深入掌握JMS（七）：DeliveryMode例子 (转)

在下面的例子中，分别发送一个Persistent和nonpersistent的消息，然后关闭退出JMS。

import javax.jms.Connection;
import javax.jms.DeliveryMode;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.Session;
import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.command.ActiveMQQueue;
public class DeliveryModeSendTest {
    public static void main(String[] args) throws Exception {
        ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory("vm://localhost");
   
        Connection connection = factory.createConnection();
        connection.start();
       
        Queue queue = new ActiveMQQueue("testQueue");
        Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
               
        MessageProducer producer = session.createProducer(queue);
        producer.setDeliveryMode(DeliveryMode.PERSISTENT);
        producer.send(session.createTextMessage("A persistent Message"));
       
        producer.setDeliveryMode(DeliveryMode.NON_PERSISTENT);
        producer.send(session.createTextMessage("A non persistent Message"));
       
        System.out.println("Send messages sucessfully!");
    }
}

 运行上面的程序，当输出“Send messages sucessfully!”时，说明两个消息都已经发送成功，然后我们结束它，来停止JMS Provider。
接下来我们重新启动JMS Provicer，然后添加一个消费者：

import javax.jms.Connection;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageListener;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.command.ActiveMQQueue;
public class DeliveryModeReceiveTest {
    public static void main(String[] args) throws Exception {
        ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory("vm://localhost");
   
        Connection connection = factory.createConnection();
        connection.start();
       
        Queue queue = new ActiveMQQueue("testQueue");
        Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
       
        MessageConsumer comsumer = session.createConsumer(queue);
        comsumer.setMessageListener(new MessageListener(){
            public void onMessage(Message m) {
                try {
                    System.out.println("Consumer get " + ((TextMessage)m).getText());
                } catch (JMSException e) {
                    e.printStackTrace();
                }
            }
        });
    }
}

 运行上面的程序，可以得到下面的输出结果：

Consumer get A persistent Message

可以看出消息消费者只接收到一个消息，它是一个Persistent的消息。而刚才发送的non persistent消息已经丢失了。

另外, 如果发送一个non persistent消息, 而刚好这个时候没有消费者在监听, 这个消息也会丢失.

