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1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *  
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *  
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License. 
18   *  
19   */
20  package org.apache.directory.server.xdbm;
21  
22  
23  import org.apache.directory.server.core.cursor.ClosureMonitor;
24  import org.apache.directory.server.core.cursor.CursorIterator;
25  import org.apache.directory.server.core.cursor.DefaultClosureMonitor;
26  
27  import java.util.Iterator;
28  
29  
30  /**
31   * An abstract TupleCursor.
32   *
33   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
34   * @version $Rev$
35   */
36  public abstract class AbstractIndexCursor<K, E> implements IndexCursor<K, E>
37  {
38      private ClosureMonitor monitor = new DefaultClosureMonitor();
39  
40      
41      public final void setClosureMonitor( ClosureMonitor monitor )
42      {
43          if ( monitor == null )
44          {
45              throw new NullPointerException( "monitor" );
46          }
47          
48          this.monitor = monitor;
49      }
50      
51  
52      protected final void checkNotClosed( String operation ) throws Exception
53      {
54          monitor.checkNotClosed();
55      }
56  
57  
58      public final boolean isClosed()
59      {
60          return monitor.isClosed();
61      }
62  
63  
64      public void close() throws Exception
65      {
66          monitor.close();
67      }
68  
69  
70      public void close( Exception cause ) throws Exception
71      {
72          monitor.close( cause );
73      }
74  
75  
76      public Iterator<IndexEntry<K, E>> iterator()
77      {
78          return new CursorIterator<IndexEntry<K, E>>( this );
79      }
80  }