使用<int-jpa：outbound-channel-adapter保留實體列表

Question

我可能在這里遺漏了一些東西，但我似乎找不到任何關於使用Spring Integration JPA出站通道適配器持久保存實體列表的文檔。 我有一個非常簡單的場景，應該輪詢數據庫並將新數據復制到另一個數據庫。 從而：

<int-jpa:inbound-channel-adapter channel="myChannel"
    entity-class="my.package.MyClass"
    entity-manager="mysqlEntityManager"
    auto-startup="true">
    <int:poller fixed-rate="5000">
        <int:transactional propagation="REQUIRED" transaction-manager="mysqlTransactionManager"/>
    </int:poller>
</int-jpa:inbound-channel-adapter>

<int:channel id="myChannel" />

<int-jpa:outbound-channel-adapter channel="myChannel" 
    entity-class="my.package.MyClass"
    entity-manager="hsqldbEntityManager">
    <int-jpa:transactional transaction-manager="hsqldbTransactionManager" />                                    
</int-jpa:outbound-channel-adapter>

inbound-channel-adapter返回List<MyClass> ，然后outbound-channel-adapter拋出下面的堆棧跟蹤...

如何配置適配器以接受entites列表？ 我不想在入站適配器/輪詢器中設置每個輪詢的最大消息數，因為我更喜歡最小的數據庫操作。

任何幫助贊賞。

Spring docs： http ： //static.springsource.org/spring-integration/docs/3.0.0.M1/reference/html/jpa.html

[task-scheduler-1] ERROR org.springframework.integration.handler.LoggingHandler - org.springframework.integration.MessageHandlingException: error occurred in message handler [org.springframework.integration.jpa.outbound.JpaOutboundGateway@165d2be]
    at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:79)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:319)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
    at $Proxy24.handleMessage(Unknown Source)
    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.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:128)
    at org.springframework.integration.core.MessagingTemplate.doSend(MessagingTemplate.java:288)
    at org.springframework.integration.core.MessagingTemplate.send(MessagingTemplate.java:149)
    at org.springframework.integration.endpoint.SourcePollingChannelAdapter.handleMessage(SourcePollingChannelAdapter.java:97)
    at org.springframework.integration.endpoint.AbstractTransactionSynchronizingPollingEndpoint.doPoll(AbstractTransactionSynchronizingPollingEndpoint.java:82)
    at org.springframework.integration.endpoint.AbstractPollingEndpoint$1.call(AbstractPollingEndpoint.java:146)
    at org.springframework.integration.endpoint.AbstractPollingEndpoint$1.call(AbstractPollingEndpoint.java:144)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:319)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
    at $Proxy23.call(Unknown Source)
    at org.springframework.integration.endpoint.AbstractPollingEndpoint$Poller$1.run(AbstractPollingEndpoint.java:236)
    at org.springframework.integration.util.ErrorHandlingTaskExecutor$1.run(ErrorHandlingTaskExecutor.java:52)
    at org.springframework.core.task.SyncTaskExecutor.execute(SyncTaskExecutor.java:48)
    at org.springframework.integration.util.ErrorHandlingTaskExecutor.execute(ErrorHandlingTaskExecutor.java:49)
    at org.springframework.integration.endpoint.AbstractPollingEndpoint$Poller.run(AbstractPollingEndpoint.java:231)
    at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:53)
    at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:81)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(Unknown Source)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.IllegalArgumentException: Unknown entity: java.util.ArrayList
    at org.hibernate.ejb.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:692)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:240)
    at $Proxy18.merge(Unknown Source)
    at org.springframework.integration.jpa.core.DefaultJpaOperations.merge(DefaultJpaOperations.java:175)
    at org.springframework.integration.jpa.core.JpaExecutor.executeOutboundJpaOperation(JpaExecutor.java:223)
    at org.springframework.integration.jpa.outbound.JpaOutboundGateway.handleRequestMessage(JpaOutboundGateway.java:81)
    at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:134)
    at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:73)
    ... 48 more
Caused by: org.hibernate.MappingException: Unknown entity: java.util.ArrayList
    at org.hibernate.impl.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:693)
    at org.hibernate.impl.SessionImpl.getEntityPersister(SessionImpl.java:1485)
    at org.hibernate.event.def.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:232)
    at org.hibernate.event.def.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:84)
    at org.hibernate.impl.SessionImpl.fireMerge(SessionImpl.java:867)
    at org.hibernate.impl.SessionImpl.merge(SessionImpl.java:851)
    at org.hibernate.impl.SessionImpl.merge(SessionImpl.java:855)
    at org.hibernate.ejb.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:686)
    ... 59 more

Answer 1

我創建了一個Jira以實現這一改進：

https://jira.springsource.org/browse/INT-3029

作為解決方法，您還可以擴展DefaultJpaOperations （org.springframework.integration.jpa.core）並自定義persist（）方法，允許您處理Collection類型參數。 有關詳情，請參閱：

使用JPA / EJB3批量插入

適配器具有XML命名空間屬性jpa-operations ，允許您提供對自定義實現的引用。 有關詳細信息，請參閱http://static.springsource.org/spring-integration/docs/latest-ga/reference/html/jpa.html#jpa-namespace-support-common-attributes

Answer 2

出站JPA適配器當前不支持持久化實體列表; 隨時打開一個新的JIRA問題 。 您可以在出站適配器之前添加一個簡單的<splitter/> （沒有屬性，只有輸入和輸出通道），它會將列表分成單個權限。

但是，使用當前配置，每個持久性將在單獨的事務中完成。

無論如何，您可能希望同步兩個事務，因此您應該在mysql事務的同時啟動hsql事務，以便Spring盡最大努力同步兩個事務（盡可能將它們盡可能地一起提交）。

要做到這一點，你需要像Dave Syer關於這個主題的優秀文章的“盡力而為1PC”部分中的ChainedTransactionManager這樣的東西。

這樣，每個拆分實體將在同一事務中提交。