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1
24 package org.riotfamily.common.web.util;
25
26 import java.util.ArrayList  ;
27 import java.util.Collection ;
28 import java.util.Iterator ;
29
30 import javax.servlet.http.HttpSession ;
31 import javax.servlet.http.HttpSessionBindingEvent ;
32 import javax.servlet.http.HttpSessionBindingListener ;
33
34 import org.apache.commons.logging.Log;
35 import org.apache.commons.logging.LogFactory;
36
37
47 public class SessionReferenceRemover implements HttpSessionBindingListener {
48
49 private static final Log log = LogFactory
50 .getLog(SessionReferenceRemover.class);
51
52 private static final String SESSION_KEY =
53 SessionReferenceRemover.class.getName();
54
55 private ArrayList references = new ArrayList ();
56
57
58 private SessionReferenceRemover() {
59 }
60
61 private void addReference(Collection collection, Object value) {
62 references.add(new SessionReference(collection, value));
63 }
64
65 public void valueBound(HttpSessionBindingEvent event) {
66 }
67
68 public void valueUnbound(HttpSessionBindingEvent event) {
69 log.info("Session invalidated - removing " + references.size()
70 + " references.");
71
72 Iterator it = references.iterator();
73 while (it.hasNext()) {
74 SessionReference ref = (SessionReference) it.next();
75 ref.remove();
76 }
77 references.clear();
78 }
79
80
84 public static void removeFromCollectionOnInvalidation(
85 HttpSession session, Collection collection, Object value) {
86
87 SessionReferenceRemover remover = (SessionReferenceRemover)
88 session.getAttribute(SESSION_KEY);
89
90 if (remover == null) {
91 remover = new SessionReferenceRemover();
92 session.setAttribute(SESSION_KEY, remover);
93 }
94 remover.addReference(collection, value);
95 }
96
97 private static class SessionReference {
98
99 private Collection collection;
100
101 private Object value;
102
103 public SessionReference(Collection collection, Object value) {
104 this.collection = collection;
105 this.value = value;
106 }
107
108 public void remove() {
109 collection.remove(value);
110 }
111
112 }
113
114 }
115 |
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