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1   package org.apache.jcs.engine;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *   http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  import java.util.Hashtable;
23  import java.util.Iterator;
24  import java.util.Map;
25  
26  import org.apache.jcs.engine.behavior.ICache;
27  
28  /***
29   * Used to associates a set of [cache listener to cache event queue] for a
30   * cache.
31   */
32  public class CacheListeners
33  {
34      /*** The cache using the queue. */
35      public final ICache cache;
36  
37      /*** Map ICacheListener to ICacheEventQueue */
38      public final Map eventQMap = new Hashtable();
39  
40      /***
41       * Constructs with the given cache.
42       * <p>
43       * @param cache
44       */
45      public CacheListeners( ICache cache )
46      {
47          if ( cache == null )
48          {
49              throw new IllegalArgumentException( "cache must not be null" );
50          }
51          this.cache = cache;
52      }
53      
54      /*** @return info on the listeners */
55      public String toString()
56      {
57          StringBuffer buffer = new StringBuffer();
58          buffer.append( "\n CacheListeners" );
59          if ( cache != null )
60          {
61              buffer.append( "\n Region = " + cache.getCacheName() );
62          }
63          if ( eventQMap != null )
64          {
65              buffer.append( "\n Event Queue Map " );
66              buffer.append( "\n size = " + eventQMap.size() );
67              Iterator it = eventQMap.entrySet().iterator();
68              while ( it.hasNext() )
69              {
70                  buffer.append( "\n Entry: " + it.next() );               
71              }                
72          }
73          else
74          {
75              buffer.append( "\n No Listeners. " );
76          }
77          return buffer.toString();
78      }
79  }