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19 package org.netbeans.modules.j2ee.metadata;
20
21 import org.netbeans.spi.java.classpath.ClassPathImplementation;
22
23 import java.util.List  ;
24 import java.util.ArrayList ;
25 import java.util.Iterator ;
26 import java.util.Collections ;
27 import java.beans.PropertyChangeListener ;
28 import java.beans.PropertyChangeEvent ;
29 import java.lang.ref.WeakReference ;
30 import java.util.concurrent.CopyOnWriteArraySet ;
31 import org.netbeans.spi.java.classpath.PathResourceImplementation;
32 import org.openide.util.Utilities;
33 import org.openide.util.WeakListeners;
34
35
40 public class WeakProxyClassPathImplementation implements ClassPathImplementation {
41
42 final private CopyOnWriteArraySet <WeakReference <ClassPathImplementation>> classPathRefs = new CopyOnWriteArraySet <WeakReference <ClassPathImplementation>>();
43 final private PropertyChangeListener classPathsListener = new DelegatesListener ();
44
45 private List <PathResourceImplementation> resourcesCache;
46 private ArrayList <PropertyChangeListener > listeners;
47
48 public WeakProxyClassPathImplementation (ClassPathImplementation[] classPaths) {
49 if (classPaths == null) {
50 throw new IllegalArgumentException ();
51 }
52 for (ClassPathImplementation classPath : classPaths) {
53 if (classPaths == null) {
54 continue;
55 }
56 classPath.addPropertyChangeListener (WeakListeners.propertyChange(classPathsListener, classPath));
57 classPathRefs.add(new CleanupReference<ClassPathImplementation>(classPath));
58 }
59 }
60
61 public List <PathResourceImplementation> getResources() {
62 synchronized (this) {
63 if (this.resourcesCache != null) {
64 return this.resourcesCache;
65 }
66 }
67 List <PathResourceImplementation> result = new ArrayList <PathResourceImplementation>(classPathRefs.size() * 10);
68 for (WeakReference <ClassPathImplementation> classPathRef : classPathRefs) {
69 ClassPathImplementation classPath = classPathRef.get();
70 if (classPath == null) {
71 continue;
72 }
73 List <? extends PathResourceImplementation> subPath = classPath.getResources();
74 assert subPath != null : "ClassPathImplementation.getResources() returned null. ClassPathImplementation.class: "
75 + classPath.getClass().toString() + " ClassPathImplementation: " + classPath.toString();
76 result.addAll(subPath);
77 }
78 synchronized (this) {
79 if (this.resourcesCache == null) {
80 resourcesCache = Collections.unmodifiableList(result);
81 }
82 return this.resourcesCache;
83 }
84 }
85
86 public synchronized void addPropertyChangeListener(PropertyChangeListener listener) {
87 if (this.listeners == null)
88 this.listeners = new ArrayList <PropertyChangeListener >();
89 this.listeners.add (listener);
90 }
91
92 public synchronized void removePropertyChangeListener(PropertyChangeListener listener) {
93 if (this.listeners == null)
94 return;
95 this.listeners.remove (listener);
96 }
97
98 public String toString () {
99 StringBuffer builder = new StringBuffer ("["); for (WeakReference <ClassPathImplementation> classPathRef : classPathRefs) {
101 ClassPathImplementation classPath = classPathRef.get();
102 if (classPath != null) {
103 builder.append (classPath.toString());
104 builder.append(", "); }
106 }
107 builder.append ("]"); return builder.toString ();
109 }
110
111 private void change(String propertyName) {
112 Iterator it = null;
113 synchronized (this) {
114 WeakProxyClassPathImplementation.this.resourcesCache = null; if (WeakProxyClassPathImplementation.this.listeners == null) {
116 return;
117 }
118 it = ((ArrayList )WeakProxyClassPathImplementation.this.listeners.clone()).iterator();
119 }
120 PropertyChangeEvent event = new PropertyChangeEvent (this, propertyName, null, null);
121 while (it.hasNext()) {
122 ((PropertyChangeListener )it.next()).propertyChange (event);
123 }
124 }
125
126 private class DelegatesListener implements PropertyChangeListener {
127
128 public void propertyChange(PropertyChangeEvent evt) {
129 change(evt.getPropertyName());
130 }
131 }
132
133 private class CleanupReference<T> extends WeakReference <T> implements Runnable {
134
135 public CleanupReference(T referent) {
136 super(referent, Utilities.activeReferenceQueue());
137 }
138
139 public void run() {
140 classPathRefs.remove(this);
141 change(ClassPathImplementation.PROP_RESOURCES);
142 }
143 }
144
145 }
146 |
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