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    package org.apache.directory.shared.ldap.cursor;
020    
021    
022    import java.util.Iterator;
023    
024    import org.apache.directory.shared.i18n.I18n;
025    
026    
027    /**
028     * Simple class that contains often used Cursor code.
029     *
030     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
031     * @version $Rev$, $Date$
032     */
033    public abstract class AbstractCursor<E> implements Cursor<E>
034    {
035        /** The default associated monitor */
036        private ClosureMonitor monitor = new DefaultClosureMonitor();
037    
038        /**
039         * {@inheritDoc}
040         */
041        public final void setClosureMonitor( ClosureMonitor monitor )
042        {
043            if ( monitor == null )
044            {
045                throw new NullPointerException( I18n.err( I18n.ERR_02001 ) );
046            }
047            
048            this.monitor = monitor;
049        }
050        
051    
052        /**
053         * Check that the cursor is not closed.
054         * 
055         * @param operation
056         * @throws Exception
057         */
058        protected final void checkNotClosed( String operation ) throws Exception
059        {
060            monitor.checkNotClosed();
061        }
062    
063    
064        /**
065         * {@inheritDoc}
066         */
067        public final boolean isClosed()
068        {
069            return monitor.isClosed();
070        }
071    
072    
073        /**
074         * {@inheritDoc}
075         */
076        public void close( Exception cause ) throws Exception
077        {
078            monitor.close( cause );
079        }
080    
081    
082        /**
083         * {@inheritDoc}
084         */
085        public void close() throws Exception
086        {
087            monitor.close();
088        }
089    
090    
091        /**
092         * {@inheritDoc}
093         */
094        public Iterator<E> iterator()
095        {
096            return new CursorIterator<E>( this );
097        }
098    }