java - 无法转换 [com.sun.proxy.$Proxy32 ScopedObject 类型的值

Question

我正在使用 spring batch，下面是配置。

<beans:bean id="symfonyJob" class="com.st.symfony.Symfony"
    p:dir="${symfony.dir}" p:consolePath="${symfony.console.path}"
    p:strUtil-ref="strUtil" p:logFilePath="${batch.log.file.path}.#{jobParameters[batch_id]}" scope="step"/>


<beans:bean id="importExchangesItemWriter"
    class="com.st.batch.foundation.ImportExchangesItemWriter"
    p:symfony-ref="symfonyJob" p:replyTimeout="${import.exchanges.reply.timeout}" scope="step"/>

<beans:bean id="importExchangesFileItemReader"
    class="org.springframework.batch.item.file.MultiThreadedFlatFileItemReader"
    p:resource="file:${spring.tmp.batch.dir}/#{jobParameters[batch_id]}/exchanges.txt"
    p:lineMapper-ref="stLineMapper" p:startAt="#{stepExecutionContext['startAt']}"
    p:maxItemCount="#{stepExecutionContext['itemsCount']}" scope="step" />

<step id="importExchangesStep">
    <tasklet transaction-manager="transactionManager">
        <chunk reader="importExchangesFileItemReader" writer="importExchangesItemWriter"
            commit-interval="${import.exchanges.commit.interval}" />
    </tasklet>
</step>

<job id="importExchangesJob" restartable="true">

    <step id="importExchangesStep.master">
        <partition partitioner="importExchangesPartitioner"
            handler="importExchangesPartitionHandler" />
    </step>

</job>

在我将 symfonyJob 和 importExchangeItemWriter 的范围更改为 scope="step"之前，一切正常。一旦我改变了范围，我就得到了

