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19 package org.eclipse.jetty.servlet.listener;
20
21 import java.lang.reflect.Field;
22 import java.util.Iterator;
23 import java.util.concurrent.ConcurrentHashMap;
24
25 import javax.servlet.ServletContextEvent;
26 import javax.servlet.ServletContextListener;
27
28 import org.eclipse.jetty.util.Loader;
29 import org.eclipse.jetty.util.log.Log;
30 import org.eclipse.jetty.util.log.Logger;
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41 public class ELContextCleaner implements ServletContextListener
42 {
43 private static final Logger LOG = Log.getLogger(ELContextCleaner.class);
44
45
46 public void contextInitialized(ServletContextEvent sce)
47 {
48 }
49
50 public void contextDestroyed(ServletContextEvent sce)
51 {
52 try
53 {
54
55 Class beanELResolver = Loader.loadClass(this.getClass(), "javax.el.BeanELResolver");
56
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58 Field field = getField(beanELResolver);
59
60
61 purgeEntries(field);
62
63 LOG.info("javax.el.BeanELResolver purged");
64 }
65
66 catch (ClassNotFoundException e)
67 {
68
69 }
70 catch (SecurityException e)
71 {
72 LOG.warn("Cannot purge classes from javax.el.BeanELResolver", e);
73 }
74 catch (IllegalArgumentException e)
75 {
76 LOG.warn("Cannot purge classes from javax.el.BeanELResolver", e);
77 }
78 catch (IllegalAccessException e)
79 {
80 LOG.warn("Cannot purge classes from javax.el.BeanELResolver", e);
81 }
82 catch (NoSuchFieldException e)
83 {
84 LOG.info("Not cleaning cached beans: no such field javax.el.BeanELResolver.properties");
85 }
86
87 }
88
89
90 protected Field getField (Class beanELResolver)
91 throws SecurityException, NoSuchFieldException
92 {
93 if (beanELResolver == null)
94 return null;
95
96 return beanELResolver.getDeclaredField("properties");
97 }
98
99 protected void purgeEntries (Field properties)
100 throws IllegalArgumentException, IllegalAccessException
101 {
102 if (properties == null)
103 return;
104
105 if (!properties.isAccessible())
106 properties.setAccessible(true);
107
108 ConcurrentHashMap map = (ConcurrentHashMap) properties.get(null);
109 if (map == null)
110 return;
111
112 Iterator<Class> itor = map.keySet().iterator();
113 while (itor.hasNext())
114 {
115 Class clazz = itor.next();
116 LOG.info("Clazz: "+clazz+" loaded by "+clazz.getClassLoader());
117 if (Thread.currentThread().getContextClassLoader().equals(clazz.getClassLoader()))
118 {
119 itor.remove();
120 LOG.info("removed");
121 }
122 else
123 LOG.info("not removed: "+"contextclassloader="+Thread.currentThread().getContextClassLoader()+"clazz's classloader="+clazz.getClassLoader());
124 }
125 }
126 }