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;
018    
019    import java.util.List;
020    import javax.jms.JMSException;
021    import org.apache.activemq.command.MessageDispatch;
022    
023    public interface MessageDispatchChannel {
024    
025        public abstract void enqueue(MessageDispatch message);
026    
027        public abstract void enqueueFirst(MessageDispatch message);
028    
029        public abstract boolean isEmpty();
030    
031        /**
032         * Used to get an enqueued message. The amount of time this method blocks is
033         * based on the timeout value. - if timeout==-1 then it blocks until a
034         * message is received. - if timeout==0 then it it tries to not block at
035         * all, it returns a message if it is available - if timeout>0 then it
036         * blocks up to timeout amount of time. Expired messages will consumed by
037         * this method.
038         * 
039         * @throws JMSException
040         * @return null if we timeout or if the consumer is closed.
041         * @throws InterruptedException
042         */
043        public abstract MessageDispatch dequeue(long timeout) throws InterruptedException;
044    
045        public abstract MessageDispatch dequeueNoWait();
046    
047        public abstract MessageDispatch peek();
048    
049        public abstract void start();
050    
051        public abstract void stop();
052    
053        public abstract void close();
054    
055        public abstract void clear();
056    
057        public abstract boolean isClosed();
058    
059        public abstract int size();
060    
061        public abstract Object getMutex();
062    
063        public abstract boolean isRunning();
064    
065        public abstract List<MessageDispatch> removeAll();
066    
067    }