em>x<\/em>\u00a0\u6216\u00a0<em>y<\/em>\u3002\u4f8b\u5982\uff0c&#8217;z|food&#8217; \u5339\u914d&quot;z&quot;\u6216&quot;food&quot;\u3002'(z|f)ood&#8217; \u5339\u914d&quot;zood&quot;\u6216&quot;food&quot;\u3002<\/td>\n<\/tr>\n<tr>\n<td>[<em>xyz<\/em>]<\/td>\n<td>\u5b57\u7b26\u96c6\u3002\u5339\u914d\u5305\u542b\u7684\u4efb\u4e00\u5b57\u7b26\u3002\u4f8b\u5982\uff0c&quot;[abc]&quot;\u5339\u914d&quot;plain&quot;\u4e2d\u7684&quot;a&quot;\u3002<\/td>\n<\/tr>\n<tr>\n<td>[^<em>xyz<\/em>]<\/td>\n<td>\u53cd\u5411\u5b57\u7b26\u96c6\u3002\u5339\u914d\u672a\u5305\u542b\u7684\u4efb\u4f55\u5b57\u7b26\u3002\u4f8b\u5982\uff0c&quot;[^abc]&quot;\u5339\u914d&quot;plain&quot;\u4e2d&quot;p&quot;\uff0c&quot;l&quot;\uff0c&quot;i&quot;\uff0c&quot;n&quot;\u3002<\/td>\n<\/tr>\n<tr>\n<td>[<em>a-z<\/em>]<\/td>\n<td>\u5b57\u7b26\u8303\u56f4\u3002\u5339\u914d\u6307\u5b9a\u8303\u56f4\u5185\u7684\u4efb\u4f55\u5b57\u7b26\u3002\u4f8b\u5982\uff0c&quot;[a-z]&quot;\u5339\u914d&quot;a&quot;\u5230&quot;z&quot;\u8303\u56f4\u5185\u7684\u4efb\u4f55\u5c0f\u5199\u5b57\u6bcd\u3002<\/td>\n<\/tr>\n<tr>\n<td>[^<em>a-z<\/em>]<\/td>\n<td>\u53cd\u5411\u8303\u56f4\u5b57\u7b26\u3002\u5339\u914d\u4e0d\u5728\u6307\u5b9a\u7684\u8303\u56f4\u5185\u7684\u4efb\u4f55\u5b57\u7b26\u3002\u4f8b\u5982\uff0c&quot;[^a-z]&quot;\u5339\u914d\u4efb\u4f55\u4e0d\u5728&quot;a&quot;\u5230&quot;z&quot;\u8303\u56f4\u5185\u7684\u4efb\u4f55\u5b57\u7b26\u3002<\/td>\n<\/tr>\n<tr>\n<td>b<\/td>\n<td>\u5339\u914d\u4e00\u4e2a\u5b57\u8fb9\u754c\uff0c\u5373\u5b57\u4e0e\u7a7a\u683c\u95f4\u7684\u4f4d\u7f6e\u3002\u4f8b\u5982\uff0c&quot;erb&quot;\u5339\u914d&quot;never&quot;\u4e2d\u7684&quot;er&quot;\uff0c\u4f46\u4e0d\u5339\u914d&quot;verb&quot;\u4e2d\u7684&quot;er&quot;\u3002<\/td>\n<\/tr>\n<tr>\n<td>B<\/td>\n<td>\u975e\u5b57\u8fb9\u754c\u5339\u914d\u3002&quot;erB&quot;\u5339\u914d&quot;verb&quot;\u4e2d\u7684&quot;er&quot;\uff0c\u4f46\u4e0d\u5339\u914d&quot;never&quot;\u4e2d\u7684&quot;er&quot;\u3002<\/td>\n<\/tr>\n<tr>\n<td>cx<\/td>\n<td>\u5339\u914d\u00a0<em>x<\/em>\u00a0\u6307\u793a\u7684\u63a7\u5236\u5b57\u7b26\u3002\u4f8b\u5982\uff0ccM \u5339\u914d Control-M \u6216\u56de\u8f66\u7b26\u3002<em>x<\/em>\u00a0\u7684\u503c\u5fc5\u987b\u5728 A-Z \u6216 a-z \u4e4b\u95f4\u3002\u5982\u679c\u4e0d\u662f\u8fd9\u6837\uff0c\u5219\u5047\u5b9a c \u5c31\u662f&quot;c&quot;\u5b57\u7b26\u672c\u8eab\u3002<\/td>\n<\/tr>\n<tr>\n<td>d<\/td>\n<td>\u6570\u5b57\u5b57\u7b26\u5339\u914d\u3002\u7b49\u6548\u4e8e [0-9]\u3002<\/td>\n<\/tr>\n<tr>\n<td>D<\/td>\n<td>\u975e\u6570\u5b57\u5b57\u7b26\u5339\u914d\u3002\u7b49\u6548\u4e8e [^0-9]\u3002<\/td>\n<\/tr>\n<tr>\n<td>f<\/td>\n<td>\u6362\u9875\u7b26\u5339\u914d\u3002\u7b49\u6548\u4e8e x0c \u548c cL\u3002<\/td>\n<\/tr>\n<tr>\n<td>n<\/td>\n<td>\u6362\u884c\u7b26\u5339\u914d\u3002\u7b49\u6548\u4e8e x0a \u548c cJ\u3002<\/td>\n<\/tr>\n<tr>\n<td>r<\/td>\n<td>\u5339\u914d\u4e00\u4e2a\u56de\u8f66\u7b26\u3002\u7b49\u6548\u4e8e x0d \u548c cM\u3002<\/td>\n<\/tr>\n<tr>\n<td>s<\/td>\n<td>\u5339\u914d\u4efb\u4f55\u7a7a\u767d\u5b57\u7b26\uff0c\u5305\u62ec\u7a7a\u683c\u3001\u5236\u8868\u7b26\u3001\u6362\u9875\u7b26\u7b49\u3002\u4e0e [\u00a0fnrtv] \u7b49\u6548\u3002<\/td>\n<\/tr>\n<tr>\n<td>S<\/td>\n<td>\u5339\u914d\u4efb\u4f55\u975e\u7a7a\u767d\u5b57\u7b26\u3002\u4e0e [^\u00a0fnrtv] \u7b49\u6548\u3002<\/td>\n<\/tr>\n<tr>\n<td>t<\/td>\n<td>\u5236\u8868\u7b26\u5339\u914d\u3002\u4e0e x09 \u548c cI \u7b49\u6548\u3002<\/td>\n<\/tr>\n<tr>\n<td>v<\/td>\n<td>\u5782\u76f4\u5236\u8868\u7b26\u5339\u914d\u3002\u4e0e x0b \u548c cK \u7b49\u6548\u3002<\/td>\n<\/tr>\n<tr>\n<td>w<\/td>\n<td>\u5339\u914d\u4efb\u4f55\u5b57\u7c7b\u5b57\u7b26\uff0c\u5305\u62ec\u4e0b\u5212\u7ebf\u3002\u4e0e&quot;[A-Za-z0-9_]&quot;\u7b49\u6548\u3002<\/td>\n<\/tr>\n<tr>\n<td>W<\/td>\n<td>\u4e0e\u4efb\u4f55\u975e\u5355\u8bcd\u5b57\u7b26\u5339\u914d\u3002\u4e0e&quot;[^A-Za-z0-9_]&quot;\u7b49\u6548\u3002<\/td>\n<\/tr>\n<tr>\n<td>xn<\/td>\n<td>\u5339\u914d\u00a0<em>n<\/em>\uff0c\u6b64\u5904\u7684\u00a0<em>n<\/em>\u00a0\u662f\u4e00\u4e2a\u5341\u516d\u8fdb\u5236\u8f6c\u4e49\u7801\u3002\u5341\u516d\u8fdb\u5236\u8f6c\u4e49\u7801\u5fc5\u987b\u6b63\u597d\u662f\u4e24\u4f4d\u6570\u957f\u3002\u4f8b\u5982\uff0c&quot;x41&quot;\u5339\u914d&quot;A&quot;\u3002&quot;x041&quot;\u4e0e&quot;x04&quot;&amp;&quot;1&quot;\u7b49\u6548\u3002\u5141\u8bb8\u5728\u6b63\u5219\u8868\u8fbe\u5f0f\u4e2d\u4f7f\u7528 ASCII \u4ee3\u7801\u3002<\/td>\n<\/tr>\n<tr>\n<td>num<\/td>\n<td>\u5339\u914d\u00a0<em>num<\/em>\uff0c\u6b64\u5904\u7684\u00a0<em>num<\/em>\u00a0\u662f\u4e00\u4e2a\u6b63\u6574\u6570\u3002\u5230\u6355\u83b7\u5339\u914d\u7684\u53cd\u5411\u5f15\u7528\u3002\u4f8b\u5982\uff0c&quot;(.)1&quot;\u5339\u914d\u4e24\u4e2a\u8fde\u7eed\u7684\u76f8\u540c\u5b57\u7b26\u3002<\/td>\n<\/tr>\n<tr>\n<td>n<\/td>\n<td>\u6807\u8bc6\u4e00\u4e2a\u516b\u8fdb\u5236\u8f6c\u4e49\u7801\u6216\u53cd\u5411\u5f15\u7528\u3002\u5982\u679c _n_\u00a0\u524d\u9762\u81f3\u5c11\u6709\u00a0<em>n<\/em>\u00a0\u4e2a\u6355\u83b7\u5b50\u8868\u8fbe\u5f0f\uff0c\u90a3\u4e48\u00a0<em>n<\/em>\u00a0\u662f\u53cd\u5411\u5f15\u7528\u3002\u5426\u5219\uff0c\u5982\u679c\u00a0<em>n<\/em>\u00a0\u662f\u516b\u8fdb\u5236\u6570 (0-7)\uff0c\u90a3\u4e48\u00a0<em>n<\/em>\u00a0\u662f\u516b\u8fdb\u5236\u8f6c\u4e49\u7801\u3002<\/td>\n<\/tr>\n<tr>\n<td>nm<\/td>\n<td>\u6807\u8bc6\u4e00\u4e2a\u516b\u8fdb\u5236\u8f6c\u4e49\u7801\u6216\u53cd\u5411\u5f15\u7528\u3002\u5982\u679c _nm_\u00a0\u524d\u9762\u81f3\u5c11\u6709\u00a0<em>nm<\/em>\u00a0\u4e2a\u6355\u83b7\u5b50\u8868\u8fbe\u5f0f\uff0c\u90a3\u4e48\u00a0<em>nm<\/em>\u00a0\u662f\u53cd\u5411\u5f15\u7528\u3002\u5982\u679c _nm_\u00a0\u524d\u9762\u81f3\u5c11\u6709\u00a0<em>n<\/em>\u00a0\u4e2a\u6355\u83b7\uff0c\u5219\u00a0<em>n<\/em>\u00a0\u662f\u53cd\u5411\u5f15\u7528\uff0c\u540e\u9762\u8ddf\u6709\u5b57\u7b26\u00a0<em>m<\/em>\u3002\u5982\u679c\u4e24\u79cd\u524d\u9762\u7684\u60c5\u51b5\u90fd\u4e0d\u5b58\u5728\uff0c\u5219 _nm_\u00a0\u5339\u914d\u516b\u8fdb\u5236\u503c\u00a0<em>nm<\/em>\uff0c\u5176\u4e2d\u00a0<em>n<\/em>\u00a0\u548c\u00a0<em>m<\/em>\u00a0\u662f\u516b\u8fdb\u5236\u6570\u5b57 (0-7)\u3002<\/td>\n<\/tr>\n<tr>\n<td>nml<\/td>\n<td>\u5f53\u00a0<em>n<\/em>\u00a0\u662f\u516b\u8fdb\u5236\u6570 (0-3)\uff0c<em>m<\/em>\u00a0\u548c\u00a0<em>l<\/em>\u00a0\u662f\u516b\u8fdb\u5236\u6570 (0-7) \u65f6\uff0c\u5339\u914d\u516b\u8fdb\u5236\u8f6c\u4e49\u7801\u00a0<em>nml<\/em>\u3002<\/td>\n<\/tr>\n<tr>\n<td>un<\/td>\n<td>\u5339\u914d\u00a0<em>n<\/em>\uff0c\u5176\u4e2d\u00a0<em>n<\/em>\u00a0\u662f\u4ee5\u56db\u4f4d\u5341\u516d\u8fdb\u5236\u6570\u8868\u793a\u7684 Unicode \u5b57\u7b26\u3002\u4f8b\u5982\uff0cu00A9 \u5339\u914d\u7248\u6743\u7b26\u53f7 (\u00a9)\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>Matcher \u7c7b\u7684\u65b9\u6cd5:<\/h3>\n<h4>\u7d22\u5f15\u65b9\u6cd5:<\/h4>\n<table>\n<thead>\n<tr>\n<th><strong>\u5e8f\u53f7<\/strong><\/th>\n<th><strong>\u65b9\u6cd5\u53ca\u8bf4\u660e<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td>public int start()\u8fd4\u56de\u4ee5\u524d\u5339\u914d\u7684\u521d\u59cb\u7d22\u5f15\u3002<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>public int start(int group)\u00a0\u8fd4\u56de\u5728\u4ee5\u524d\u7684\u5339\u914d\u64cd\u4f5c\u671f\u95f4\uff0c\u7531\u7ed9\u5b9a\u7ec4\u6240\u6355\u83b7\u7684\u5b50\u5e8f\u5217\u7684\u521d\u59cb\u7d22\u5f15<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td>public int end()\u8fd4\u56de\u6700\u540e\u5339\u914d\u5b57\u7b26\u4e4b\u540e\u7684\u504f\u79fb\u91cf\u3002<\/td>\n<\/tr>\n<tr>\n<td>4<\/td>\n<td>public int end(int group)\u8fd4\u56de\u5728\u4ee5\u524d\u7684\u5339\u914d\u64cd\u4f5c\u671f\u95f4\uff0c\u7531\u7ed9\u5b9a\u7ec4\u6240\u6355\u83b7\u5b50\u5e8f\u5217\u7684\u6700\u540e\u5b57\u7b26\u4e4b\u540e\u7684\u504f\u79fb\u91cf\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u6ce8\uff1agroup(0)\u6307\u6574\u4e2a\u5339\u914d\u7684\u5b57\u7b26\u4e32<\/p>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>import java.util.regex.*;\n\npublic class MatcherPositionDemo1 {\n    public static void main(String[] args) {\n        String text = \"Hello runoob World\";\n        Pattern pattern = Pattern.compile(\"runoob\");\n        Matcher matcher = pattern.matcher(text);\n\n        if (matcher.find()) {\n            System.out.println(\"\u5339\u914d\u5185\u5bb9: \" + matcher.group());        \/\/ runoob\n            System.out.println(\"start(): \" + matcher.start());         \/\/ 6\n            System.out.println(\"end(): \" + matcher.end());             \/\/ 12\n            System.out.println(\"\u5339\u914d\u7247\u6bb5: \" + text.substring(matcher.start(), matcher.end())); \/\/ runoob\n        }\n    }\n}\n\npublic class MatcherPositionDemo2 {\n    public static void main(String[] args) {\n        String text = \"Email: user@example.com\";\n        \/\/ \u6355\u83b7\u7ec41: \u7528\u6237\u540d, \u6355\u83b7\u7ec42: \u57df\u540d\n        Pattern pattern = Pattern.compile(\"([a-z]+)@([a-z]+\\.com)\");\n        Matcher matcher = pattern.matcher(text);\n\n        if (matcher.find()) {\n            System.out.println(\"\u6574\u4e2a\u5339\u914d: \" + matcher.group(0));        \/\/ user@example.com\n            System.out.println(\"  start(0): \" + matcher.start(0) + \", end(0): \" + matcher.end(0)); \/\/ 7, 23\n\n            System.out.println(\"\u7ec41 (\u7528\u6237\u540d): \" + matcher.group(1));   \/\/ user\n            System.out.println(\"  start(1): \" + matcher.start(1) + \", end(1): \" + matcher.end(1)); \/\/ 7, 11\n\n            System.out.println(\"\u7ec42 (\u57df\u540d): \" + matcher.group(2));     \/\/ example.com\n            System.out.println(\"  start(2): \" + matcher.start(2) + \", end(2): \" + matcher.end(2)); \/\/ 12, 23\n        }\n    }\n}<\/code><\/pre>\n<h3>\u66ff\u6362\u65b9\u6cd5\uff1a<\/h3>\n<p>\u66ff\u6362\u65b9\u6cd5\u662f\u66ff\u6362\u8f93\u5165\u5b57\u7b26\u4e32\u91cc\u6587\u672c\u7684\u65b9\u6cd5\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th><strong>\u5e8f\u53f7<\/strong><\/th>\n<th><strong>\u65b9\u6cd5\u53ca\u8bf4\u660e<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td><strong>public Matcher appendReplacement(StringBuffer sb, String replacement)<\/strong><br \/>\u5b9e\u73b0\u975e\u7ec8\u7aef\u6dfb\u52a0\u548c\u66ff\u6362\u6b65\u9aa4\u3002<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td><strong>public StringBuffer appendTail(StringBuffer sb)<\/strong><br \/>\u5b9e\u73b0\u7ec8\u7aef\u6dfb\u52a0\u548c\u66ff\u6362\u6b65\u9aa4\u3002<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td><strong>public String replaceAll(String replacement)<\/strong><br \/>\u00a0\u66ff\u6362\u6a21\u5f0f\u4e0e\u7ed9\u5b9a\u66ff\u6362\u5b57\u7b26\u4e32\u76f8\u5339\u914d\u7684\u8f93\u5165\u5e8f\u5217\u7684\u6bcf\u4e2a\u5b50\u5e8f\u5217\u3002<\/td>\n<\/tr>\n<tr>\n<td>4<\/td>\n<td><strong>public String replaceFirst(String replacement)<\/strong><br \/>\u00a0\u66ff\u6362\u6a21\u5f0f\u4e0e\u7ed9\u5b9a\u66ff\u6362\u5b57\u7b26\u4e32\u5339\u914d\u7684\u8f93\u5165\u5e8f\u5217\u7684\u7b2c\u4e00\u4e2a\u5b50\u5e8f\u5217\u3002<\/td>\n<\/tr>\n<tr>\n<td>5<\/td>\n<td><strong>public static String quoteReplacement(String s)<\/strong><br \/>\u8fd4\u56de\u6307\u5b9a\u5b57\u7b26\u4e32\u7684\u5b57\u9762\u66ff\u6362\u5b57\u7b26\u4e32\u3002\u8fd9\u4e2a\u65b9\u6cd5\u8fd4\u56de\u4e00\u4e2a\u5b57\u7b26\u4e32\uff0c\u5c31\u50cf\u4f20\u9012\u7ed9Matcher\u7c7b\u7684appendReplacement \u65b9\u6cd5\u4e00\u4e2a\u5b57\u9762\u5b57\u7b26\u4e32\u4e00\u6837\u5de5\u4f5c\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>import java.util.regex.*;\n\npublic class SimpleReplaceDemo {\n    public static void main(String[] args) {\n        String text = \"Price: $99, Discount: $20\";\n\n        \/\/ \u66ff\u6362\u6240\u6709\u6570\u5b57\u4e3a [\u6570\u5b57]\n        String replacedAll = text.replaceAll(\"\\$(\\d+)\", \"[$1]\");\n        System.out.println(\"replaceAll: \" + replacedAll);\n        \/\/ \u8f93\u51fa: Price: [99], Discount: [20]\n\n        \/\/ \u4ec5\u66ff\u6362\u7b2c\u4e00\u4e2a\u4ef7\u683c\n        String replacedFirst = text.replaceFirst(\"\\$(\\d+)\", \"[$1]\");\n        System.out.println(\"replaceFirst: \" + replacedFirst);\n        \/\/ \u8f93\u51fa: Price: [99], Discount: $20\n    }\n} \n\/\/$1 \u662f\u53cd\u5411\u5f15\u7528\uff0c\u8868\u793a\u7b2c\u4e00\u4e2a\u6355\u83b7\u7ec4\u7684\u5185\u5bb9\uff08\u5373 d+ \u5339\u914d\u7684\u6570\u5b57\uff09\n\npublic class AdvancedReplaceDemo {\n    public static void main(String[] args) {\n        String text = \"ID: 1001, ID: 1002, ID: 1003\";\n        Pattern pattern = Pattern.compile(\"\\b(\\d{4})\\b\");\n        Matcher matcher = pattern.matcher(text);\n        StringBuffer result = new StringBuffer();\n        int count = 0;\n        while (matcher.find()) {\n            count++;\n            String masked = \"*\".repeat(matcher.group(1).length() - 1) + matcher.group(1).charAt(3);\n            matcher.appendReplacement(result,masked); \/\/ \u4fdd\u7559\u6700\u540e\u4e00\u4f4d\n        }\n        matcher.appendTail(result);\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/\u8fd9\u662f Matcher \u7c7b\u4e2d\u5b8c\u6210\u66ff\u6362\u6d41\u7a0b\u7684\u6700\u540e\u5173\u952e\u6b65\u9aa4\uff0c\u8d1f\u8d23\u5c06\u6700\u540e\u4e00\u6b21\u5339\u914d\u4e4b\u540e\u5269\u4f59\u7684\u672a\u5339\u914d\u6587\u672c\u8ffd\u52a0\u5230\u7ed3\u679c\u4e2d\u3002\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/\u5fc5\u987b\u5728 while (matcher.find()) \u5faa\u73af\u7ed3\u675f\u540e\u8c03\u7528\n        