在spring集成中定制变压器

Question

<int:transformer id="errorHandler"
    input-channel="errorChannel"
    ref="myTransformer" method="transform" />
<bean id="myTransformer" class="com.sample.MyTransformer" />

public class MyTransformer {
    private static Logger logger = Logger.getLogger(MyTransformer.class);

    public String transform(org.springframework.integration.handler.ReplyRequiredException e) {
        logger.error("timeout exception is thrown");
        return "Error in processing request.";
    }
}

上面的代码可以工作，客户端得到“处理请求中的错误”，服务器日志中有一个条目“Timeout exception is through”。但我在日志中也看到以下异常：

2016-06-30 16:25:27,827 ERROR [org.springframework.integration.handler.LoggingHandler] org.springframework.integration.handler.ReplyRequiredException: No reply produced by handler 'org.springframework.integration.config.ServiceActivatorFactoryBean#0', and its 'requiresReply' property is set to true.
    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:147)
    at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:120)
    at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:77)
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:442)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:115)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSendAndReceive(GenericMessagingTemplate.java:150)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSendAndReceive(GenericMessagingTemplate.java:45)
    at org.springframework.messaging.core.AbstractMessagingTemplate.sendAndReceive(AbstractMessagingTemplate.java:42)
    at org.springframework.integration.core.MessagingTemplate.sendAndReceive(MessagingTemplate.java:97)
    at org.springframework.integration.gateway.MessagingGatewaySupport.doSendAndReceive(MessagingGatewaySupport.java:422)
    at org.springframework.integration.gateway.MessagingGatewaySupport.sendAndReceiveMessage(MessagingGatewaySupport.java:390)
    at org.springframework.integration.ip.tcp.TcpInboundGateway.doOnMessage(TcpInboundGateway.java:119)
    at org.springframework.integration.ip.tcp.TcpInboundGateway.onMessage(TcpInboundGateway.java:97)
    at org.springframework.integration.ip.tcp.connection.TcpNetConnection.run(TcpNetConnection.java:182)
    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)

MyTransformer的实现似乎不正确。

你能帮我定制变压器吗？如何在转换方法中获得有效负载，这样我就可以回复客户机作为‘处理请求的错误。有效载荷='+有效载荷？

<int-ip:tcp-inbound-gateway id="gatewayCrLf"
    connection-factory="crLfServer"
    request-channel="requestChannel"
    error-channel="tcpErrorChannel"
    reply-timeout="10000"
    />
<int:channel id="tcpErrorChannel" /> 

<int:service-activator input-channel="requestChannel" ref="gateway" requires-reply="true"/>
<int:gateway id="gateway" default-request-channel="timeoutChannel" default-reply-timeout="10000" />
<int:object-to-string-transformer id="serverBytes2String"
    input-channel="timeoutChannel"
    output-channel="serviceChannel"/>

<int:channel id="timeoutChannel">
    <int:dispatcher task-executor="timeoutExecutor"/>
</int:channel>

<bean id="timeoutExecutor" class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
    <property name="corePoolSize" value="5" />
    <property name="maxPoolSize" value="100" />
    <property name="queueCapacity" value="50" />
</bean>

2016-07-05 12:17:34,266 ERROR [org.springframework.integration.ip.tcp.connection.TcpNetConnection] Exception sending message: GenericMessage [payload=byte[67], headers={timestamp=1467735444239, id=30eb099e-955d-1bd3-1789-49aa9fc84b6f, ip_tcp_remotePort=64055, ip_address=127.0.0.1, ip_localInetAddress=/127.0.0.1, ip_hostname=127.0.0.1, ip_connectionId=127.0.0.1:64055:5678:908d39a1-d027-4753-b144-59b9c0390fd7}]
org.springframework.messaging.MessagingException: failure occurred in error-handling flow; nested exception is org.springframework.messaging.MessageDeliveryException: Dispatcher has no subscribers for channel 'org[e-mail]'.; nested exception is org.springframework.integration.MessageDispatchingException: Dispatcher has no subscribers
    at org.springframework.integration.gateway.MessagingGatewaySupport.doSendAndReceive(MessagingGatewaySupport.java:452)
    at org.springframework.integration.gateway.MessagingGatewaySupport.sendAndReceiveMessage(MessagingGatewaySupport.java:390)
    at org.springframework.integration.ip.tcp.TcpInboundGateway.doOnMessage(TcpInboundGateway.java:119)
    at org.springframework.integration.ip.tcp.TcpInboundGateway.onMessage(TcpInboundGateway.java:97)
    at org.springframework.integration.ip.tcp.connection.TcpNetConnection.run(TcpNetConnection.java:182)
    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.springframework.messaging.MessageDeliveryException: Dispatcher has no subscribers for channel 'org[e-mail]'.; nested exception is org.springframework.integration.MessageDispatchingException: Dispatcher has no subscribers
    at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:81)
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:442)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:115)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSendAndReceive(GenericMessagingTemplate.java:150)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSendAndReceive(GenericMessagingTemplate.java:45)
    at org.springframework.messaging.core.AbstractMessagingTemplate.sendAndReceive(AbstractMessagingTemplate.java:42)
    at org.springframework.integration.core.MessagingTemplate.sendAndReceive(MessagingTemplate.java:97)
    at org.springframework.integration.gateway.MessagingGatewaySupport.doSendAndReceive(MessagingGatewaySupport.java:449)
    ... 7 more
Caused by: org.springframework.integration.MessageDispatchingException: Dispatcher has no subscribers
    at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:153)
    at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:120)
    at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:77)
    ... 14 more

非常感谢Artem的完美解决方案。

Answer 1

看起来这是您的另一个问题的继续，在spring Integration中的tcp-inbound-gateway中的回复-超时含义。

那么，ReplyRequiredException是 的结果。

requires-reply=“true”-请阅读它的描述。不过，您可以使用它，并将其设置为false（默认设置），但是您的“超时”逻辑将不起作用。所以，你别无选择，除非继续忍受：

ERROR [org.springframework.integration.handler.LoggingHandler] org.springframework.integration.handler.ReplyRequiredException

不过，这只是默认errorchannel订阅方之一的影响:http://docs.spring.io/spring-integration/reference/html/configuration.html#namespace-errorhandler。

关于你的最后一个问题。所有异常都包装到ErrorMessage中，并发送到ErrorChannel中。通常，异常被包装到MessagingException中，例如，在本例中如下所示：

else if (this.requiresReply && !isAsync()) {
    throw new ReplyRequiredException(message, "No reply produced by handler '" +
            getComponentName() + "', and its 'requiresReply' property is set to true.");
}

请注意messagector参数，它正是一个requestmessage，在我们的场景中没有应答。您可以从中提取所需的有效负载。

更新

由于此ReplyRequiredException是已知异常，因此不需要将其视为错误。

嗯，即使它是一个已知的异常，但它在其他组件和场景中是一个重要的异常，当它可能不合适时，不会收到回复。ReplyRequiredException在框架组件中非常常见，因此将其转移到不同的类别对应用程序来说可能是一个很大的体系结构错误。