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14 package org.eclipse.jetty.servlet.listener;
15
16 import java.lang.reflect.Field;
17 import java.lang.reflect.InvocationTargetException;
18 import java.lang.reflect.Method;
19 import java.util.Iterator;
20 import java.util.concurrent.ConcurrentHashMap;
21
22 import javax.servlet.ServletContextEvent;
23 import javax.servlet.ServletContextListener;
24
25 import org.eclipse.jetty.util.Loader;
26 import org.eclipse.jetty.util.log.Log;
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37 public class ELContextCleaner implements ServletContextListener
38 {
39
40 public void contextInitialized(ServletContextEvent sce)
41 {
42 }
43
44 public void contextDestroyed(ServletContextEvent sce)
45 {
46 try
47 {
48
49 Class beanELResolver = Loader.loadClass(this.getClass(), "javax.el.BeanELResolver");
50
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52 Field field = getField(beanELResolver);
53
54
55 purgeEntries(field);
56
57 Log.info("javax.el.BeanELResolver purged");
58 }
59
60 catch (ClassNotFoundException e)
61 {
62
63 }
64 catch (SecurityException e)
65 {
66 Log.warn("Cannot purge classes from javax.el.BeanELResolver", e);
67 }
68 catch (IllegalArgumentException e)
69 {
70 Log.warn("Cannot purge classes from javax.el.BeanELResolver", e);
71 }
72 catch (IllegalAccessException e)
73 {
74 Log.warn("Cannot purge classes from javax.el.BeanELResolver", e);
75 }
76 catch (NoSuchFieldException e)
77 {
78 Log.warn("Cannot purge classes from javax.el.BeanELResolver", e);
79 }
80
81 }
82
83
84 protected Field getField (Class beanELResolver)
85 throws SecurityException, NoSuchFieldException
86 {
87 if (beanELResolver == null)
88 return null;
89
90 return beanELResolver.getDeclaredField("properties");
91 }
92
93 protected void purgeEntries (Field properties)
94 throws IllegalArgumentException, IllegalAccessException
95 {
96 if (properties == null)
97 return;
98
99 if (!properties.isAccessible())
100 properties.setAccessible(true);
101
102 ConcurrentHashMap map = (ConcurrentHashMap) properties.get(null);
103 if (map == null)
104 return;
105
106 Iterator<Class> itor = map.keySet().iterator();
107 while (itor.hasNext())
108 {
109 Class clazz = itor.next();
110 Log.info("Clazz: "+clazz+" loaded by "+clazz.getClassLoader());
111 if (Thread.currentThread().getContextClassLoader().equals(clazz.getClassLoader()))
112 {
113 itor.remove();
114 Log.info("removed");
115 }
116 else
117 Log.info("not removed: "+"contextclassloader="+Thread.currentThread().getContextClassLoader()+"clazz's classloader="+clazz.getClassLoader());
118 }
119 }
120 }