当通过JMS连接到ActiveMQ Artemis时，我正在努力解决基于Apache Camel的应用程序中的一个问题。在其中一个Camel路由的末尾，消息存储在Artemis JMS队列中。在同一应用程序中运行的遗留组件使用ConsumerTemplate定期从那里获取它们。
这对于带有纯文本正文的Camel消息很有效，但在使用字节数组正文时会导致错误：Artemis似乎将任何带有字节体的消息视为"large message", which are streamed instead of kept in memory。通过ConsumerTemplate接收可以工作，但是一旦访问了body或header，就会引发如下异常：

org.apache.camel.RuntimeCamelException: Failed to extract body due to: javax.jms.IllegalStateException: AMQ119023: The large message lost connection with its session, either because of a rollback or a closed session. Message: ActiveMQMessage[ID:90c4d1d5-3233-11ea-b0cc-44032c68a56f]:PERSISTENT/ClientLargeMessageImpl[messageID=2974, durable=true, address=mytest,userID=90c4d1d5-3233-11ea-b0cc-44032c68a56f,properties=TypedProperties[firedTime=Wed Jan 08 17:26:03 CET 2020,__AMQ_CID=90b4f34e-3233-11ea-b0cc-44032c68a56f,breadcrumbId=ID-NB045-evolit-co-at-1578500762151-0-1,_AMQ_ROUTING_TYPE=1,_AMQ_LARGE_SIZE=3]]
        at org.apache.camel.component.jms.JmsBinding.extractBodyFromJms(JmsBinding.java:172) ~[camel-jms-2.22.1.jar:2.22.1]
        at org.apache.camel.component.jms.JmsMessage.createBody(JmsMessage.java:221) ~[camel-jms-2.22.1.jar:2.22.1]
        at org.apache.camel.impl.MessageSupport.getBody(MessageSupport.java:54) ~[camel-core-2.22.1.jar:2.22.1]
        at org.apache.camel.example.cdi.JmsPoller.someMethod(JmsPoller.java:36) ~[classes/:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_171]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_171]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_171]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_171]
        at org.apache.camel.component.bean.MethodInfo.invoke(MethodInfo.java:481) ~[camel-core-2.22.1.jar:2.22.1]
        at org.apache.camel.component.bean.MethodInfo$1.doProceed(MethodInfo.java:300) ~[camel-core-2.22.1.jar:2.22.1]
        at org.apache.camel.component.bean.MethodInfo$1.proceed(MethodInfo.java:273) ~[camel-core-2.22.1.jar:2.22.1]
        at org.apache.camel.component.bean.AbstractBeanProcessor.process(AbstractBeanProcessor.java:188) ~[camel-core-2.22.1.jar:2.22.1]
        at org.apache.camel.component.bean.BeanProcessor.process(BeanProcessor.java:53) ~[camel-core-2.22.1.jar:2.22.1]
        at org.apache.camel.component.bean.BeanProducer.process(BeanProducer.java:41) ~[camel-core-2.22.1.jar:2.22.1]
        at org.apache.camel.processor.SendProcessor.process(SendProcessor.java:148) ~[camel-core-2.22.1.jar:2.22.1]
        at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:548) [camel-core-2.22.1.jar:2.22.1]
        at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:201) [camel-core-2.22.1.jar:2.22.1]
        at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:201) [camel-core-2.22.1.jar:2.22.1]
        at org.apache.camel.component.timer.TimerConsumer.sendTimerExchange(TimerConsumer.java:197) [camel-core-2.22.1.jar:2.22.1]
        at org.apache.camel.component.timer.TimerConsumer$1.run(TimerConsumer.java:79) [camel-core-2.22.1.jar:2.22.1]
        at java.util.TimerThread.mainLoop(Timer.java:555) [?:1.8.0_171]
        at java.util.TimerThread.run(Timer.java:505) [?:1.8.0_171]
Caused by: javax.jms.IllegalStateException: AMQ119023: The large message lost connection with its session, either because of a rollback or a closed session
        at org.apache.activemq.artemis.core.client.impl.LargeMessageControllerImpl.saveBuffer(LargeMessageControllerImpl.java:273) ~[artemis-core-client-2.6.2.jar:2.6.2]
        at org.apache.activemq.artemis.core.client.impl.ClientLargeMessageImpl.saveToOutputStream(ClientLargeMessageImpl.java:115) ~[artemis-core-client-2.6.2.jar:2.6.2]
        at org.apache.activemq.artemis.jms.client.ActiveMQMessage.saveToOutputStream(ActiveMQMessage.java:853) ~[artemis-jms-client-2.6.2.jar:2.6.2]
        at org.apache.activemq.artemis.jms.client.ActiveMQMessage.setObjectProperty(ActiveMQMessage.java:693) ~[artemis-jms-client-2.6.2.jar:2.6.2]
        at org.apache.camel.component.jms.JmsBinding.createByteArrayFromBytesMessage(JmsBinding.java:251) ~[camel-jms-2.22.1.jar:2.22.1]
        at org.apache.camel.component.jms.JmsBinding.extractBodyFromJms(JmsBinding.java:163) ~[camel-jms-2.22.1.jar:2.22.1]
        ... 21 more
Caused by: org.apache.activemq.artemis.api.core.ActiveMQIllegalStateException: AMQ119023: The large message lost connection with its session, either because of a rollback or a closed session
        at org.apache.activemq.artemis.core.client.impl.LargeMessageControllerImpl.saveBuffer(LargeMessageControllerImpl.java:273) ~[artemis-core-client-2.6.2.jar:2.6.2]
        at org.apache.activemq.artemis.core.client.impl.ClientLargeMessageImpl.saveToOutputStream(ClientLargeMessageImpl.java:115) ~[artemis-core-client-2.6.2.jar:2.6.2]
        at org.apache.activemq.artemis.jms.client.ActiveMQMessage.saveToOutputStream(ActiveMQMessage.java:853) ~[artemis-jms-client-2.6.2.jar:2.6.2]
        at org.apache.activemq.artemis.jms.client.ActiveMQMessage.setObjectProperty(ActiveMQMessage.java:693) ~[artemis-jms-client-2.6.2.jar:2.6.2]
        at org.apache.camel.component.jms.JmsBinding.createByteArrayFromBytesMessage(JmsBinding.java:251) ~[camel-jms-2.22.1.jar:2.22.1]
        at org.apache.camel.component.jms.JmsBinding.extractBodyFromJms(JmsBinding.java:163) ~[camel-jms-2.22.1.jar:2.22.1]
        ... 21 more

