Question

我一直在使用JMS和ActiveMQ。一切都在创造奇迹。我不是在使用春天，也不是。

界面javax.jms.MessageListener只有一种方法onMessage。在实现中，有可能抛出异常。如果事实上抛出异常，那么我说消息没有正确处理，需要重新尝试。所以，我需要ActiveMQ等待一段时间，然后重试。即我需要抛出异常来回滚JMS事务。

我怎样才能完成这样的行为？

也许ActiveMQ中有一些我无法找到的配置。

或者......也许可以取消向消费者注册MessageListener并自己消费消息，如下所示：

while (true) {
    // ... some administrative stuff like ...
    session = connection.createSesstion(true, SESSION_TRANSACTED)
    try {
        Message m = receiver.receive(queue, 1000L);
        theMessageListener.onMessage(m);
        session.commit();
    } catch (Exception e) {
        session.rollback();
        Thread.sleep(someTimeDefinedSomewhereElse);
    }
    // ... some more administrative stuff
}

在几个线程中，而不是注册监听器。

或者......我可以用某种方式装饰/ AOP /字节操纵MessageListener来自己做。

你会采取什么途径？为什么？

注意：我无法完全控制MessageListener代码。

修改的对概念证明的测试：

@Test
@Ignore("Interactive test, just a proof of concept")
public void transaccionConListener() throws Exception {
    final AtomicInteger atomicInteger = new AtomicInteger(0);

    BrokerService brokerService = new BrokerService();

    String bindAddress = "vm://localhost";
    brokerService.addConnector(bindAddress);
    brokerService.setPersistenceAdapter(new MemoryPersistenceAdapter());
    brokerService.setUseJmx(false);
    brokerService.start();

    ActiveMQConnectionFactory activeMQConnectionFactory = new ActiveMQConnectionFactory(bindAddress);
    RedeliveryPolicy redeliveryPolicy = new RedeliveryPolicy();
    redeliveryPolicy.setInitialRedeliveryDelay(500);
    redeliveryPolicy.setBackOffMultiplier(2);
    redeliveryPolicy.setUseExponentialBackOff(true);
    redeliveryPolicy.setMaximumRedeliveries(2);

    activeMQConnectionFactory.setRedeliveryPolicy(redeliveryPolicy);
    activeMQConnectionFactory.setUseRetroactiveConsumer(true);
    activeMQConnectionFactory.setClientIDPrefix("ID");
    PooledConnectionFactory pooledConnectionFactory = new PooledConnectionFactory(activeMQConnectionFactory);

    pooledConnectionFactory.start();

    Connection connection = pooledConnectionFactory.createConnection();
    Session session = connection.createSession(false, Session.DUPS_OK_ACKNOWLEDGE);
    Queue helloQueue = session.createQueue("Hello");
    MessageConsumer consumer = session.createConsumer(helloQueue);
    consumer.setMessageListener(new MessageListener() {

        @Override
        public void onMessage(Message message) {
            TextMessage textMessage = (TextMessage) message;
            try {
                switch (atomicInteger.getAndIncrement()) {
                    case 0:
                        System.out.println("OK, first message received " + textMessage.getText());
                        message.acknowledge();
                        break;
                    case 1:
                        System.out.println("NOPE, second must be retried " + textMessage.getText());
                        throw new RuntimeException("I failed, aaaaah");
                    case 2:
                        System.out.println("OK, second message received " + textMessage.getText());
                        message.acknowledge();
                }
            } catch (JMSException e) {
                e.printStackTrace(System.out);
            }
        }
    });
    connection.start();

    {
        // A client sends two messages...
        Connection connection1 = pooledConnectionFactory.createConnection();
        Session session1 = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
        connection1.start();

        MessageProducer producer = session1.createProducer(helloQueue);
        producer.send(session1.createTextMessage("Hello World 1"));
        producer.send(session1.createTextMessage("Hello World 2"));

        producer.close();
        session1.close();
        connection1.stop();
        connection1.close();
    }
    JOptionPane.showInputDialog("I will wait, you watch the log...");

    consumer.close();
    session.close();
    connection.stop();
    connection.close();
    pooledConnectionFactory.stop();

    brokerService.stop();

    assertEquals(3, atomicInteger.get());
}

Answer 1

如果您想使用SESSION_TRANSACTED作为确认模式，则需要设置RedeliveryPolicy on your Connection/ConnectionFactory。 This page on ActiveMQ's website还包含一些您可能需要做的好信息。

