Activemq 从Spring批处理步骤内部侦听JMS的最干净的方法是什么？

Spring批处理文档建议使用JmsItemReader，它是JMSTemplate的包装器。但是，我发现JMSTemplate存在一些问题—请参阅

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这篇文章引起我的注意，只是因为队列在我真正读取数据之前就消失了。错过消息的机会对我来说似乎是一个相当重要的问题。

对于消费者来说，至少可以尝试使用DefaultMessageListenerContainer和SingleConnectionFactory或任何类似的连接工厂，它不需要调度程序来唤醒他们。有很多例子可以解释这一点，这一个非常适合解释这些东西

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这是我最终得到的解决方案。由于该查询是关于从spring批处理步骤中侦听JMS的“最干净”的方法，因此我将把这个问题保留一段时间，以防有更好的方法

如果有人能找出代码格式不正确的原因，请告诉我如何修复它

1。在作业侦听器中，分别在作业前和作业后事件中实现队列设置和拆卸：

public void beforeJob(JobExecution jobExecution) {
    try {
        jobParameters = jobExecution.getJobParameters();

        readerConnection = connectionFactory.createConnection();
        readerConnection.start();

    } catch (JMSException ex) {
        // handle the exception as appropriate
    }
}

public void afterJob(JobExecution jobExecution) {
    try {
        readerConnection.close();
    } catch (JMSException e) {
        // handle the exception as appropriate
    }
}

public TreeModel<SelectedDataElementNode> read() throws Exception,
        UnexpectedInputException, ParseException,
        NonTransientResourceException {

    Object result = null;

    logger.debug("Attempting to receive message on connection: ", connection.toString());

    ObjectMessage msg = (ObjectMessage) messageConsumer.receive();
    logger.debug("Received: {}", msg.toString());

    result = msg.getObject();
    return result;
}

<batch:job id="doStuff">
    <batch:listeners>
        <batch:listener ref="jmsJobExecutionListener" />
    </batch:listeners>
... snip ...
            <batch:step id="step0003-do-stuff">
                <batch:tasklet transaction-manager="jtaTransactionManager"
                    start-limit="100">
                    <batch:chunk reader="selectedDataJmsReader" writer="someWriter"
                        commit-interval="1" />
                </batch:tasklet>
                <batch:listeners>
                    <batch:listener ref="selectedDataJmsReader" />
                </batch:listeners>
            </batch:step>
</batch:job>

2。在reader中，实现StepListener和beforeStep/afterStep方法。

public void beforeStep(StepExecution stepExecution) {
    this.stepExecution = stepExecution;
    this.setJobExecution(stepExecution.getJobExecution());
    try {
        this.connection = jmsJobExecutionListener.getReaderConnection();
        this.jmsSession = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
        this.messageConsumer = jmsSession.createConsumer(jmsJobExecutionListener.getQueue());
    }
    catch (JMSException ex)
    {
        // handle the exception as appropriate
    }

}

public ExitStatus afterStep(StepExecution stepExecution) {
    try {
        messageConsumer.close();
        jmsSession.close();
    } catch (JMSException e) {
        // handle the exception as appropriate
    }
    return stepExecution.getExitStatus();
}

3。实现read（）方法：

public void beforeJob(JobExecution jobExecution) {
    try {
        jobParameters = jobExecution.getJobParameters();

        readerConnection = connectionFactory.createConnection();
        readerConnection.start();

    } catch (JMSException ex) {
        // handle the exception as appropriate
    }
}

public void afterJob(JobExecution jobExecution) {
    try {
        readerConnection.close();
    } catch (JMSException e) {
        // handle the exception as appropriate
    }
}

public TreeModel<SelectedDataElementNode> read() throws Exception,
        UnexpectedInputException, ParseException,
        NonTransientResourceException {

    Object result = null;

    logger.debug("Attempting to receive message on connection: ", connection.toString());

    ObjectMessage msg = (ObjectMessage) messageConsumer.receive();
    logger.debug("Received: {}", msg.toString());

    result = msg.getObject();
    return result;
}

<batch:job id="doStuff">
    <batch:listeners>
        <batch:listener ref="jmsJobExecutionListener" />
    </batch:listeners>
... snip ...
            <batch:step id="step0003-do-stuff">
                <batch:tasklet transaction-manager="jtaTransactionManager"
                    start-limit="100">
                    <batch:chunk reader="selectedDataJmsReader" writer="someWriter"
                        commit-interval="1" />
                </batch:tasklet>
                <batch:listeners>
                    <batch:listener ref="selectedDataJmsReader" />
                </batch:listeners>
            </batch:step>
</batch:job>

public TreeModel read（）引发异常，
UnexpectedInputException，ParseException，
非TransientResourceException{
对象结果=空；
debug（“试图在连接上接收消息：”，connection.toString（））；
ObjectMessage msg=（ObjectMessage）messageConsumer.receive（）；
debug（“Received:{}”，msg.toString（））；
结果=msg.getObject（）；
返回结果；
}

4。根据需要将侦听器添加到Spring批处理上下文中：

public void beforeJob(JobExecution jobExecution) {
    try {
        jobParameters = jobExecution.getJobParameters();

        readerConnection = connectionFactory.createConnection();
        readerConnection.start();

    } catch (JMSException ex) {
        // handle the exception as appropriate
    }
}

public void afterJob(JobExecution jobExecution) {
    try {
        readerConnection.close();
    } catch (JMSException e) {
        // handle the exception as appropriate
    }
}

public TreeModel<SelectedDataElementNode> read() throws Exception,
        UnexpectedInputException, ParseException,
        NonTransientResourceException {

    Object result = null;

    logger.debug("Attempting to receive message on connection: ", connection.toString());

    ObjectMessage msg = (ObjectMessage) messageConsumer.receive();
    logger.debug("Received: {}", msg.toString());

    result = msg.getObject();
    return result;
}

<batch:job id="doStuff">
    <batch:listeners>
        <batch:listener ref="jmsJobExecutionListener" />
    </batch:listeners>
... snip ...
            <batch:step id="step0003-do-stuff">
                <batch:tasklet transaction-manager="jtaTransactionManager"
                    start-limit="100">
                    <batch:chunk reader="selectedDataJmsReader" writer="someWriter"
                        commit-interval="1" />
                </batch:tasklet>
                <batch:listeners>
                    <batch:listener ref="selectedDataJmsReader" />
                </batch:listeners>
            </batch:step>
</batch:job>

... 剪

在我看来，这似乎是相关的，因为他报告的症状正是apache post描述的感谢反馈的症状。由于JMSTemplate在这种上下文中肯定会丢失消息，因此没有任何涉及JMSTemplate的解决方案是可行的答案。我不会贬低这个答案，因为我可能仍然遗漏了一些东西。