001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.activemq.store;
018    
019    import java.io.IOException;
020    import org.apache.activemq.broker.ConnectionContext;
021    import org.apache.activemq.command.ActiveMQDestination;
022    import org.apache.activemq.command.MessageId;
023    import org.apache.activemq.usage.MemoryUsage;
024    
025    abstract public class AbstractMessageStore implements MessageStore {
026        protected final ActiveMQDestination destination;
027    
028        public AbstractMessageStore(ActiveMQDestination destination) {
029            this.destination = destination;
030        }
031    
032        public void dispose(ConnectionContext context) {
033        }
034    
035        public void start() throws Exception {
036        }
037    
038        public void stop() throws Exception {
039        }
040    
041        public ActiveMQDestination getDestination() {
042            return destination;
043        }
044    
045        public void setMemoryUsage(MemoryUsage memoryUsage) {
046        }
047        
048        public void setBatch(MessageId messageId) throws IOException, Exception {
049        }
050        
051        /**
052         * flag to indicate if the store is empty
053         * @return true if the message count is 0
054         * @throws Exception 
055         */
056         public boolean isEmpty() throws Exception{
057             return getMessageCount()==0;
058         }
059    }