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 */
020package org.apache.directory.api.ldap.model.cursor;
021
022
023/**
024 * A monitor used by Cursors to detect conditions when they should stop 
025 * performing some work during advance operations such as next(), previous(),
026 * first() etc, and release resources.
027 *
028 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
029 */
030public interface ClosureMonitor
031{
032    /**
033     * Sets monitor state to closed, and sets the cause to a 
034     * CursorClosedException without an error message string.
035     */
036    void close();
037
038
039    /**
040     * Sets monitor state to closed, and sets the cause to a 
041     * CursorClosedException with a specific error message string.
042     * 
043     * @param cause error message string
044     */
045    void close( String cause );
046
047
048    /**
049     * Sets monitor state to closed, and sets the cause to a specific 
050     * Exception.
051     * 
052     * @param cause the exception to associate with the closure
053     */
054    void close( Exception cause );
055
056
057    /**
058     * Gets whether the state of this ClosureMonitor is set to closed.
059     *
060     * @return true if state is closed, false if open
061     */
062    boolean isClosed();
063
064
065    /**
066     * Checks if state of this ClosureMonitor is set to closed and if so, 
067     * throws the causing Exception.
068     *
069     * @throws CursorClosedException the cause of the closure
070     */
071    void checkNotClosed() throws CursorClosedException;
072
073
074    /**
075     * Gets the cause of the closure.
076     *
077     * @return the causing Exception
078     */
079    Exception getCause();
080}