System.out.println(\"\u539f\u59cb: \" + text);\n        System.out.println(\"\u8131\u654f: \" + result.toString());\n        System.out.println(\"\u5171\u66ff\u6362 \" + count + \" \u5904\");\n    }\n}<\/code><\/pre>\n<h3>matches \u548c lookingAt \u65b9\u6cd5\uff1a<\/h3>\n<p>matches \u548c lookingAt \u65b9\u6cd5\u90fd\u7528\u6765\u5c1d\u8bd5\u5339\u914d\u4e00\u4e2a\u8f93\u5165\u5e8f\u5217\u6a21\u5f0f\u3002\u5b83\u4eec\u7684\u4e0d\u540c\u662f matches \u8981\u6c42\u6574\u4e2a\u5e8f\u5217\u90fd\u5339\u914d\uff0c\u800clookingAt \u4e0d\u8981\u6c42\u3002<\/p>\n<p>lookingAt \u65b9\u6cd5\u867d\u7136\u4e0d\u9700\u8981\u6574\u53e5\u90fd\u5339\u914d\uff0c\u4f46\u662f\u9700\u8981\u4ece\u7b2c\u4e00\u4e2a\u5b57\u7b26\u5f00\u59cb\u5339\u914d\u3002<\/p>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>import java.util.regex.Matcher;\nimport java.util.regex.Pattern;\n\npublic class RegexMatches\n{\n    private static final String REGEX = \"foo\";\n    private static final String INPUT = \"fooooooooooooooooo\";\n    private static final String INPUT2 = \"ooooofoooooooooooo\";\n    private static Pattern pattern;\n    private static Matcher matcher;\n    private static Matcher matcher2;\n\n    public static void main( String[] args ){\n       pattern = Pattern.compile(REGEX);\n       matcher = pattern.matcher(INPUT);\n       matcher2 = pattern.matcher(INPUT2);\n\n       System.out.println(\"Current REGEX is: \"+REGEX);\n       System.out.println(\"Current INPUT is: \"+INPUT);\n       System.out.println(\"Current INPUT2 is: \"+INPUT2);\n\n       System.out.println(\"lookingAt(): \"+matcher.lookingAt());\n       System.out.println(\"matches(): \"+matcher.matches());\n       System.out.println(\"lookingAt(): \"+matcher2.lookingAt());\n   }\n}<\/code><\/pre>\n<p>\u7ed3\u679c\uff1a<\/p>\n<pre><code>Current REGEX is: foo\nCurrent INPUT is: fooooooooooooooooo\nCurrent INPUT2 is: ooooofoooooooooooo\nlookingAt(): true\nmatches(): false\nlookingAt(): false<\/code><\/pre>\n<h3>replaceFirst \u548c replaceAll \u65b9\u6cd5\uff1a<\/h3>\n<p>replaceFirst \u548c replaceAll \u65b9\u6cd5\u7528\u6765\u66ff\u6362\u5339\u914d\u6b63\u5219\u8868\u8fbe\u5f0f\u7684\u6587\u672c\u3002\u4e0d\u540c\u7684\u662f\uff0creplaceFirst \u66ff\u6362\u9996\u6b21\u5339\u914d\uff0creplaceAll \u66ff\u6362\u6240\u6709\u5339\u914d\u3002\u524d\u9762\u7ed9\u4e86\u4f8b\u5b50\uff0c\u5c31\u4e0d\u518d\u7ed9\u4e86\u3002<\/p>\n<h3>appendReplacement \u548c appendTail \u65b9\u6cd5\uff1a<\/h3>\n<p>\u4e5f\u662f\u6587\u672c\u66ff\u6362\uff0c\u770b\u4e4b\u524d\u7684\u4f8b\u5b50\u5c31\u597d<\/p>\n<h3>PatternSyntaxException \u7c7b\u7684\u65b9\u6cd5\uff1a<\/h3>\n<p>PatternSyntaxException \u662f\u4e00\u4e2a\u975e\u5f3a\u5236\u5f02\u5e38\u7c7b\uff0c\u5b83\u6307\u793a\u4e00\u4e2a\u6b63\u5219\u8868\u8fbe\u5f0f\u6a21\u5f0f\u4e2d\u7684\u8bed\u6cd5\u9519\u8bef\u3002<\/p>\n<p>PatternSyntaxException \u7c7b\u63d0\u4f9b\u4e86\u4e0b\u9762\u7684\u65b9\u6cd5\u6765\u5e2e\u52a9\u6211\u4eec\u67e5\u770b\u53d1\u751f\u4e86\u4ec0\u4e48\u9519\u8bef\u3002<\/p>\n<table>\n<thead>\n<tr>\n<th><strong>\u5e8f\u53f7<\/strong><\/th>\n<th><strong>\u65b9\u6cd5\u53ca\u8bf4\u660e<\/strong><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1<\/td>\n<td><strong>public String getDescription()<\/strong><br \/>\u83b7\u53d6\u9519\u8bef\u7684\u63cf\u8ff0\u3002<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td><strong>public int getIndex()<\/strong><br \/>\u00a0\u83b7\u53d6\u9519\u8bef\u7684\u7d22\u5f15\u3002<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td><strong>public String getPattern()<\/strong><br \/>\u83b7\u53d6\u9519\u8bef\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\u6a21\u5f0f\u3002<\/td>\n<\/tr>\n<tr>\n<td>4<\/td>\n<td><strong>public String getMessage()<\/strong><br \/>\u8fd4\u56de\u591a\u884c\u5b57\u7b26\u4e32\uff0c\u5305\u542b\u8bed\u6cd5\u9519\u8bef\u53ca\u5176\u7d22\u5f15\u7684\u63cf\u8ff0\u3001\u9519\u8bef\u7684\u6b63\u5219\u8868\u8fbe\u5f0f\u6a21\u5f0f\u548c\u6a21\u5f0f\u4e2d\u9519\u8bef\u7d22\u5f15\u7684\u53ef\u89c6\u5316\u6307\u793a\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>import java.util.regex.*;\n\npublic class Demo {\n    public static void main(String[] args) {\n        try {\n            Pattern.compile(\"[a-\"); \/\/ \u6545\u610f\u5199\u9519\uff1a\u672a\u95ed\u5408\u5b57\u7b26\u7c7b\uff08\u7f3a\u5c11 ]\uff09\n        } catch (PatternSyntaxException e) {\n            \/\/ 1. \u9519\u8bef\u7c7b\u578b\u63cf\u8ff0\n            System.out.println(\"getDescription: \" + e.getDescription());\n            \/\/ 2. \u9519\u8bef\u4f4d\u7f6e\u7d22\u5f15\uff08\u4ece0\u5f00\u59cb\uff09\n            System.out.println(\"getIndex: \" + e.getIndex());\n            \/\/ 3. \u539f\u59cb\u9519\u8bef\u6b63\u5219\u8868\u8fbe\u5f0f\n            System.out.println(\"getPattern: \" + e.getPattern());\n            \/\/ 4. \u5b8c\u6574\u9519\u8bef\u62a5\u544a\uff08\u542b\u53ef\u89c6\u5316\u6307\u793a\uff09\n            System.out.println(\"getMessage:n\" + e.getMessage());\n        }\n    }\n}<\/code><\/pre>\n<h2>\u6784\u9020\u65b9\u6cd5\uff1a<\/h2>\n<p>\u53ea\u4e3e\u70b9\u4f8b\u5b50\uff0c\u4e4b\u524d\u5df2\u7ecf\u6709\u8fc7\u8bb2\u89e3<\/p>\n<pre><code>public class Person {\n    String name;\n    int age;\n\n    public Person() {\n        this.name = \"Unknown\";\n        this.age = 0;\n    }\n\n    public Person(String name) {\n        this.name = name;\n        this.age = 0;\n    }\n\n    public Person(String name, int age) {\n        this.name = name;\n        this.age = age;\n    }\n}<\/code><\/pre>\n<h3>this \u5173\u952e\u5b57\uff1a<\/h3>\n<p>1\u3001\u5f15\u7528\u5f53\u524d\u5bf9\u8c61\u7684\u5c5e\u6027\u6216\u65b9\u6cd5\uff1a\u5f53\u6784\u9020\u65b9\u6cd5\u7684\u53c2\u6570\u540d\u4e0e\u7c7b\u5c5e\u6027\u540d\u76f8\u540c\u65f6\uff0c\u4f7f\u7528 this \u6765\u533a\u5206\u7c7b\u5c5e\u6027\u548c\u53c2\u6570\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>public Person(String name, int age) {\n    this.name = name; \/\/ this.name \u8868\u793a\u7c7b\u7684\u5c5e\u6027\n    this.age = age;\n}<\/code><\/pre>\n<p>2\u3001\u8c03\u7528\u53e6\u4e00\u4e2a\u6784\u9020\u65b9\u6cd5\uff1a\u53ef\u4ee5\u4f7f\u7528 this() \u8c03\u7528\u5f53\u524d\u7c7b\u7684\u5176\u4ed6\u6784\u9020\u65b9\u6cd5\uff0c\u5e38\u7528\u4e8e\u907f\u514d\u91cd\u590d\u4ee3\u7801\uff0c\u4f46\u5fc5\u987b\u653e\u5728\u6784\u9020\u65b9\u6cd5\u7684\u7b2c\u4e00\u884c\u3002<\/p>\n<pre><code>public Person(String name) {\n    this(name, 0); \/\/ \u8c03\u7528\u53e6\u4e00\u4e2a\u53cc\u53c2\u6570\u7684\u6784\u9020\u65b9\u6cd5\n}\n\npublic Person(String name, int age) {\n    this.name = name;\n    this.age = age;\n}<\/code><\/pre>\n<h2>Java \u4e2d\u7684\u6d41\uff08Stream\uff09\u3001\u6587\u4ef6\uff08File\uff09\u548c IO\uff08\u8f93\u5165\u8f93\u51fa\uff09\uff1a<\/h2>\n<h3>\u8bfb\u53d6\u63a7\u5236\u53f0\u8f93\u5165\uff1a<\/h3>\n<p>Java \u7684\u63a7\u5236\u53f0\u8f93\u5165\u7531 System.in \u5b8c\u6210\u3002<\/p>\n<p>\u4e3a\u4e86\u83b7\u5f97\u4e00\u4e2a\u7ed1\u5b9a\u5230\u63a7\u5236\u53f0\u7684\u5b57\u7b26\u6d41\uff0c\u4f60\u53ef\u4ee5\u628a System.in \u5305\u88c5\u5728\u4e00\u4e2a BufferedReader \u5bf9\u8c61\u4e2d\u6765\u521b\u5efa\u4e00\u4e2a\u5b57\u7b26\u6d41\u3002<\/p>\n<p>\u4e0b\u9762\u662f\u521b\u5efa BufferedReader \u7684\u57fa\u672c\u8bed\u6cd5\uff1a<\/p>\n<pre><code>BufferedReader br = new BufferedReader(new \n                      InputStreamReader(System.in));<\/code><\/pre>\n<p>\u4ece BufferedReader \u5bf9\u8c61\u8bfb\u53d6\u4e00\u4e2a\u5b57\u7b26\u8981\u4f7f\u7528 read() \u65b9\u6cd5\uff0c\u6bcf\u6b21\u8c03\u7528 read() \u65b9\u6cd5\uff0c\u5b83\u4ece\u8f93\u5165\u6d41\u8bfb\u53d6\u4e00\u4e2a\u5b57\u7b26\u5e76\u628a\u8be5\u5b57\u7b26\u4f5c\u4e3a\u6574\u6570\u503c\u8fd4\u56de\u3002 \u5f53\u6d41\u7ed3\u675f\u7684\u65f6\u5019\u8fd4\u56de -1\u3002\u8be5\u65b9\u6cd5\u629b\u51fa IOException\u3002<\/p>\n<p>\u4e0b\u9762\u7684\u7a0b\u5e8f\u793a\u8303\u4e86\u7528 read() \u65b9\u6cd5\u4ece\u63a7\u5236\u53f0\u4e0d\u65ad\u8bfb\u53d6\u5b57\u7b26\u76f4\u5230\u7528\u6237\u8f93\u5165\u00a0q\uff1a<\/p>\n<pre><code>\/\/\u4f7f\u7528 BufferedReader \u5728\u63a7\u5236\u53f0\u8bfb\u53d6\u5b57\u7b26\n\nimport java.io.*;\n\npublic class BRRead {\n    public static void main(String[] args) throws IOException {\n        char c;\n        \/\/ \u4f7f\u7528 System.in \u521b\u5efa BufferedReader\n        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));\n        System.out.println(\"\u8f93\u5165\u5b57\u7b26, \u6309\u4e0b 'q' \u952e\u9000\u51fa\u3002\");\n        \/\/ \u8bfb\u53d6\u5b57\u7b26\n        do {\n            c = (char) br.read();\n            System.out.println(c);\n        } while (c != 'q');\n    }\n}<\/code><\/pre>\n<p>\u8bfb\u53d6\u5b57\u7b26\u4e32\uff1a<\/p>\n<p>\u4f7f\u7528 BufferedReader \u7684 readLine() \u65b9\u6cd5<\/p>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>\/\/\u4f7f\u7528 BufferedReader \u5728\u63a7\u5236\u53f0\u8bfb\u53d6\u5b57\u7b26\nimport java.io.*;\n\npublic class BRReadLines {\n    public static void main(String[] args) throws IOException {\n        \/\/ \u4f7f\u7528 System.in \u521b\u5efa BufferedReader\n        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));\n        String str;\n        System.out.println(\"Enter lines of text.\");\n        System.out.println(\"Enter 'end' to quit.\");\n        do {\n            str = br.readLine();\n            System.out.println(str);\n        } while (!str.equals(\"end\"));\n    }\n}<\/code><\/pre>\n<h3>\u63a7\u5236\u53f0\u8f93\u51fa\uff1a<\/h3>\n<p>\u4f7f\u7528println()\u6216print()\u5b8c\u6210\uff0c\u524d\u8005\u4f1a\u5728\u6253\u5370\u7ed3\u675f\u540e\u591a\u4e00\u4e2a\u6362\u884c\u7b26\uff0c\u540e\u8005\u4e0d\u4f1a\uff0c\u6216\u8005write()\u4e5f\u884c\uff0c\u4f46\u662f\u4e0d\u5e38\u7528<\/p>\n<p>write()\u4f8b\uff1a<\/p>\n<pre><code>\/\/\u4f7f\u7528 BufferedReader \u5728\u63a7\u5236\u53f0\u8bfb\u53d6\u5b57\u7b26\nimport java.io.*;\n\npublic class BRReadLines {\n    public static void main(String[] args) throws IOException {\n        \/\/ \u4f7f\u7528 System.in \u521b\u5efa BufferedReader\n        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));\n        String str;\n        System.out.println(\"Enter lines of text.\");\n        System.out.println(\"Enter 'end' to quit.\");\n        do {\n            str = br.readLine();\n            System.out.println(str);\n        } while (!str.equals(\"end\"));\n    }\n}<\/code><\/pre>\n<h3>\u8f93\u5165\u8f93\u51fa\u6d41\uff1a<\/h3>\n<p>java\u4e2d\u8f93\u5165\u6d41\uff08input\uff09\u7528\u4e8e\u8bfb\u53d6\u6570\u636e\uff0c\u8f93\u51fa\u6d41\uff08output\uff09\u7528\u4e8e\u8f93\u51fa\u6570\u636e\uff0c\u540c\u65f6\u6709\u5b57\u7b26\u6d41\uff08 \u5904\u7406\u6587\u672c\u6570\u636e\uff09\u4e0e\u5b57\u8282\u6d41\uff08 \u5904\u7406\u4e8c\u8fdb\u5236\u6570\u636e\uff09\u7684\u533a\u522b\uff0c<\/p>\n<p>\u4e0b\u9762\u662f\u7c7b\u8868<\/p>\n<table>\n<thead>\n<tr>\n<th>\u7c7b\u540d<\/th>\n<th>\u7c7b\u578b<\/th>\n<th>\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><code>InputStream<\/code><\/td>\n<td>\u62bd\u8c61\u7c7b (\u8f93\u5165\u6d41)<\/td>\n<td>\u6240\u6709\u5b57\u8282\u8f93\u5165\u6d41\u7684\u8d85\u7c7b\uff0c\u5904\u7406\u5b57\u8282\u7684\u8f93\u5165\u64cd\u4f5c\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>OutputStream<\/code><\/td>\n<td>\u62bd\u8c61\u7c7b (\u8f93\u51fa\u6d41)<\/td>\n<td>\u6240\u6709\u5b57\u8282\u8f93\u51fa\u6d41\u7684\u8d85\u7c7b\uff0c\u5904\u7406\u5b57\u8282\u7684\u8f93\u51fa\u64cd\u4f5c\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>FileInputStream<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u4ece\u6587\u4ef6\u4e2d\u8bfb\u53d6\u5b57\u8282\u6570\u636e\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>FileOutputStream<\/code><\/td>\n<td>\u8f93\u51fa\u6d41<\/td>\n<td>\u5c06\u5b57\u8282\u6570\u636e\u5199\u5165\u6587\u4ef6\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>BufferedInputStream<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u4e3a\u5b57\u8282\u8f93\u5165\u6d41\u63d0\u4f9b\u7f13\u51b2\u529f\u80fd\uff0c\u63d0\u9ad8\u8bfb\u53d6\u6548\u7387\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>BufferedOutputStream<\/code><\/td>\n<td>\u8f93\u51fa\u6d41<\/td>\n<td>\u4e3a\u5b57\u8282\u8f93\u51fa\u6d41\u63d0\u4f9b\u7f13\u51b2\u529f\u80fd\uff0c\u63d0\u9ad8\u5199\u5165\u6548\u7387\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>ByteArrayInputStream<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u5c06\u5185\u5b58\u4e2d\u7684\u5b57\u8282\u6570\u7ec4\u4f5c\u4e3a\u8f93\u5165\u6e90\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>ByteArrayOutputStream<\/code><\/td>\n<td>\u8f93\u51fa\u6d41<\/td>\n<td>\u5c06\u6570\u636e\u5199\u5165\u5230\u5185\u5b58\u4e2d\u7684\u5b57\u8282\u6570\u7ec4\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>DataInputStream<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u5141\u8bb8\u4ece\u8f93\u5165\u6d41\u4e2d\u8bfb\u53d6 Java \u539f\u751f\u6570\u636e\u7c7b\u578b\uff08\u5982\u00a0<code>int<\/code>\u3001<code>float<\/code>\u3001<code>boolean<\/code>\uff09\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>DataOutputStream<\/code><\/td>\n<td>\u8f93\u51fa\u6d41<\/td>\n<td>\u5141\u8bb8\u5411\u8f93\u51fa\u6d41\u4e2d\u5199\u5165 Java \u539f\u751f\u6570\u636e\u7c7b\u578b\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>ObjectInputStream<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u4ece\u8f93\u5165\u6d41\u4e2d\u8bfb\u53d6\u5e8f\u5217\u5316\u5bf9\u8c61\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>ObjectOutputStream<\/code><\/td>\n<td>\u8f93\u51fa\u6d41<\/td>\n<td>\u5c06\u5bf9\u8c61\u5e8f\u5217\u5316\u5e76\u5199\u5165\u8f93\u51fa\u6d41\u4e2d\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>PipedInputStream<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u7528\u4e8e\u5728\u7ba1\u9053\u4e2d\u8bfb\u53d6\u5b57\u8282\u6570\u636e\uff0c\u901a\u5e38\u4e0e\u00a0<code>PipedOutputStream<\/code>\u00a0\u914d\u5408\u4f7f\u7528\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>PipedOutputStream<\/code><\/td>\n<td>\u8f93\u51fa\u6d41<\/td>\n<td>\u7528\u4e8e\u5728\u7ba1\u9053\u4e2d\u5199\u5165\u5b57\u8282\u6570\u636e\uff0c\u901a\u5e38\u4e0e\u00a0<code>PipedInputStream<\/code>\u00a0\u914d\u5408\u4f7f\u7528\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>FilterInputStream<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u5b57\u8282\u8f93\u5165\u6d41\u7684\u5305\u88c5\u7c7b\uff0c\u7528\u4e8e\u5bf9\u5176\u4ed6\u8f93\u5165\u6d41\u8fdb\u884c\u8fc7\u6ee4\u5904\u7406\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>FilterOutputStream<\/code><\/td>\n<td>\u8f93\u51fa\u6d41<\/td>\n<td>\u5b57\u8282\u8f93\u51fa\u6d41\u7684\u5305\u88c5\u7c7b\uff0c\u7528\u4e8e\u5bf9\u5176\u4ed6\u8f93\u51fa\u6d41\u8fdb\u884c\u8fc7\u6ee4\u5904\u7406\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>SequenceInputStream<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u5c06\u591a\u4e2a\u8f93\u5165\u6d41\u4e32\u8054\u4e3a\u4e00\u4e2a\u8f93\u5165\u6d41\u8fdb\u884c\u5904\u7406\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th>\u7c7b\u540d<\/th>\n<th>\u7c7b\u578b<\/th>\n<th>\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><code>Reader<\/code><\/td>\n<td>\u62bd\u8c61\u7c7b (\u8f93\u5165\u6d41)<\/td>\n<td>\u6240\u6709\u5b57\u7b26\u8f93\u5165\u6d41\u7684\u8d85\u7c7b\uff0c\u5904\u7406\u5b57\u7b26\u7684\u8f93\u5165\u64cd\u4f5c\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>Writer<\/code><\/td>\n<td>\u62bd\u8c61\u7c7b (\u8f93\u51fa\u6d41)<\/td>\n<td>\u6240\u6709\u5b57\u7b26\u8f93\u51fa\u6d41\u7684\u8d85\u7c7b\uff0c\u5904\u7406\u5b57\u7b26\u7684\u8f93\u51fa\u64cd\u4f5c\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>FileReader<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u4ece\u6587\u4ef6\u4e2d\u8bfb\u53d6\u5b57\u7b26\u6570\u636e\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>FileWriter<\/code><\/td>\n<td>\u8f93\u51fa\u6d41<\/td>\n<td>\u5c06\u5b57\u7b26\u6570\u636e\u5199\u5165\u6587\u4ef6\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>BufferedReader<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u4e3a\u5b57\u7b26\u8f93\u5165\u6d41\u63d0\u4f9b\u7f13\u51b2\u529f\u80fd\uff0c\u652f\u6301\u6309\u884c\u8bfb\u53d6\uff0c\u63d0\u9ad8\u8bfb\u53d6\u6548\u7387\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>BufferedWriter<\/code><\/td>\n<td>\u8f93\u51fa\u6d41<\/td>\n<td>\u4e3a\u5b57\u7b26\u8f93\u51fa\u6d41\u63d0\u4f9b\u7f13\u51b2\u529f\u80fd\uff0c\u652f\u6301\u6309\u884c\u5199\u5165\uff0c\u63d0\u9ad8\u5199\u5165\u6548\u7387\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>CharArrayReader<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u5c06\u5b57\u7b26\u6570\u7ec4\u4f5c\u4e3a\u8f93\u5165\u6e90\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>CharArrayWriter<\/code><\/td>\n<td>\u8f93\u51fa\u6d41<\/td>\n<td>\u5c06\u6570\u636e\u5199\u5165\u5230\u5b57\u7b26\u6570\u7ec4\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>StringReader<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u5c06\u5b57\u7b26\u4e32\u4f5c\u4e3a\u8f93\u5165\u6e90\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>StringWriter<\/code><\/td>\n<td>\u8f93\u51fa\u6d41<\/td>\n<td>\u5c06\u6570\u636e\u5199\u5165\u5230\u5b57\u7b26\u4e32\u7f13\u51b2\u533a\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>PrintWriter<\/code><\/td>\n<td>\u8f93\u51fa\u6d41<\/td>\n<td>\u4fbf\u6377\u7684\u5b57\u7b26\u8f93\u51fa\u6d41\uff0c\u652f\u6301\u81ea\u52a8\u5237\u65b0\u548c\u683c\u5f0f\u5316\u8f93\u51fa\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>PipedReader<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u7528\u4e8e\u5728\u7ba1\u9053\u4e2d\u8bfb\u53d6\u5b57\u7b26\u6570\u636e\uff0c\u901a\u5e38\u4e0e\u00a0<code>PipedWriter<\/code>\u00a0\u914d\u5408\u4f7f\u7528\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>PipedWriter<\/code><\/td>\n<td>\u8f93\u51fa\u6d41<\/td>\n<td>\u7528\u4e8e\u5728\u7ba1\u9053\u4e2d\u5199\u5165\u5b57\u7b26\u6570\u636e\uff0c\u901a\u5e38\u4e0e\u00a0<code>PipedReader<\/code>\u00a0\u914d\u5408\u4f7f\u7528\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>LineNumberReader<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u5e26\u884c\u53f7\u7684\u7f13\u51b2\u5b57\u7b26\u8f93\u5165\u6d41\uff0c\u5141\u8bb8\u8ddf\u8e2a\u8bfb\u53d6\u7684\u884c\u53f7\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>PushbackReader<\/code><\/td>\n<td>\u8f93\u5165\u6d41<\/td>\n<td>\u5141\u8bb8\u5728\u8bfb\u53d6\u5b57\u7b26\u540e\u5c06\u5b57\u7b26\u63a8\u56de\u6d41\u4e2d\uff0c\u4ee5\u4fbf\u518d\u6b21\u8bfb\u53d6\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u00a0\u8f85\u52a9\u7c7b\uff08\u5176\u4ed6\u91cd\u8981\u7c7b\uff09\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th>\u7c7b\u540d<\/th>\n<th>\u7c7b\u578b<\/th>\n<th>\u63cf\u8ff0<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><code>File<\/code><\/td>\n<td>\u6587\u4ef6\u548c\u76ee\u5f55\u64cd\u4f5c<\/td>\n<td>\u7528\u4e8e\u8868\u793a\u6587\u4ef6\u6216\u76ee\u5f55\uff0c\u5e76\u63d0\u4f9b\u6587\u4ef6\u64cd\u4f5c\uff0c\u5982\u521b\u5efa\u3001\u5220\u9664\u3001\u91cd\u547d\u540d\u7b49\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>RandomAccessFile<\/code><\/td>\n<td>\u968f\u673a\u8bbf\u95ee\u6587\u4ef6<\/td>\n<td>\u652f\u6301\u6587\u4ef6\u7684\u968f\u673a\u8bbf\u95ee\uff0c\u53ef\u4ee5\u4ece\u6587\u4ef6\u7684\u4efb\u610f\u4f4d\u7f6e\u8bfb\u5199\u6570\u636e\u3002<\/td>\n<\/tr>\n<tr>\n<td><code>Console<\/code><\/td>\n<td>\u63a7\u5236\u53f0\u8f93\u5165\u8f93\u51fa<\/td>\n<td>\u63d0\u4f9b\u5bf9\u7cfb\u7edf\u63a7\u5236\u53f0\u7684\u8f93\u5165\u548c\u8f93\u51fa\u652f\u6301\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h4>FileInputStream\uff1a<\/h4>\n<p>\u8be5\u7c7b\u4ece\u6587\u4ef6\u8bfb\u53d6\u6570\u636e\uff0c\u662f\u5177\u4f53\u7c7b\u53ef\u7528new\u521b\u5efa<\/p>\n<p>\u4f8b\uff1a<\/p>\n<pre><code>InputStream f = new FileInputStream(\"C:\/java\/hello\");\n\nFile f = new File(\"C:\/java\/hello\");\nInputStream in = new FileInputStream(f);<\/code><\/pre>\n<p>\u65b9\u6cd5\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th>\u65b9\u6cd5<\/th>\n<th>\u63cf\u8ff0<\/th>\n<th>\u793a\u4f8b\u4ee3\u7801<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><code>int read()<\/code><\/td>\n<td>\u8bfb\u53d6\u4e00\u4e2a\u5b57\u8282\u7684\u6570\u636e\uff0c\u8fd4\u56de\u503c\u4e3a 0 \u5230 255 \u4e4b\u95f4\u7684\u6574\u6570\u3002\u5982\u679c\u5230\u8fbe\u6d41\u7684\u672b\u5c3e\uff0c\u8fd4\u56de -1\u3002<\/td>\n<td><code>int data = inputStream.read();<\/code><\/td>\n<\/tr>\n<tr>\n<td><code>int read(byte[] b)<\/code><\/td>\n<td>\u4ece\u8f93\u5165\u6d41\u4e2d\u8bfb\u53d6\u5b57\u8282\uff0c\u5e76\u5c06\u5176\u5b58\u50a8\u5728\u5b57\u8282\u6570\u7ec4\u00a0<code>b<\/code>\u00a0\u4e2d\uff0c\u8fd4\u56de\u5b9e\u9645\u8bfb\u53d6\u7684\u5b57\u8282\u6570\u3002\u5982\u679c\u5230\u8fbe\u6d41\u7684\u672b\u5c3e\uff0c\u8fd4\u56de -1\u3002<\/td>\n<td><code>byte[] buffer = new byte[1024]; int bytesRead = inputStream.read(buffer);<\/code><\/td>\n<\/tr>\n<tr>\n<td><code>int read(byte[] b, int off, int len)<\/code><\/td>\n<td>\u4ece\u8f93\u5165\u6d41\u4e2d\u8bfb\u53d6\u6700\u591a\u00a0<code>len<\/code>\u00a0\u4e2a\u5b57\u8282\uff0c\u5e76\u5c06\u5b83\u4eec\u5b58\u50a8\u5728\u5b57\u8282\u6570\u7ec4\u00a0<code>b<\/code>\u00a0\u7684\u00a0<code>off<\/code>\u00a0\u504f\u79fb\u4f4d\u7f6e\uff0c\u8fd4\u56de\u5b9e\u9645\u8bfb\u53d6\u7684\u5b57\u8282\u6570\u3002\u5982\u679c\u5230\u8fbe\u6d41\u7684\u672b\u5c3e\uff0c\u8fd4\u56de -1\u3002<\/td>\n<td><code>byte[] buffer = new byte[1024]; int bytesRead = inputStream.read(buffer, 0, buffer.length);<\/code><\/td>\n<\/tr>\n<tr>\n<td><code>long skip(long n)<\/code><\/td>\n<td>\u8df3\u8fc7\u5e76\u4e22\u5f03\u8f93\u5165\u6d41\u4e2d\u7684\u00a0<code>n<\/code>\u00a0\u4e2a\u5b57\u8282\uff0c\u8fd4\u56de\u5b9e\u9645\u8df3\u8fc7\u7684\u5b57\u8282\u6570\u3002<\/td>\n<td><code>long skippedBytes = inputStream.skip(100);<\/code><\/td>\n<\/tr>\n<tr>\n<td><code>int available()<\/code><\/td>\n<td>\u8fd4\u56de\u53ef\u4ee5\u8bfb\u53d6\u7684\u5b57\u8282\u6570\uff08\u4e0d\u963b\u585e\uff09\u3002<\/td>\n<td><code>int availableBytes = inputStream.available();<\/code><\/td>\n<\/tr>\n<tr>\n<td><code>void close()<\/code><\/td>\n<td>\u5173\u95ed\u8f93\u5165\u6d41\u5e76\u91ca\u653e\u4e0e\u8be5\u6d41\u76f8\u5173\u7684\u6240\u6709\u8d44\u6e90\u3002<\/td>\n<td><code>inputStream.close();<\/code><\/td>\n<\/tr>\n<tr>\n<td><code>void mark(int readlimit)<\/code><\/td>\n<td>\u5728\u6d41\u4e2d\u7684\u5f53\u524d\u4f4d\u7f6e\u8bbe\u7f6e\u6807\u8bb0\uff0c<code>readlimit<\/code>\u00a0\u662f\u53ef\u4ee5\u8bfb\u53d6\u7684\u5b57\u8282\u6570\u4e0a\u9650\u3002<\/td>\n<td><code>inputStream.mark(1024);<\/code><\/td>\n<\/tr>\n<tr>\n<td><code>void reset()<\/code><\/td>\n<td>\u5c06\u6d41\u91cd\u65b0\u5b9a\u4f4d\u5230\u4e0a\u6b21\u6807\u8bb0\u7684\u4f4d\u7f6e\uff0c\u5982\u679c\u6ca1\u6709\u6807\u8bb0\u6216\u6807\u8bb0\u5931\u6548\uff0c\u629b\u51fa\u00a0<code>IOException<\/code>\u3002<\/td>\n<td><code>inputStream.reset();<\/code><\/td>\n<\/tr>\n<tr>\n<td><code>boolean markSupported()<\/code><\/td>\n<td>\u68c0\u67e5\u5f53\u524d\u8f93\u5165\u6d41\u662f\u5426\u652f\u6301\u00a0<code>mark()<\/code>\u00a0\u548c\u00a0<code>reset()<\/code>\u00a0\u64cd\u4f5c\u3002<\/td>\n<td><code>boolean isMarkSupported = inputStream.markSupported();<\/code><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h4>FileOutputStream\uff1a<\/h4>\n<p>\u8ddf\u524d\u9762\u7684\u5dee\u4e0d\u591a\uff0c\u4e00\u6837\u7684\u521b\u5efa\u65b9\u6cd5<\/p>\n<table>\n<thead>\n<tr>\n<th>\u65b9\u6cd5<\/th>\n<th>\u63cf\u8ff0<\/th>\n<th>\u793a\u4f8b\u4ee3\u7801<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><code>void write(int b)<\/code><\/td>\n<td>\u5c06\u6307\u5b9a\u7684\u5b57\u8282\u5199\u5165\u8f93\u51fa\u6d41\uff0c<code>b<\/code>\u00a0\u7684\u4f4e 8 \u4f4d\u5c06\u88ab\u5199\u5165\u6d41\u4e2d\u3002<\/td>\n<td><code>outputStream.write(255);<\/code><\/td>\n<\/tr>\n<tr>\n<td><code>void write(byte[] b)<\/code><\/td>\n<td>\u5c06\u5b57\u8282\u6570\u7ec4\u00a0<code>b<\/code>\u00a0\u4e2d\u7684\u6240\u6709\u5b57\u8282\u5199\u5165\u8f93\u51fa\u6d41\u3002<\/td>\n<td><code>byte[] data = \"Hello\".getBytes(); outputStream.write(data);<\/code><\/td>\n<\/tr>\n<tr>\n<td><code>void write(byte[] b, int off, int len)<\/code><\/td>\n<td>\u5c06\u5b57\u8282\u6570\u7ec4\u00a0<code>b<\/code>\u00a0\u4e2d\u4ece\u504f\u79fb\u91cf\u00a0<code>off<\/code>\u00a0\u5f00\u59cb\u7684\u00a0<code>len<\/code>\u00a0\u4e2a\u5b57\u8282\u5199\u5165\u8f93\u51fa\u6d41\u3002<\/td>\n<td><code>byte[] data = \"Hello\".getBytes(); outputStream.write(data, 0, data.length);<\/code><\/td>\n<\/tr>\n<tr>\n<td><code>void flush()<\/code><\/td>\n<td>\u5237\u65b0\u8f93\u51fa\u6d41\u5e76\u5f3a\u5236\u5199\u51fa\u6240\u6709\u7f13\u51b2\u7684\u6570\u636e\uff0c\u786e\u4fdd\u6570\u636e\u88ab\u7acb\u5373\u5199\u5165\u76ee\u6807\u8f93\u51fa\u3002<\/td>\n<td><code>outputStream.flush();<\/code><\/td>\n<\/tr>\n<tr>\n<td><code>void close()<\/code><\/td>\n<td>\u5173\u95ed\u8f93\u51fa\u6d41\u5e76\u91ca\u653e\u4e0e\u8be5\u6d41\u76f8\u5173\u7684\u6240\u6709\u8d44\u6e90\u3002\u5173\u95ed\u540e\u4e0d\u80fd\u518d\u5199\u5165\u3002<\/td>\n<td><code>outputStream.close();<\/code><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h4>\u8f93\u5165\u8f93\u51fa\u6d41\u5b9e\u4f8b\uff1a<\/h4>\n<pre><code>import java.io.*;\n\npublic class fileStreamTest {\n    public static void main(String[] args) {\n        try {\n            byte bWrite[] = { 11, 21, 3, 40, 5 };\n            OutputStream os = new FileOutputStream(\"test.txt\");\n            for (int x = 0; x &lt; bWrite.length; x++) {\n                os.write(bWrite[x]); \/\/ writes the bytes\n            }\n            os.close();\n\n            InputStream is = new FileInputStream(\"test.txt\");\n            int size = is.available();\n\n            for (int i = 0; i &lt; size; i++) {\n                System.out.print((char) is.read() + \"  \"); \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\/\/\u6bcf\u6b21read()\u540e\u6307\u9488\u81ea\u52a8\u504f\u79fb\u4e00\u4f4d\u4e0b\u6b21\u8bfb\u53d6\u4e0b\u4e00\u4e2a\u5b57\u8282\n            }\n            is.close();\n        } catch (IOException e) {\n            System.out.print(\"Exception\");\n        }\n    }\n}<\/code><\/pre>\n<p>\u4f46\u8fd9\u6837\u662f\u4e8c\u8fdb\u5236\u5199\u5165\uff0c\u53ef\u80fd\u51fa\u73b0\u4e71\u7801\uff0c\u4e0b\u9762\u7ed9\u51fa\u89e3\u51b3\u65b9\u6848<\/p>\n<pre><code>\/\/\u6587\u4ef6\u540d :fileStreamTest2.java\nimport java.io.