001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one
003     *  or more contributor license agreements.  See the NOTICE file
004     *  distributed with this work for additional information
005     *  regarding copyright ownership.  The ASF licenses this file
006     *  to you under the Apache License, Version 2.0 (the
007     *  "License"); you may not use this file except in compliance
008     *  with the License.  You may obtain a copy of the License at
009     *  
010     *    http://www.apache.org/licenses/LICENSE-2.0
011     *  
012     *  Unless required by applicable law or agreed to in writing,
013     *  software distributed under the License is distributed on an
014     *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     *  KIND, either express or implied.  See the License for the
016     *  specific language governing permissions and limitations
017     *  under the License. 
018     *  
019     */
020    package org.apache.directory.server.xdbm;
021    
022    
023    import java.util.Iterator;
024    
025    import org.apache.directory.shared.ldap.cursor.ClosureMonitor;
026    import org.apache.directory.shared.ldap.cursor.CursorIterator;
027    import org.apache.directory.shared.ldap.cursor.DefaultClosureMonitor;
028    
029    
030    /**
031     * An abstract TupleCursor.
032     *
033     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
034     * @version $Rev$
035     */
036    public abstract class AbstractIndexCursor<K, E, ID> implements IndexCursor<K, E, ID>
037    {
038        private ClosureMonitor monitor = new DefaultClosureMonitor();
039    
040    
041        public final void setClosureMonitor( ClosureMonitor monitor )
042        {
043            if ( monitor == null )
044            {
045                throw new NullPointerException( "monitor" );
046            }
047    
048            this.monitor = monitor;
049        }
050    
051    
052        protected final void checkNotClosed( String operation ) throws Exception
053        {
054            monitor.checkNotClosed();
055        }
056    
057    
058        public final boolean isClosed()
059        {
060            return monitor.isClosed();
061        }
062    
063    
064        public void close() throws Exception
065        {
066            monitor.close();
067        }
068    
069    
070        public void close( Exception cause ) throws Exception
071        {
072            monitor.close( cause );
073        }
074    
075    
076        public Iterator<IndexEntry<K, E, ID>> iterator()
077        {
078            return new CursorIterator<IndexEntry<K, E, ID>>( this );
079        }
080    }