评论

1 楼 hyneng 2011-05-05  

运行第二个例子有错

org.apache.activemq.protobuf.InvalidProtocolBufferException: Protocol message end-group tag did not match expected tag.
	at org.apache.activemq.protobuf.InvalidProtocolBufferException.invalidEndTag(InvalidProtocolBufferException.java:52)
	at org.apache.activemq.protobuf.CodedInputStream.checkLastTagWas(CodedInputStream.java:95)
	at org.apache.activemq.protobuf.BaseMessage.mergeUnframed(BaseMessage.java:185)
	at org.apache.activemq.protobuf.BaseMessage.mergeUnframed(BaseMessage.java:213)
	at org.apache.activemq.protobuf.BaseMessage.mergeFramed(BaseMessage.java:237)
	at org.apache.activemq.store.kahadb.MessageDatabase.load(MessageDatabase.java:825)
	at org.apache.activemq.store.kahadb.KahaDBStore.loadMessage(KahaDBStore.java:955)
	at org.apache.activemq.store.kahadb.KahaDBStore$KahaDBMessageStore$5.execute(KahaDBStore.java:493)
	at org.apache.kahadb.page.Transaction.execute(Transaction.java:728)
	at org.apache.activemq.store.kahadb.KahaDBStore$KahaDBMessageStore.recoverNextMessages(KahaDBStore.java:485)
	at org.apache.activemq.store.ProxyMessageStore.recoverNextMessages(ProxyMessageStore.java:88)
	at org.apache.activemq.broker.region.cursors.QueueStorePrefetch.doFillBatch(QueueStorePrefetch.java:97)
	at org.apache.activemq.broker.region.cursors.AbstractStoreCursor.fillBatch(AbstractStoreCursor.java:260)
	at org.apache.activemq.broker.region.cursors.AbstractStoreCursor.reset(AbstractStoreCursor.java:108)
	at org.apache.activemq.broker.region.cursors.StoreQueueCursor.reset(StoreQueueCursor.java:157)
	at org.apache.activemq.broker.region.Queue.doPageInForDispatch(Queue.java:1712)
	at org.apache.activemq.broker.region.Queue.pageInMessages(Queue.java:1932)
	at org.apache.activemq.broker.region.Queue.iterate(Queue.java:1440)
	at org.apache.activemq.thread.PooledTaskRunner.runTask(PooledTaskRunner.java:127)
	at org.apache.activemq.thread.PooledTaskRunner$1.run(PooledTaskRunner.java:48)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:619)
1593 [BrokerService[localhost] Task-1] ERROR org.apache.activemq.broker.region.cursors.AbstractStoreCursor - QueueStorePrefetch2569862 - Failed to fill batch
java.lang.RuntimeException: org.apache.activemq.protobuf.InvalidProtocolBufferException: Protocol message end-group tag did not match expected tag.
	at org.apache.activemq.broker.region.cursors.AbstractStoreCursor.fillBatch(AbstractStoreCursor.java:263)
	at org.apache.activemq.broker.region.cursors.AbstractStoreCursor.reset(AbstractStoreCursor.java:108)
	at org.apache.activemq.broker.region.cursors.StoreQueueCursor.reset(StoreQueueCursor.java:157)
	at org.apache.activemq.broker.region.Queue.doPageInForDispatch(Queue.java:1712)
	at org.apache.activemq.broker.region.Queue.pageInMessages(Queue.java:1932)
	at org.apache.activemq.broker.region.Queue.iterate(Queue.java:1440)
	at org.apache.activemq.thread.PooledTaskRunner.runTask(PooledTaskRunner.java:127)
	at org.apache.activemq.thread.PooledTaskRunner$1.run(PooledTaskRunner.java:48)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:619)
Caused by: org.apache.activemq.protobuf.InvalidProtocolBufferException: Protocol message end-group tag did not match expected tag.
	at org.apache.activemq.protobuf.InvalidProtocolBufferException.invalidEndTag(InvalidProtocolBufferException.java:52)
	at org.apache.activemq.protobuf.CodedInputStream.checkLastTagWas(CodedInputStream.java:95)
	at org.apache.activemq.protobuf.BaseMessage.mergeUnframed(BaseMessage.java:185)
	at org.apache.activemq.protobuf.BaseMessage.mergeUnframed(BaseMessage.java:213)
	at org.apache.activemq.protobuf.BaseMessage.mergeFramed(BaseMessage.java:237)
	at org.apache.activemq.store.kahadb.MessageDatabase.load(MessageDatabase.java:825)
	at org.apache.activemq.store.kahadb.KahaDBStore.loadMessage(KahaDBStore.java:955)
	at org.apache.activemq.store.kahadb.KahaDBStore$KahaDBMessageStore$5.execute(KahaDBStore.java:493)
	at org.apache.kahadb.page.Transaction.execute(Transaction.java:728)
	at org.apache.activemq.store.kahadb.KahaDBStore$KahaDBMessageStore.recoverNextMessages(KahaDBStore.java:485)
	at org.apache.activemq.store.ProxyMessageStore.recoverNextMessages(ProxyMessageStore.java:88)
	at org.apache.activemq.broker.region.cursors.QueueStorePrefetch.doFillBatch(QueueStorePrefetch.java:97)
	at org.apache.activemq.broker.region.cursors.AbstractStoreCursor.fillBatch(AbstractStoreCursor.java:260)
	... 10 more
1593 [BrokerService[localhost] Task-1] ERROR org.apache.activemq.broker.region.Queue - Failed to page in more queue messages 
java.lang.RuntimeException: java.lang.RuntimeException: org.apache.activemq.protobuf.InvalidProtocolBufferException: Protocol message end-group tag did not match expected tag.
	at org.apache.activemq.broker.region.cursors.AbstractStoreCursor.reset(AbstractStoreCursor.java:111)
	at org.apache.activemq.broker.region.cursors.StoreQueueCursor.reset(StoreQueueCursor.java:157)
	at org.apache.activemq.broker.region.Queue.doPageInForDispatch(Queue.java:1712)
	at org.apache.activemq.broker.region.Queue.pageInMessages(Queue.java:1932)
	at org.apache.activemq.broker.region.Queue.iterate(Queue.java:1440)
	at org.apache.activemq.thread.PooledTaskRunner.runTask(PooledTaskRunner.java:127)
	at org.apache.activemq.thread.PooledTaskRunner$1.run(PooledTaskRunner.java:48)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.RuntimeException: org.apache.activemq.protobuf.InvalidProtocolBufferException: Protocol message end-group tag did not match expected tag.
	at org.apache.activemq.broker.region.cursors.AbstractStoreCursor.fillBatch(AbstractStoreCursor.java:263)
	at org.apache.activemq.broker.region.cursors.AbstractStoreCursor.reset(AbstractStoreCursor.java:108)
	... 9 more
Caused by: org.apache.activemq.protobuf.InvalidProtocolBufferException: Protocol message end-group tag did not match expected tag.
	at org.apache.activemq.protobuf.InvalidProtocolBufferException.invalidEndTag(InvalidProtocolBufferException.java:52)
	at org.apache.activemq.protobuf.CodedInputStream.checkLastTagWas(CodedInputStream.java:95)
	at org.apache.activemq.protobuf.BaseMessage.mergeUnframed(BaseMessage.java:185)
	at org.apache.activemq.protobuf.BaseMessage.mergeUnframed(BaseMessage.java:213)
	at org.apache.activemq.protobuf.BaseMessage.mergeFramed(BaseMessage.java:237)
	at org.apache.activemq.store.kahadb.MessageDatabase.load(MessageDatabase.java:825)
	at org.apache.activemq.store.kahadb.KahaDBStore.loadMessage(KahaDBStore.java:955)
	at org.apache.activemq.store.kahadb.KahaDBStore$KahaDBMessageStore$5.execute(KahaDBStore.java:493)
	at org.apache.kahadb.page.Transaction.execute(Transaction.java:728)
	at org.apache.activemq.store.kahadb.KahaDBStore$KahaDBMessageStore.recoverNextMessages(KahaDBStore.java:485)
	at org.apache.activemq.store.ProxyMessageStore.recoverNextMessages(ProxyMessageStore.java:88)
	at org.apache.activemq.broker.region.cursors.QueueStorePrefetch.doFillBatch(QueueStorePrefetch.java:97)
	at org.apache.activemq.broker.region.cursors.AbstractStoreCursor.fillBatch(AbstractStoreCursor.java:260)
	... 10 more