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1
7 package org.jboss.jms.util;
8
9 import java.util.ArrayList  ;
10 import java.util.Collection ;
11 import java.util.Comparator ;
12 import java.util.Iterator ;
13 import java.util.SortedSet ;
14 import java.util.TreeSet ;
15
16
21 public class SortedSetPriorityQueue implements PriorityQueue
22 {
23 private SortedSet contents = null;
24
25 public SortedSetPriorityQueue()
26 {
27 this.contents = new TreeSet ();
28 }
29
30 public SortedSetPriorityQueue(Comparator comparator)
31 {
32 this.contents = new TreeSet (comparator);
33 }
34
35 public void enqueue(Object object)
36 {
37 this.contents.add(object);
38 }
39
40 public void enqueue(Collection collection)
41 {
42 this.contents.addAll(collection);
43 }
44
45 public Object dequeue()
46 {
47 if (!this.contents.isEmpty())
48 {
49 Iterator iterator = this.contents.iterator();
50 Object object = iterator.next();
51 iterator.remove();
52 return object;
53 }
54 else
55 {
56 return null;
57 }
58 }
59
60 public Collection dequeue(int maximumItems)
61 {
62 Collection items = new ArrayList (maximumItems);
63 Iterator iterator = this.contents.iterator();
64 int i = 0;
65 while (iterator.hasNext() && i++ < maximumItems)
66 {
67 items.add(iterator.next());
68 iterator.remove();
69 }
70 return items;
71 }
72
73 public Object peek()
74 {
75 return this.contents.first();
76 }
77
78 public Collection peek(int maximumItems)
79 {
80 Collection items = new ArrayList (maximumItems);
81 Iterator iterator = this.contents.iterator();
82 int i = 0;
83 while (iterator.hasNext() && i++ < maximumItems)
84 {
85 items.add(iterator.next());
86 }
87 return items;
88 }
89
90 public void purge()
91 {
92 this.contents.clear();
93 }
94
95 public int size()
96 {
97 return this.contents.size();
98 }
99
100 public boolean isEmpty()
101 {
102 return this.contents.isEmpty();
103 }
104 }
105 |
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