由于您没有使用Spring，您可以使用类似于以下代码的内容设置RedeliveryPolicy（取自以上链接之一）：

RedeliveryPolicy policy = connection.getRedeliveryPolicy();
policy.setInitialRedeliveryDelay(500);
policy.setBackOffMultiplier(2);
policy.setUseExponentialBackOff(true);
policy.setMaximumRedeliveries(2);

修改将您的代码段添加到答案中，以下显示了它如何与事务一起使用。使用注释掉的Session.rollback（）方法尝试此代码，您将看到使用SESION_TRANSACTED和Session.commit / rollback按预期工作：

@Test public void test() throws Exception { final AtomicInteger atomicInteger = new AtomicInteger(0); BrokerService brokerService = new BrokerService(); String bindAddress = "vm://localhost"; brokerService.addConnector(bindAddress); brokerService.setPersistenceAdapter(new MemoryPersistenceAdapter()); brokerService.setUseJmx(false); brokerService.start(); ActiveMQConnectionFactory activeMQConnectionFactory = new ActiveMQConnectionFactory(bindAddress); RedeliveryPolicy redeliveryPolicy = new RedeliveryPolicy(); redeliveryPolicy.setInitialRedeliveryDelay(500); redeliveryPolicy.setBackOffMultiplier(2); redeliveryPolicy.setUseExponentialBackOff(true); redeliveryPolicy.setMaximumRedeliveries(2); activeMQConnectionFactory.setRedeliveryPolicy(redeliveryPolicy); activeMQConnectionFactory.setUseRetroactiveConsumer(true); activeMQConnectionFactory.setClientIDPrefix("ID"); PooledConnectionFactory pooledConnectionFactory = new PooledConnectionFactory(activeMQConnectionFactory); pooledConnectionFactory.start(); Connection connection = pooledConnectionFactory.createConnection(); final Session session = connection.createSession(true, Session.SESSION_TRANSACTED); Queue helloQueue = session.createQueue("Hello"); MessageConsumer consumer = session.createConsumer(helloQueue); consumer.setMessageListener(new MessageListener() { public void onMessage(Message message) { TextMessage textMessage = (TextMessage) message; try { switch (atomicInteger.getAndIncrement()) { case 0: System.out.println("OK, first message received " + textMessage.getText()); session.commit(); break; case 1: System.out.println("NOPE, second must be retried " + textMessage.getText()); session.rollback(); throw new RuntimeException("I failed, aaaaah"); case 2: System.out.println("OK, second message received " + textMessage.getText()); session.commit(); } } catch (JMSException e) { e.printStackTrace(System.out); } } }); connection.start(); { // A client sends two messages... Connection connection1 = pooledConnectionFactory.createConnection(); Session session1 = connection.createSession(false, Session.AUTO_ACKNOWLEDGE); connection1.start(); MessageProducer producer = session1.createProducer(helloQueue); producer.send(session1.createTextMessage("Hello World 1")); producer.send(session1.createTextMessage("Hello World 2")); producer.close(); session1.close(); connection1.stop(); connection1.close(); } JOptionPane.showInputDialog("I will wait, you watch the log..."); consumer.close(); session.close(); connection.stop(); connection.close(); pooledConnectionFactory.stop(); assertEquals(3, atomicInteger.get()); }

}

Answer 2

您需要将确认模式设置为Session.CLIENT_ACKNOWLEDGE，客户端通过调用消息的确认方法来确认消费消息。

QueueSession session = connection.createQueueSession(false, Session.CLIENT_ACKNOWLEDGE);

然后，在处理消息之后需要调用Message.acknowledge（）方法以删除该消息。

Message message = ...;
// Processing message

message.acknowledge();

Answer 3

如果你的会话是交易的，那么＆＃34;确认模式＆＃34;无论如何都会被忽略。所以，只需让会话处理并使用session.rollback和session.commit提交或回滚您的交易。

从JMS MessageListener发出回滚信号

3 个答案: