Apache Camel - 错误处理问题

Question

我遇到了错误处理问题。如果jrnRoute 发生异常，则由exceptionHandler 处理器处理。还行吧。但是导致异常的消息仍然保留在jrnQueue 中，被再次处理并一遍又一遍地导致错误。此外，我在日志中有一个警告（见下文）。如何阻止无限重发？如果出现错误，我想扔掉一条消息。

Camel configuration

    <camel:onException>
        <camel:exception>java.lang.Exception</camel:exception>
        <camel:redeliveryPolicy disableRedelivery="true" />
        <camel:process ref="exceptionHandler" />
        <camel:rollback markRollbackOnly="true" />
    </camel:onException>

    <camel:route id="translatorRoute">
        <camel:from ref="transactionsQueue" />
        <camel:process ref="messageTranslator" />
        <camel:inOnly ref="apfRequestQueue" />
    </camel:route>
    <camel:route id="jrnRoute">
        <camel:from ref="jrnQueue" />
        <camel:process ref="jrnProcessor" />
        <camel:stop />
    </camel:route>
</camel:camelContext>

Warning

11:15:00,141 WARN  [JmsMessageListenerContainer] Execution of JMS message listener failed, and no ErrorHandler has been set.
org.apache.camel.RuntimeCamelException: org.apache.camel.RollbackExchangeException: Intended rollback. Exchange[JmsMessage: [ObjectMessageImpl com.swiftmq.jms.ObjectMessageImpl@c84d9d
messageIndex = 5_2
messageId = [LazyUTF8String, s=ID:/172.26.214.11/5349789614428334512/10/0, buffer=[B@5f7fd8]
userId = [LazyUTF8String, s=null, buffer=[B@1c254aa]
clientId = null
timeStamp = 1316682898526
correlationId = null
replyTo = null
destination = jrnQueue@z4smq_4001
deliveryMode = 2
redelivered = true
deliveryCount = 8
type = null
expiration = 0
priority = 4
props = {...}
readOnly = true
sourceRouter = null
destRouter = null
destQueue = null array=[B@1447e6b cnt=1295]]
    at org.apache.camel.util.ObjectHelper.wrapRuntimeCamelException(ObjectHelper.java:1145)
    at org.apache.camel.component.jms.EndpointMessageListener.onMessage(EndpointMessageListener.java:108)
    at org.springframework.jms.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:560)
    at org.springframework.jms.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:498)
    at org.springframework.jms.listener.AbstractMessageListenerContainer.doExecuteListener(AbstractMessageListenerContainer.java:467)
    at org.springframework.jms.listener.AbstractPollingMessageListenerContainer.doReceiveAndExecute(AbstractPollingMessageListenerContainer.java:325)
    at org.springframework.jms.listener.AbstractPollingMessageListenerContainer.receiveAndExecute(AbstractPollingMessageListenerContainer.java:243)
    at org.springframework.jms.listener.DefaultMessageListenerContainer$AsyncMessageListenerInvoker.invokeListener(DefaultMessageListenerContainer.java:1058)
    at org.springframework.jms.listener.DefaultMessageListenerContainer$AsyncMessageListenerInvoker.executeOngoingLoop(DefaultMessageListenerContainer.java:1050)
    at org.springframework.jms.listener.DefaultMessageListenerContainer$AsyncMessageListenerInvoker.run(DefaultMessageListenerContainer.java:947)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)
Caused by: org.apache.camel.RollbackExchangeException: Intended rollback. Exchange[JmsMessage: [ObjectMessageImpl com.swiftmq.jms.ObjectMessageImpl@c84d9d
messageIndex = 5_2
messageId = [LazyUTF8String, s=ID:/172.26.214.11/5349789614428334512/10/0, buffer=[B@5f7fd8]
userId = [LazyUTF8String, s=null, buffer=[B@1c254aa]
clientId = null
timeStamp = 1316682898526
correlationId = null
replyTo = null
destination = jrnQueue@z4smq_4001
deliveryMode = 2
redelivered = true
deliveryCount = 8
type = null
expiration = 0
priority = 4
props = {...}
readOnly = true
sourceRouter = null
destRouter = null
destQueue = null array=[B@1447e6b cnt=1295]]

Answer 1

看起来markRollbackOnly="true" 是问题所在......

我通常会做这样的事情来简单地处理（防止传播回调用者）、防止重试和记录错误消息...

onException(Exception.class)
    .handled(true).maximumRedeliveries(0)
    .to("log:error processing message");

Answer 2

是的，markRollbackOnly 将导致事务管理器将 TX 标记为回滚，因此 JMS 代理会将消息保留在队列中，然后再次重新传递。所以删除它。

按照上面 Ben 发布的方法进行操作，处理为 true：

 <camel:onException>
        <camel:exception>java.lang.Exception</camel:exception>
        <camel:redeliveryPolicy disableRedelivery="true" />
        <camel:handled>
            <camel:constant>true</camel:constant>
        </camel:handled>

        <camel:process ref="exceptionHandler" />
 </camel:onException>