001 /** 002 * 003 * Copyright 2004 Protique Ltd 004 * 005 * Licensed under the Apache License, Version 2.0 (the "License"); 006 * you may not use this file except in compliance with the License. 007 * 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 **/ 018 019 package org.activemq; 020 021 import org.activemq.message.ActiveMQDestination; 022 023 import javax.jms.JMSException; 024 import javax.jms.Queue; 025 import javax.jms.QueueReceiver; 026 027 /** 028 * A client uses a <CODE>QueueReceiver</CODE> object to receive messages that 029 * have been delivered to a queue. 030 * <p/> 031 * <P> 032 * Although it is possible to have multiple <CODE>QueueReceiver</CODE> s for 033 * the same queue, the JMS API does not define how messages are distributed 034 * between the <CODE>QueueReceiver</CODE>s. 035 * <p/> 036 * <P> 037 * If a <CODE>QueueReceiver</CODE> specifies a message selector, the messages 038 * that are not selected remain on the queue. By definition, a message selector 039 * allows a <CODE>QueueReceiver</CODE> to skip messages. This means that when 040 * the skipped messages are eventually read, the total ordering of the reads 041 * does not retain the partial order defined by each message producer. Only 042 * <CODE>QueueReceiver</CODE> s without a message selector will read messages 043 * in message producer order. 044 * <p/> 045 * <P> 046 * Creating a <CODE>MessageConsumer</CODE> provides the same features as 047 * creating a <CODE>QueueReceiver</CODE>. A <CODE>MessageConsumer</CODE> 048 * object is recommended for creating new code. The <CODE>QueueReceiver 049 * </CODE> is provided to support existing code. 050 * 051 * @see javax.jms.Session#createConsumer(javax.jms.Destination, String) 052 * @see javax.jms.Session#createConsumer(javax.jms.Destination) 053 * @see javax.jms.QueueSession#createReceiver(Queue, String) 054 * @see javax.jms.QueueSession#createReceiver(Queue) 055 * @see javax.jms.MessageConsumer 056 */ 057 058 public class ActiveMQQueueReceiver extends ActiveMQMessageConsumer implements 059 QueueReceiver { 060 061 /** 062 * @param theSession 063 * @param dest 064 * @param selector 065 * @param cnum 066 * @param prefetch 067 * @throws JMSException 068 */ 069 protected ActiveMQQueueReceiver(ActiveMQSession theSession, 070 ActiveMQDestination dest, String selector, int cnum, int prefetch) 071 throws JMSException { 072 super(theSession, dest, "", selector, cnum, prefetch, false, false); 073 } 074 075 /** 076 * Gets the <CODE>Queue</CODE> associated with this queue receiver. 077 * 078 * @return this receiver's <CODE>Queue</CODE> 079 * @throws JMSException if the JMS provider fails to get the queue for this queue 080 * receiver due to some internal error. 081 */ 082 083 public Queue getQueue() throws JMSException { 084 checkClosed(); 085 return (Queue) super.getDestination(); 086 } 087 }