*;\n\npublic class fileStreamTest2 {\n    public static void main(String[] args) throws IOException {\n\n        File f = new File(\"a.txt\");\n        FileOutputStream fop = new FileOutputStream(f);\n        \/\/ \u6784\u5efaFileOutputStream\u5bf9\u8c61,\u6587\u4ef6\u4e0d\u5b58\u5728\u4f1a\u81ea\u52a8\u65b0\u5efa\n\n        OutputStreamWriter writer = new OutputStreamWriter(fop, \"UTF-8\");\n        \/\/ \u6784\u5efaOutputStreamWriter\u5bf9\u8c61,\u53c2\u6570\u53ef\u4ee5\u6307\u5b9a\u7f16\u7801,\u9ed8\u8ba4\u4e3a\u64cd\u4f5c\u7cfb\u7edf\u9ed8\u8ba4\u7f16\u7801,windows\u4e0a\u662fgbk\n\n        writer.append(\"\u4e2d\u6587\u8f93\u5165\");\n        \/\/ \u5199\u5165\u5230\u7f13\u51b2\u533a\n\n        writer.append(\"rn\");\n        \/\/ \u6362\u884c\n\n        writer.append(\"English\");\n        \/\/ \u5237\u65b0\u7f13\u5b58\u51b2,\u5199\u5165\u5230\u6587\u4ef6,\u5982\u679c\u4e0b\u9762\u5df2\u7ecf\u6ca1\u6709\u5199\u5165\u7684\u5185\u5bb9\u4e86,\u76f4\u63a5close\u4e5f\u4f1a\u5199\u5165\n\n        writer.close();\n        \/\/ \u5173\u95ed\u5199\u5165\u6d41,\u540c\u65f6\u4f1a\u628a\u7f13\u51b2\u533a\u5185\u5bb9\u5199\u5165\u6587\u4ef6,\u6240\u4ee5\u4e0a\u9762\u7684\u6ce8\u91ca\u6389\n\n        fop.close();\n        \/\/ \u5173\u95ed\u8f93\u51fa\u6d41,\u91ca\u653e\u7cfb\u7edf\u8d44\u6e90\n\n        FileInputStream fip = new FileInputStream(f);\n        \/\/ \u6784\u5efaFileInputStream\u5bf9\u8c61\n\n        InputStreamReader reader = new InputStreamReader(fip, \"UTF-8\");\n        \/\/ \u6784\u5efaInputStreamReader\u5bf9\u8c61,\u7f16\u7801\u4e0e\u5199\u5165\u76f8\u540c\n\n        StringBuffer sb = new StringBuffer();\n        while (reader.ready()) {\n            sb.append((char) reader.read());\n            \/\/ \u8f6c\u6210char\u52a0\u5230StringBuffer\u5bf9\u8c61\u4e2d\n        }\n        System.out.println(sb.toString());\n        reader.close();\n        \/\/ \u5173\u95ed\u8bfb\u53d6\u6d41\n\n        fip.close();\n        \/\/ \u5173\u95ed\u8f93\u5165\u6d41,\u91ca\u653e\u7cfb\u7edf\u8d44\u6e90\n\n    }\n}<\/code><\/pre>\n<h4>\u6587\u4ef6\u76ee\u5f55\u64cd\u4f5c\uff1a<\/h4>\n<ul>\n<li>mkdir( )\u65b9\u6cd5\u521b\u5efa\u4e00\u4e2a\u6587\u4ef6\u5939\uff0c\u6210\u529f\u5219\u8fd4\u56detrue\uff0c\u5931\u8d25\u5219\u8fd4\u56defalse\u3002\u5931\u8d25\u8868\u660eFile\u5bf9\u8c61\u6307\u5b9a\u7684\u8def\u5f84\u5df2\u7ecf\u5b58\u5728\uff0c\u6216\u8005\u7531\u4e8e\u6574\u4e2a\u8def\u5f84\u8fd8\u4e0d\u5b58\u5728\uff0c\u8be5\u6587\u4ef6\u5939\u4e0d\u80fd\u88ab\u521b\u5efa\u3002<\/li>\n<li>mkdirs()\u65b9\u6cd5\u521b\u5efa\u4e00\u4e2a\u6587\u4ef6\u5939\u548c\u5b83\u7684\u6240\u6709\u7236\u6587\u4ef6\u5939\u3002<\/li>\n<li>delete()\u65b9\u6cd5\u5220\u9664\u6587\u4ef6<\/li>\n<\/ul>\n<p><strong>\u4f8b\u5b50\uff1a<\/strong><\/p>\n<p>\u521b\u5efa\u76ee\u5f55\uff1a<\/p>\n<pre><code>import java.io.File;\n\npublic class CreateDir {\n    public static void main(String[] args) {\n        String dirname = \"\/tmp\/user\/java\/bin\";\n        File d = new File(dirname);\n        \/\/\u4ec5\u4ec5\u521b\u5efa\u5bf9\u8c61\u4f5c\u4e3a\u8def\u5f84\u5f15\u5bfc\uff0c\u4e0b\u9762\u521b\u5efa\u76ee\u5f55\n        d.mkdirs();\n    }\n}<\/code><\/pre>\n<p>\u8bfb\u53d6\u76ee\u5f55\uff1a<\/p>\n<pre><code>import java.io.File;\n\npublic class DirList {\n    public static void main(String args[]) {\n        String dirname = \"\/tmp\";\n        File f1 = new File(dirname);\n        if (f1.isDirectory()) {\n            System.out.println(\"\u76ee\u5f55 \" + dirname);\n            String s[] = f1.list();\n            for (int i = 0; i &lt; s.length; i++) {\n                File f = new File(dirname + \"\/\" + s[i]);\n                if (f.isDirectory()) {\n                    System.out.println(s[i] + \" \u662f\u4e00\u4e2a\u76ee\u5f55\");\n                } else {\n                    System.out.println(s[i] + \" \u662f\u4e00\u4e2a\u6587\u4ef6\");\n                }\n            }\n        } else {\n            System.out.println(dirname + \" \u4e0d\u662f\u4e00\u4e2a\u76ee\u5f55\");\n        }\n    }\n}<\/code><\/pre>\n<p>\u5220\u9664\u76ee\u5f55\/\u6587\u4ef6\uff08\u4f7f\u7528\u9012\u5f52\uff09\uff1a<\/p>\n<pre><code>import java.io.File;\n\npublic class DeleteFileDemo {\n    public static void main(String[] args) {\n        \/\/ \u8fd9\u91cc\u4fee\u6539\u4e3a\u81ea\u5df1\u7684\u6d4b\u8bd5\u76ee\u5f55\n        File folder = new File(\"\/tmp\/java\/\");\n        deleteFolder(folder);\n    }\n\n    \/\/ \u5220\u9664\u6587\u4ef6\u53ca\u76ee\u5f55\n    public static void deleteFolder(File folder) {\n        File[] files = folder.listFiles();\n        if (files != null) {\n            for (File f : files) {\n                if (f.isDirectory()) {\n                    deleteFolder(f);\n                } else {\n                    f.delete();\n                }\n            }\n        }\n        folder.delete();\n    }\n}<\/code><\/pre>\n<h2>Scanner \u7c7b\uff1a<\/h2>\n<p>java\u53ef\u7528\u901a\u8fc7Scanner\u7c7b\u8bfb\u53d6\u8f93\u5165<\/p>\n<p>\u521b\u5efaScanner\u5bf9\u8c61\uff1a<\/p>\n<pre><code>Scanner s = new Scanner(System.in);<\/code><\/pre>\n<h3>\u65b9\u6cd5\uff1a<\/h3>\n<p>\u4e3b\u8981\u662fnext()\u548cnextLine(),\u533a\u522b\u5982\u4e0b\uff1a<\/p>\n<p>next():<\/p>\n<ul>\n<li>1\u3001\u4e00\u5b9a\u8981\u8bfb\u53d6\u5230\u6709\u6548\u5b57\u7b26\u540e\u624d\u53ef\u4ee5\u7ed3\u675f\u8f93\u5165\u3002<\/li>\n<li>2\u3001\u5bf9\u8f93\u5165\u6709\u6548\u5b57\u7b26\u4e4b\u524d\u9047\u5230\u7684\u7a7a\u767d\uff0cnext() \u65b9\u6cd5\u4f1a\u81ea\u52a8\u5c06\u5176\u53bb\u6389\u3002<\/li>\n<li>3\u3001\u53ea\u6709\u8f93\u5165\u6709\u6548\u5b57\u7b26\u540e\u624d\u5c06\u5176\u540e\u9762\u8f93\u5165\u7684\u7a7a\u767d\u4f5c\u4e3a\u5206\u9694\u7b26\u6216\u8005\u7ed3\u675f\u7b26\u3002<\/li>\n<li>next() \u4e0d\u80fd\u5f97\u5230\u5e26\u6709\u7a7a\u683c\u7684\u5b57\u7b26\u4e32\u3002<\/li>\n<\/ul>\n<p>nextLine()\uff1a<\/p>\n<ul>\n<li>1\u3001\u4ee5Enter\u4e3a\u7ed3\u675f\u7b26,\u4e5f\u5c31\u662f\u8bf4 nextLine()\u65b9\u6cd5\u8fd4\u56de\u7684\u662f\u8f93\u5165\u56de\u8f66\u4e4b\u524d\u7684\u6240\u6709\u5b57\u7b26\u3002<\/li>\n<li>2\u3001\u53ef\u4ee5\u83b7\u5f97\u7a7a\u767d\u3002<\/li>\n<\/ul>\n<h4>\u5176\u4ed6\u65b9\u6cd5\uff1a<\/h4>\n<p>\u6784\u9020\u65b9\u6cd5\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th><code>Scanner(File source)<\/code><\/th>\n<th>\u4ece\u6587\u4ef6\u521b\u5efa Scanner<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><code>Scanner(InputStream source)<\/code><\/td>\n<td>\u4ece\u8f93\u5165\u6d41\u521b\u5efa Scanner<\/td>\n<\/tr>\n<tr>\n<td><code>Scanner(String source)<\/code><\/td>\n<td>\u4ece\u5b57\u7b26\u4e32\u521b\u5efa Scanner<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u57fa\u672c\u8f93\u5165\u65b9\u6cd5\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th><code>boolean hasNext()<\/code><\/th>\n<th>\u68c0\u67e5\u662f\u5426\u6709\u4e0b\u4e00\u4e2a\u6807\u8bb0\uff08\u4ee5\u7a7a\u683c\u5206\u9694\uff09<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><code>String next()<\/code><\/td>\n<td>\u8bfb\u53d6\u4e0b\u4e00\u4e2a\u6807\u8bb0\uff08\u5b57\u7b26\u4e32\uff09<\/td>\n<\/tr>\n<tr>\n<td><code>boolean