Java NullPointerException 与截断的堆栈跟踪

Question

我的 RabbitMQ 监听器出现以下故障。我使用 Spring Boot 1.4.1 和 Spring Integration 4.3.3 (带有 spring-boot-starter-amqp 和 spring-integration-amqp)。我还使用 RabbitMQ 3.5.7。

少量消息会在大量流量下随机出现问题(到目前为止在本地重现该问题并不走运)。

令我困惑的是，堆栈跟踪并不指向我的应用程序，而只是指向框架。下面我附上完整的堆栈跟踪。这是 spring、rabbitMQ 驱动程序还是服务器中的错误？

2017-05-02 10:38:42.337 [501de2ff-cd24-4c28-8434-48bc942457d9]  WARN 1 --- [messageListenerContainer-2] s.a.r.l.ConditionalRejectingErrorHandler : Execution of Rabbit message listener failed.

org.springframework.amqp.rabbit.listener.exception.ListenerExecutionFailedException: Listener threw exception
        at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.wrapToListenerExecutionFailedExceptionIfNeeded(AbstractMessageListenerContainer.java:870)
        at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:780)
        at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:700)
        at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$001(SimpleMessageListenerContainer.java:95)
        at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$1.invokeListener(SimpleMessageListenerContainer.java:187)
        at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.invokeListener(SimpleMessageListenerContainer.java:1187)
        at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:681)
        at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.doReceiveAndExecute(SimpleMessageListenerContainer.java:1165)
        at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.receiveAndExecute(SimpleMessageListenerContainer.java:1149)
        at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$1100(SimpleMessageListenerContainer.java:95)
        at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.run(SimpleMessageListenerContainer.java:1312)
        at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.messaging.MessageHandlingException: nested exception is java.lang.NullPointerException
        at org.springframework.integration.handler.MethodInvokingMessageProcessor.processMessage(MethodInvokingMessageProcessor.java:96)
        at org.springframework.integration.handler.ServiceActivatingHandler.handleRequestMessage(ServiceActivatingHandler.java:89)
        at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:109)
        at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:127)
        at org.springframework.integration.dispatcher.AbstractDispatcher.tryOptimizedDispatch(AbstractDispatcher.java:116)
        at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:148)
        at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:121)
        at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:77)
        at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:423)
        at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:373)
        at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:115)
        at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:45)
        at org.springframework.messaging.core.AbstractMessageSendingTemplate.send(AbstractMessageSendingTemplate.java:105)
        at org.springframework.integration.handler.AbstractMessageProducingHandler.sendOutput(AbstractMessageProducingHandler.java:292)
        at org.springframework.integration.handler.AbstractMessageProducingHandler.produceOutput(AbstractMessageProducingHandler.java:212)
        at org.springframework.integration.handler.AbstractMessageProducingHandler.sendOutputs(AbstractMessageProducingHandler.java:129)
        at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:115)
        at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:127)
        at org.springframework.integration.dispatcher.AbstractDispatcher.tryOptimizedDispatch(AbstractDispatcher.java:116)
        at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:148)
        at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:121)
        at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:77)
        at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:423)
        at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:373)
        at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:115)
        at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:45)
        at org.springframework.messaging.core.AbstractMessageSendingTemplate.send(AbstractMessageSendingTemplate.java:105)
        at org.springframework.integration.endpoint.MessageProducerSupport.sendMessage(MessageProducerSupport.java:171)
        at org.springframework.integration.amqp.inbound.AmqpInboundChannelAdapter.access$400(AmqpInboundChannelAdapter.java:45)
        at org.springframework.integration.amqp.inbound.AmqpInboundChannelAdapter$1.onMessage(AmqpInboundChannelAdapter.java:95)
        at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:777)
        ... 10 common frames omitted
Caused by: java.lang.NullPointerException: null

Answer 1

经过长时间的调查，发现Spring或rabbitMQ没有任何问题。根本原因在于我自己的代码。

问题附带的日志具有完整的堆栈跟踪，但 java 截断了堆栈跟踪!

Java 1.5.0 引入了标志 OmitStackTraceInFastThrow，默认启用。这就是性能优化。它从异常中删除堆栈跟踪的公共(public)部分。

就我而言，我有此异常前 130 次出现的完整堆栈跟踪。进一步发生的事件已被截断。获取完整堆栈跟踪的最简单方法是重新启动应用程序。

参见http://jawspeak.com/2010/05/26/hotspot-caused-exceptions-to-lose-their-stack-traces-in-production-and-the-fix/了解详情。