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 */ 017package org.apache.activemq; 018 019import javax.jms.JMSException; 020import javax.jms.Queue; 021import javax.jms.QueueReceiver; 022 023import org.apache.activemq.command.ActiveMQDestination; 024import org.apache.activemq.command.ConsumerId; 025 026/** 027 * A client uses a <CODE>QueueReceiver</CODE> object to receive messages that 028 * have been delivered to a queue. <p/> 029 * <P> 030 * Although it is possible to have multiple <CODE>QueueReceiver</CODE> s for 031 * the same queue, the JMS API does not define how messages are distributed 032 * between the <CODE>QueueReceiver</CODE>s. <p/> 033 * <P> 034 * If a <CODE>QueueReceiver</CODE> specifies a message selector, the messages 035 * that are not selected remain on the queue. By definition, a message selector 036 * allows a <CODE>QueueReceiver</CODE> to skip messages. This means that when 037 * the skipped messages are eventually read, the total ordering of the reads 038 * does not retain the partial order defined by each message producer. Only 039 * <CODE>QueueReceiver</CODE> s without a message selector will read messages 040 * in message producer order. <p/> 041 * <P> 042 * Creating a <CODE>MessageConsumer</CODE> provides the same features as 043 * creating a <CODE>QueueReceiver</CODE>. A <CODE>MessageConsumer</CODE> 044 * object is recommended for creating new code. The <CODE>QueueReceiver 045 * </CODE> 046 * is provided to support existing code. 047 * 048 * @see javax.jms.Session#createConsumer(javax.jms.Destination, String) 049 * @see javax.jms.Session#createConsumer(javax.jms.Destination) 050 * @see javax.jms.QueueSession#createReceiver(Queue, String) 051 * @see javax.jms.QueueSession#createReceiver(Queue) 052 * @see javax.jms.MessageConsumer 053 */ 054 055public class ActiveMQQueueReceiver extends ActiveMQMessageConsumer implements QueueReceiver { 056 057 /** 058 * @param theSession 059 * @param value 060 * @param destination 061 * @param messageSelector 062 * @param prefetch 063 * @param asyncDispatch 064 * @throws JMSException 065 */ 066 protected ActiveMQQueueReceiver(ActiveMQSession theSession, ConsumerId consumerId, 067 ActiveMQDestination destination, String selector, int prefetch, 068 int maximumPendingMessageCount, boolean asyncDispatch) 069 throws JMSException { 070 super(theSession, consumerId, destination, null, selector, prefetch, maximumPendingMessageCount, 071 false, false, asyncDispatch, null); 072 } 073 074 /** 075 * Gets the <CODE>Queue</CODE> associated with this queue receiver. 076 * 077 * @return this receiver's <CODE>Queue</CODE> 078 * @throws JMSException if the JMS provider fails to get the queue for this 079 * queue receiver due to some internal error. 080 */ 081 082 public Queue getQueue() throws JMSException { 083 checkClosed(); 084 return (Queue)super.getDestination(); 085 } 086 087}