hasNextLine()<\/code><\/td>\n<td>\u68c0\u67e5\u662f\u5426\u6709\u4e0b\u4e00\u884c<\/td>\n<\/tr>\n<tr>\n<td><code>String nextLine()<\/code><\/td>\n<td>\u8bfb\u53d6\u4e0b\u4e00\u884c\u5185\u5bb9<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u7c7b\u578b\u68c0\u67e5\u65b9\u6cd5\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th><code>boolean hasNextInt()<\/code><\/th>\n<th>\u68c0\u67e5\u4e0b\u4e00\u4e2a\u6807\u8bb0\u662f\u5426\u4e3a\u6574\u6570<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><code>boolean hasNextDouble()<\/code><\/td>\n<td>\u68c0\u67e5\u4e0b\u4e00\u4e2a\u6807\u8bb0\u662f\u5426\u4e3a\u53cc\u7cbe\u5ea6\u6d6e\u70b9\u6570<\/td>\n<\/tr>\n<tr>\n<td><code>boolean hasNextBoolean()<\/code><\/td>\n<td>\u68c0\u67e5\u4e0b\u4e00\u4e2a\u6807\u8bb0\u662f\u5426\u4e3a\u5e03\u5c14\u503c<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u7c7b\u578b\u8bfb\u53d6\u65b9\u6cd5\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th><code>int nextInt()<\/code><\/th>\n<th>\u8bfb\u53d6\u4e0b\u4e00\u4e2a\u6574\u6570<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><code>double nextDouble()<\/code><\/td>\n<td>\u8bfb\u53d6\u4e0b\u4e00\u4e2a\u53cc\u7cbe\u5ea6\u6d6e\u70b9\u6570<\/td>\n<\/tr>\n<tr>\n<td><code>boolean nextBoolean()<\/code><\/td>\n<td>\u8bfb\u53d6\u4e0b\u4e00\u4e2a\u5e03\u5c14\u503c<\/td>\n<\/tr>\n<tr>\n<td><code>long nextLong()<\/code><\/td>\n<td>\u8bfb\u53d6\u4e0b\u4e00\u4e2a\u957f\u6574\u6570<\/td>\n<\/tr>\n<tr>\n<td><code>float nextFloat()<\/code><\/td>\n<td>\u8bfb\u53d6\u4e0b\u4e00\u4e2a\u5355\u7cbe\u5ea6\u6d6e\u70b9\u6570<\/td>\n<\/tr>\n<tr>\n<td><code>short nextShort()<\/code><\/td>\n<td>\u8bfb\u53d6\u4e0b\u4e00\u4e2a\u77ed\u6574\u6570<\/td>\n<\/tr>\n<tr>\n<td><code>byte nextByte()<\/code><\/td>\n<td>\u8bfb\u53d6\u4e0b\u4e00\u4e2a\u5b57\u8282<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u5206\u9694\u7b26\u63a7\u5236\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th><code>Scanner useDelimiter(String pattern)<\/code><\/th>\n<th>\u8bbe\u7f6e\u5206\u9694\u7b26\u6a21\u5f0f<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><code>Scanner useDelimiter(Pattern pattern)<\/code><\/td>\n<td>\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\u8bbe\u7f6e\u5206\u9694\u7b26<\/td>\n<\/tr>\n<tr>\n<td><code>String delimiter()<\/code><\/td>\n<td>\u8fd4\u56de\u5f53\u524d\u4f7f\u7528\u7684\u5206\u9694\u7b26\u6a21\u5f0f<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u5176\u4ed6\u65b9\u6cd5\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th><code>void close()<\/code><\/th>\n<th>\u5173\u95ed\u626b\u63cf\u5668<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><code>Scanner skip(Pattern pattern)<\/code><\/td>\n<td>\u8df3\u8fc7\u5339\u914d\u6307\u5b9a\u6a21\u5f0f\u7684\u8f93\u5165<\/td>\n<\/tr>\n<tr>\n<td><code>Scanner skip(String pattern)<\/code><\/td>\n<td>\u8df3\u8fc7\u5339\u914d\u6307\u5b9a\u5b57\u7b26\u4e32\u7684\u8f93\u5165<\/td>\n<\/tr>\n<tr>\n<td><code>String findInLine(Pattern pattern)<\/code><\/td>\n<td>\u5728\u5f53\u524d\u884c\u4e2d\u67e5\u627e\u6307\u5b9a\u6a21\u5f0f<\/td>\n<\/tr>\n<tr>\n<td><code>String findInLine(String pattern)<\/code><\/td>\n<td>\u5728\u5f53\u524d\u884c\u4e2d\u67e5\u627e\u6307\u5b9a\u5b57\u7b26\u4e32<\/td>\n<\/tr>\n<tr>\n<td><code>Scanner reset()<\/code><\/td>\n<td>\u91cd\u7f6e\u626b\u63cf\u5668<\/td>\n<\/tr>\n<tr>\n<td><code>Locale locale()<\/code><\/td>\n<td>\u8fd4\u56de\u626b\u63cf\u5668\u5f53\u524d\u4f7f\u7528\u7684\u533a\u57df\u8bbe\u7f6e<\/td>\n<\/tr>\n<tr>\n<td><code>Scanner useLocale(Locale locale)<\/code><\/td>\n<td>\u8bbe\u7f6e\u626b\u63cf\u5668\u7684\u533a\u57df\u8bbe\u7f6e<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<pre><code>import java.util.Scanner;\n\npublic class ScannerDemo {\n    public static void main(String[] args) {\n        Scanner scan = new Scanner(System.in);\n        \/\/ \u4ece\u952e\u76d8\u63a5\u6536\u6570\u636e\n        int i = 0;\n        float f = 0.0f;\n        System.out.print(\"\u8f93\u5165\u6574\u6570\uff1a\");\n        if (scan.hasNextInt()) {\n            \/\/ \u5224\u65ad\u8f93\u5165\u7684\u662f\u5426\u662f\u6574\u6570\n            i = scan.nextInt();\n            \/\/ \u63a5\u6536\u6574\u6570\n            System.out.println(\"\u6574\u6570\u6570\u636e\uff1a\" + i);\n        } else {\n            \/\/ \u8f93\u5165\u9519\u8bef\u7684\u4fe1\u606f\n            System.out.println(\"\u8f93\u5165\u7684\u4e0d\u662f\u6574\u6570\uff01\");\n        }\n        System.out.print(\"\u8f93\u5165\u5c0f\u6570\uff1a\");\n        if (scan.hasNextFloat()) {\n            \/\/ \u5224\u65ad\u8f93\u5165\u7684\u662f\u5426\u662f\u5c0f\u6570\n            f = scan.nextFloat();\n            \/\/ \u63a5\u6536\u5c0f\u6570\n            System.out.println(\"\u5c0f\u6570\u6570\u636e\uff1a\" + f);\n        } else {\n            \/\/ \u8f93\u5165\u9519\u8bef\u7684\u4fe1\u606f\n            System.out.println(\"\u8f93\u5165\u7684\u4e0d\u662f\u5c0f\u6570\uff01\");\n        }\n        scan.close();\n    }\n} \n\nclass RunoobTest {\n    public static void main(String[] args) {\n        System.out.println(\"\u8bf7\u8f93\u5165\u6570\u5b57\uff1a\");\n        Scanner scan = new Scanner(System.in);\n\n        double sum = 0;\n        int m = 0;\n\n        while (scan.hasNextDouble()) {\n            double x = scan.nextDouble();\n            m = m + 1;\n            sum = sum + x;\n        }\n\n        System.out.println(m + \"\u4e2a\u6570\u7684\u548c\u4e3a\" + sum);\n        System.out.println(m + \"\u4e2a\u6570\u7684\u5e73\u5747\u503c\u662f\" + (sum \/ m));\n        scan.close();\n    }\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>java\u57fa\u7840 \u4e00\u4e9b\u57fa\u672c\u7684\uff1a \u00a0\u00a0\u00a0\u00a0\u00a0\u00a01\uff1ajava\u4e2d\u6587\u4ef6\u540d\u8981\u4e0e\u7c7b\u540d\u4e00\u81f4 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a02\uff1a\u7f16\u8bd1\u6587\u4ef6\uff1aJava\u6587 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-35","post","type-post","status-publish","format-standard","hentry","category-3"],"_links":{"self":[{"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/posts\/35","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/comments?post=35"}],"version-history":[{"count":1,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/posts\/35\/revisions"}],"predecessor-version":[{"id":36,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/posts\/35\/revisions\/36"}],"wp:attachment":[{"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/media?parent=35"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/categories?post=35"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/tags?post=35"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}