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1
7
8 package com.sun.jmx.mbeanserver;
9
10 import java.lang.ref.WeakReference  ;
11 import java.util.WeakHashMap ;
12 import javax.management.Descriptor ;
13 import javax.management.ImmutableDescriptor ;
14 import javax.management.JMX ;
15
16 public class DescriptorCache {
17 private DescriptorCache() {
18 }
19
20 static DescriptorCache getInstance() {
21 return instance;
22 }
23
24 public static DescriptorCache getInstance(JMX proof) {
25 if (proof != null)
26 return instance;
27 else
28 return null;
29 }
30
31 public ImmutableDescriptor get(ImmutableDescriptor descriptor) {
32 WeakReference <ImmutableDescriptor > wr = map.get(descriptor);
33 ImmutableDescriptor got = (wr == null) ? null : wr.get();
34 if (got != null)
35 return got;
36 map.put(descriptor, new WeakReference <ImmutableDescriptor >(descriptor));
37 return descriptor;
38 }
39
40 public ImmutableDescriptor union(Descriptor ... descriptors) {
41 return get(ImmutableDescriptor.union(descriptors));
42 }
43
44 private final static DescriptorCache instance = new DescriptorCache();
45 private final WeakHashMap <ImmutableDescriptor ,
46 WeakReference <ImmutableDescriptor >>
47 map = new WeakHashMap <ImmutableDescriptor ,
48 WeakReference <ImmutableDescriptor >>();
49 }
50 |
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