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 AbstractTupleCursor<K, V> implements TupleCursor<K, V>
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            this.monitor = monitor;
048        }
049    
050    
051        protected final void checkNotClosed( String operation ) throws Exception
052        {
053            monitor.checkNotClosed();
054        }
055    
056    
057        public final boolean isClosed()
058        {
059            return monitor.isClosed();
060        }
061    
062    
063        public void close() throws Exception
064        {
065            monitor.close();
066        }
067    
068    
069        public void close( Exception cause ) throws Exception
070        {
071            monitor.close( cause );
072        }
073    
074    
075        public Iterator<Tuple<K, V>> iterator()
076        {
077            return new CursorIterator<Tuple<K, V>>( this );
078        }
079    }