Java Spring批处理中的JMS读取器导致NoClassDefFoundError

我们将Spring Batch 2.1.9与Spring 3.1.1一起使用，并设置了一个

作业

，该作业执行以下操作：

• JMS

  ItemReader

  （使用ActiveMQ 5.6.0）读取传入消息，并传递给：
• 发送成批电子邮件的

  ItemWriter

这都是作为一个WAR部署的，在WebLogic10.3.x下运行。现在，我们已经让这种设计在其他地方正常工作，但是在这个特定的部署中，如果在大量不活动之后向

ItemReader

发送新消息，则会发生以下情况：

09:20:28,155 - DEBUG (org.springframework.batch.repeat.support.RepeatTemplate) - Repeat operation about to start at count=2
10:39:38,733 - WARN  (org.springframework.jms.connection.CachingConnectionFactory) - Encountered a JMSException - resetting the underlying JMS Connection
javax.jms.JMSException: Unexpected error occured: java.lang.NoClassDefFoundError: org/apache/activemq/command/ActiveMQObjectMessage
    at org.apache.activemq.util.JMSExceptionSupport.create(JMSExceptionSupport.java:49)
    at org.apache.activemq.ActiveMQConnection.onAsyncException(ActiveMQConnection.java:1934)
    at org.apache.activemq.ActiveMQConnection.onException(ActiveMQConnection.java:1951)
    at org.apache.activemq.transport.TransportFilter.onException(TransportFilter.java:101)
    at org.apache.activemq.transport.ResponseCorrelator.onException(ResponseCorrelator.java:126)
    at org.apache.activemq.transport.TransportFilter.onException(TransportFilter.java:101)
    at org.apache.activemq.transport.TransportFilter.onException(TransportFilter.java:101)
    at org.apache.activemq.transport.WireFormatNegotiator.onException(WireFormatNegotiator.java:160)
    at org.apache.activemq.transport.AbstractInactivityMonitor.onException(AbstractInactivityMonitor.java:268)
    at org.apache.activemq.transport.TransportSupport.onException(TransportSupport.java:96)
    at org.apache.activemq.transport.tcp.TcpTransport.run(TcpTransport.java:213)
    at java.lang.Thread.run(Thread.java:662)
Caused by: java.io.IOException: Unexpected error occured: java.lang.NoClassDefFoundError: org/apache/activemq/command/ActiveMQObjectMessage
    at org.apache.activemq.transport.tcp.TcpTransport.run(TcpTransport.java:211)
    ... 1 more
Caused by: java.lang.NoClassDefFoundError: org/apache/activemq/command/ActiveMQObjectMessage
    at org.apache.activemq.openwire.v9.ActiveMQObjectMessageMarshaller.createObject(ActiveMQObjectMessageMarshaller.java:55)
    at org.apache.activemq.openwire.OpenWireFormat.tightUnmarshalNestedObject(OpenWireFormat.java:446)
    at org.apache.activemq.openwire.v9.BaseDataStreamMarshaller.tightUnmarsalNestedObject(BaseDataStreamMarshaller.java:125)
    at org.apache.activemq.openwire.v9.MessageDispatchMarshaller.tightUnmarshal(MessageDispatchMarshaller.java:71)
    at org.apache.activemq.openwire.OpenWireFormat.doUnmarshal(OpenWireFormat.java:371)
    at org.apache.activemq.openwire.OpenWireFormat.unmarshal(OpenWireFormat.java:285)
    at org.apache.activemq.transport.tcp.TcpTransport.readCommand(TcpTransport.java:229)
    at org.apache.activemq.transport.tcp.TcpTransport.doRun(TcpTransport.java:221)
    at org.apache.activemq.transport.tcp.TcpTransport.run(TcpTransport.java:204)
    ... 1 more
Caused by: java.lang.ClassNotFoundException: org.apache.activemq.command.ActiveMQObjectMessage
    at weblogic.utils.classloaders.GenericClassLoader.findLocalClass(GenericClassLoader.java:297)
    at weblogic.utils.classloaders.GenericClassLoader.findClass(GenericClassLoader.java:270)
    at weblogic.utils.classloaders.ChangeAwareClassLoader.findClass(ChangeAwareClassLoader.java:64)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
    at weblogic.utils.classloaders.GenericClassLoader.loadClass(GenericClassLoader.java:179)
    at weblogic.utils.classloaders.ChangeAwareClassLoader.loadClass(ChangeAwareClassLoader.java:43)
    ... 10 more