ERROR: org.springframework.batch.core.step.AbstractStep - Encountered an error executing step importExchangesStep in job importExchangesJob
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.importExchangesItemWriter' defined in file [/home/vishal/install/sts-bundle/vfabric-tc-server-developer-2.9.6.RELEASE/base-instance/wtpwebapps/spring/WEB-INF/classes/META-INF/spring/batch/jobs/foundation/steps/import-exchanges.xml]: Initialization of bean failed; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'com.sun.proxy.$Proxy32 implementing org.springframework.aop.scope.ScopedObject,java.io.Serializable,org.springframework.aop.framework.AopInfrastructureBean,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised' to required type 'com.st.symfony.Symfony' for property 'symfony'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [com.sun.proxy.$Proxy32 implementing org.springframework.aop.scope.ScopedObject,java.io.Serializable,org.springframework.aop.framework.AopInfrastructureBean,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised] to required type [com.st.symfony.Symfony] for property 'symfony': no matching editors or conversion strategy found
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:532)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:461)
    at org.springframework.beans.factory.support.AbstractBeanFactory$2.getObject(AbstractBeanFactory.java:333)
    at org.springframework.batch.core.scope.StepScope.get(StepScope.java:110)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:329)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.aop.target.SimpleBeanTargetSource.getTarget(SimpleBeanTargetSource.java:34)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:184)
    at com.sun.proxy.$Proxy26.write(Unknown Source)
    at org.springframework.batch.core.step.item.SimpleChunkProcessor.writeItems(SimpleChunkProcessor.java:175)
    at org.springframework.batch.core.step.item.SimpleChunkProcessor.doWrite(SimpleChunkProcessor.java:151)
    at org.springframework.batch.core.step.item.SimpleChunkProcessor.write(SimpleChunkProcessor.java:274)
    at org.springframework.batch.core.step.item.SimpleChunkProcessor.process(SimpleChunkProcessor.java:199)
    at org.springframework.batch.core.step.item.ChunkOrientedTasklet.execute(ChunkOrientedTasklet.java:75)
    at org.springframework.batch.core.step.tasklet.TaskletStep$ChunkTransactionCallback.doInTransaction(TaskletStep.java:402)
    at org.springframework.batch.core.step.tasklet.TaskletStep$ChunkTransactionCallback.doInTransaction(TaskletStep.java:326)
    at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:131)
    at org.springframework.batch.core.step.tasklet.TaskletStep$2.doInChunkContext(TaskletStep.java:267)
    at org.springframework.batch.core.scope.context.StepContextRepeatCallback.doInIteration(StepContextRepeatCallback.java:77)
    at org.springframework.batch.repeat.support.RepeatTemplate.getNextResult(RepeatTemplate.java:368)
    at org.springframework.batch.repeat.support.RepeatTemplate.executeInternal(RepeatTemplate.java:215)
    at org.springframework.batch.repeat.support.RepeatTemplate.iterate(RepeatTemplate.java:144)
    at org.springframework.batch.core.step.tasklet.TaskletStep.doExecute(TaskletStep.java:253)
    at org.springframework.batch.core.step.AbstractStep.execute(AbstractStep.java:198)
    at org.springframework.batch.integration.partition.StepExecutionRequestHandler.handle(StepExecutionRequestHandler.java:64)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.expression.spel.support.ReflectiveMethodExecutor.execute(ReflectiveMethodExecutor.java:69)
    at org.springframework.expression.spel.ast.MethodReference$MethodValueRef.getValue(MethodReference.java:97)
    at org.springframework.expression.spel.ast.CompoundExpression.getValueInternal(CompoundExpression.java:81)
    at org.springframework.expression.spel.ast.SpelNodeImpl.getTypedValue(SpelNodeImpl.java:102)
    at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:103)
    at org.springframework.integration.util.AbstractExpressionEvaluator.evaluateExpression(AbstractExpressionEvaluator.java:126)
    at org.springframework.integration.util.MessagingMethodInvokerHelper.processInternal(MessagingMethodInvokerHelper.java:227)
    at org.springframework.integration.util.MessagingMethodInvokerHelper.process(MessagingMethodInvokerHelper.java:127)
    at org.springframework.integration.handler.MethodInvokingMessageProcessor.processMessage(MethodInvokingMessageProcessor.java:73)
    at org.springframework.integration.handler.ServiceActivatingHandler.handleRequestMessage(ServiceActivatingHandler.java:67)
    at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:134)
    at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:73)
    at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:115)
    at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:102)
    at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:77)
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:157)
    at org.springframework.integration.core.MessagingTemplate.doSend(MessagingTemplate.java:288)
    at org.springframework.integration.core.MessagingTemplate.doSendAndReceive(MessagingTemplate.java:318)
    at org.springframework.integration.core.MessagingTemplate.sendAndReceive(MessagingTemplate.java:239)
    at org.springframework.integration.gateway.MessagingGatewaySupport.doSendAndReceive(MessagingGatewaySupport.java:233)
    at org.springframework.integration.gateway.MessagingGatewaySupport.sendAndReceiveMessage(MessagingGatewaySupport.java:207)
    at org.springframework.integration.amqp.inbound.AmqpInboundGateway.access$200(AmqpInboundGateway.java:47)
    at org.springframework.integration.amqp.inbound.AmqpInboundGateway$1.onMessage(AmqpInboundGateway.java:87)
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:693)
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:586)
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$001(SimpleMessageListenerContainer.java:75)
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$1.invokeListener(SimpleMessageListenerContainer.java:154)
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.invokeListener(SimpleMessageListenerContainer.java:1113)
    at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:559)
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.doReceiveAndExecute(SimpleMessageListenerContainer.java:904)
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.receiveAndExecute(SimpleMessageListenerContainer.java:888)
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$500(SimpleMessageListenerContainer.java:75)
    at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.run(SimpleMessageListenerContainer.java:989)
    at java.lang.Thread.run(Thread.java:724)
Caused by: org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'com.sun.proxy.$Proxy32 implementing org.springframework.aop.scope.ScopedObject,java.io.Serializable,org.springframework.aop.framework.AopInfrastructureBean,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised' to required type 'com.st.symfony.Symfony' for property 'symfony'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [com.sun.proxy.$Proxy32 implementing org.springframework.aop.scope.ScopedObject,java.io.Serializable,org.springframework.aop.framework.AopInfrastructureBean,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised] to required type [com.st.symfony.Symfony] for property 'symfony': no matching editors or conversion strategy found
    at org.springframework.beans.BeanWrapperImpl.convertIfNecessary(BeanWrapperImpl.java:463)
    at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:494)
    at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:488)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.convertForProperty(AbstractAutowireCapableBeanFactory.java:1437)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1396)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1132)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:522)
    ... 62 more
Caused by: java.lang.IllegalStateException: Cannot convert value of type [com.sun.proxy.$Proxy32 implementing org.springframework.aop.scope.ScopedObject,java.io.Serializable,org.springframework.aop.framework.AopInfrastructureBean,org.springframework.aop.SpringProxy,org.springframework.aop.framework.Advised] to required type [com.st.symfony.Symfony] for property 'symfony': no matching editors or conversion strategy found
    at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:264)
    at org.springframework.beans.BeanWrapperImpl.convertIfNecessary(BeanWrapperImpl.java:448)
    ... 68 more

即使 reader 有范围步骤，它也能正常工作，但一旦我将它添加到 writer，我就开始收到此错误。

Answer 1

我在稍微不同的情况下看到了这个错误:

我没有遵循 HibernateDAO bean 的正确模式，它需要方法接口(interface)并将接口(interface)类型作为属性而不是 DAO 实现类传递给服务层 spring bean。

applicationContext.xml

<bean id="myEntityDAO" class="com.me.etc.MyEntityDAOImpl" parent="hibernateDAO"/>

<bean id="myEntityService class="com.me.etc.MyEntityServiceImpl">
  <property name="myEntityDAO" ref="myEntityDAO" />
</bean>

MyEntityServiceImpl.java

class MyEntityServiceImpl extends MyEntityService {
  .
  .
  .
  // I got the error when I had this property of class MyEntityDAOImpl
  private MyEntityDAOInterface myEntityDAO;

  // changed the setter as well to match
  @Required
  public setMyEntityDAO(MyEntityDAOInterface myEntityDAO) {
     this.myEntityDAO = myEntityDAO;
  }
  .
  .
  .
}

Spring 希望传入接口(interface)，而不是导致“无法转换类型值”错误的已实现类文件。