这个问题也发生在不超过Artemis的minLargeMessageSize的消息中，在测试程序中甚至是3字节。
巧合的是，同样的问题也发生在用于测试应用程序的独立应用程序中。在那里，我能够通过保持JMS会话和接收器打开直到JMS消息体和消息头被完全读取来解决这个问题。对于Camel，这在Camel所基于的Spring JmsTemplate中被抽象掉了。
我咨询了user documentation of the Camel JMS component来寻找可能对我有帮助的配置选项。我尝试了以下方法：

• eagerLoadingOfProperties=true在消费者端：没有影响，似乎只影响MessageListenerContainer。该文档说：

它使用Spring的JmsTemplate进行发送，使用MessageListenerContainer进行消费。
但是，在调试时，似乎只有在使用来自Camel路由中的JMS端点的消息时才使用MessageListenerContainer。使用ConsumerTemplate，就像我的例子一样，使用JmsTemplate进行消费。

• 消费者端messageConverter和mapJmsMessage：无效，它们在会话已关闭时执行
• alwaysCopyMessage在生产者端：我想也许复制可以防止使用流式传输的大消息，没有效果
• 生产者端streamMessageTypeEnabled=false：没有影响
• jmsMessageType=Bytes在生产者和消费者方面：没有影响
• transferExchange=true在生产者和消费者方面：这似乎解决了我的具体情况，但它感觉像一个变通办法。文档建议谨慎使用该选项。

所以现在，transferExchange似乎是我最好的选择，假设它在所有测试用例中都能解决我的问题。尽管如此，我还是很高兴能更好地了解这个问题或不同的解决方案：
1.为什么阿耳忒弥斯把小字节数组消息当作大消息？

1. Camel ConsumerTemplate是否支持流式的大消息？
   我的版本是Camel 2.22.1和Artemis 2.10.1。
   通过修改Camel发布包中的Camel Example camel-example-cdi，我已经能够重现我的问题，使其具有如下所示的最小类。此外，我还添加了camel-jms和Artemis依赖项，并在本地启动了Artemis，两者都与camel-example-artemis-large-messages示例中描述的一样。

public class MyRoutes extends RouteBuilder {

    @Override
    public void configure() {
        setupJmsComponent();

        from("timer:writeTimer?period=6000")
                .log("writing to JMS")
                .setBody(() -> new byte[]{0,1,2})
                .to(JmsPoller.ENDPOINT);

        from("timer:pollTimer?period=3000")
            .to("bean:jmsPoller");
    }

    private void setupJmsComponent() {
        ActiveMQJMSConnectionFactory connectionFactory = new ActiveMQJMSConnectionFactory("tcp://localhost:61616");
        JmsComponent jmsComponent = new JmsComponent();
        jmsComponent.setConnectionFactory(connectionFactory);
        getContext().addComponent("jms", jmsComponent);
    }

}

@Singleton
@Named("jmsPoller")
public class JmsPoller {
    static final String ENDPOINT = "jms:queue:mytest";

    @Inject
    private ConsumerTemplate consumerTemplate;

    public void someMethod(String body) {
        Exchange exchange = consumerTemplate.receive(ENDPOINT, 1000L);
        System.out.println("Received " + (exchange == null ? null : exchange.getIn().getBody()));
    }

}