之后似乎会关闭一个会话（我们使用Spring的

CachingConnectionFactory

，FWIW）

在大约20次以上的

NoClassDefFoundError

跟踪后，读取操作完成：

10:39:41,624 - DEBUG (org.springframework.batch.repeat.support.RepeatTemplate) - Repeat is complete according to policy and result value.
10:39:41,624 - DEBUG (org.springframework.batch.core.step.item.ChunkOrientedTasklet) - Inputs not busy, ended: false
10:39:41,624 - DEBUG (org.springframework.batch.core.step.tasklet.TaskletStep) - Applying contribution: [StepContribution: read=0, written=0, filtered=0, readSkips=100, writeSkips=0, processSkips=0, exitStatus=EXECUTING]
10:39:41,639 - DEBUG (org.springframework.batch.core.step.tasklet.TaskletStep) - Saving step execution before commit: StepExecution: id=1, version=5, name=fetchEmailsStep, status=STARTED, exitStatus=EXECUTING, readCount=0, filterCount=0, writeCount=0 readSkipCount=500, writeSkipCount=0, processSkipCount=0, commitCount=5, rollbackCount=0, exitDescription=
10:39:41,639 - DEBUG (org.springframework.batch.repeat.support.RepeatTemplate) - Repeat operation about to start at count=6
10:39:41,639 - DEBUG (org.springframework.batch.core.scope.context.StepContextRepeatCallback) - Preparing chunk execution for StepContext: org.springframework.batch.core.scope.context.StepContext@306897b6
10:39:41,639 - DEBUG (org.springframework.batch.core.scope.context.StepContextRepeatCallback) - Chunk execution starting: queue size=0
10:39:41,639 - DEBUG (org.springframework.batch.repeat.support.RepeatTemplate) - Starting repeat context.
10:39:41,639 - DEBUG (org.springframework.batch.repeat.support.RepeatTemplate) - Repeat operation about to start at count=1

但最终结果是，我们的消息不会传递给

ItemWriter

有人能解释一下为什么我们会突然出现

NoClassDefFoundError

错误吗

我真的希望避免仅仅为了解决Weblogic类加载器问题而开始改变部署方式，例如必须将ActiveMQ JAR移动到\server\lib等

---

我们的Spring配置：

<bean id="jmsEmailFetcher" class="our.code.batch.AquilaJmsItemReader">
    <property name="jmsTemplate" ref="batchEmailJmsTemplate" />
</bean>

<bean id="batchEmailJmsTemplate" class="org.springframework.jms.core.JmsTemplate">
    <property name="connectionFactory" ref="springBatchJmsCachingConnF"/>
    <property name="defaultDestination" ref="springBatchIncomingEmailQueue" />
    <!-- Do *not* need to set a timeout: <property name="receiveTimeout" value="1800000" /> -->
</bean>

<bean id="springBatchJmsCachingConnF" class="org.springframework.jms.connection.CachingConnectionFactory">
    <property name="targetConnectionFactory" ref="srcConnectionFactory"/>
    <property name="reconnectOnException" value="true"/>
    <!-- Leave "sessionCacheSize" as default (1) until we have a better answer -->
</bean>

<jee:jndi-lookup id="srcConnectionFactory" jndi-name="${jndi.jms.connfactory}">
    <jee:environment>
        java.naming.factory.initial = <snip>
        java.naming.provider.url = <snip>
    </jee:environment>
</jee:jndi-lookup>

java.naming.factory.initial=
java.naming.provider.url=

如果有人对此感兴趣，几乎可以肯定，其原因如下：

• 定期在Weblogic上重新部署应用程序，导致：
• 类意外卸载
• 长时间运行的轮询进程检测丢失的类，并抛出异常
• 其他监听任务结束的进程启动，它们自身无法正常工作

---

应该只在WEB-INF/lib文件夹中包含库，我想您已经在这样做了。阅读这篇文章，看看它是否对你有帮助

<bean id="jmsEmailFetcher" class="our.code.batch.AquilaJmsItemReader">
    <property name="jmsTemplate" ref="batchEmailJmsTemplate" />
</bean>

<bean id="batchEmailJmsTemplate" class="org.springframework.jms.core.JmsTemplate">
    <property name="connectionFactory" ref="springBatchJmsCachingConnF"/>
    <property name="defaultDestination" ref="springBatchIncomingEmailQueue" />
    <!-- Do *not* need to set a timeout: <property name="receiveTimeout" value="1800000" /> -->
</bean>

<bean id="springBatchJmsCachingConnF" class="org.springframework.jms.connection.CachingConnectionFactory">
    <property name="targetConnectionFactory" ref="srcConnectionFactory"/>
    <property name="reconnectOnException" value="true"/>
    <!-- Leave "sessionCacheSize" as default (1) until we have a better answer -->
</bean>

<jee:jndi-lookup id="srcConnectionFactory" jndi-name="${jndi.jms.connfactory}">
    <jee:environment>
        java.naming.factory.initial = <snip>
        java.naming.provider.url = <snip>
    </jee:environment>
</jee:jndi-lookup>