异步流中出站网关的错误处理

Question

我有一个这样的集成流程：

@Bean
public IntegrationFlow inboundRequestFlow()
{
    return IntegrationFlows.from( inboundRequestGateway() )
        .log( ... )
        .filter(  requestValidator,
            spec -> spec.discardChannel( invalidRequestChannel() ) )
        .bridge( spec -> spec.requiresReply( false ) )
        .channel( asyncFlowChannel )
        .wireTap(
            //sends a NO_CONTENT reply if the request is ok
            flow -> flow.enrichHeaders( spec -> spec.header( HttpHeaders.STATUS_CODE, HttpStatus.NO_CONTENT ).defaultOverwrite( true ) )
                .transform( payload -> "" )
                .channel( inboundGatewayReplyChannel() )
        ).get();

}

@Bean
public IntegrationFlow outboundFlow()
{
    return IntegrationFlows.from( asyncFlowChannel)
        .log( ... )
        .transform( ... )
        .transform( ... )
        .split(... )            
        .resequence( ... )
        .enrichHeaders( ... )
        .log( ... )
        .transform( ... )
        .handle( this.outboundSOAPGateway() )
        .log( .. )
        .handle( ... )
        .bridge( spec -> spec.requiresReply( false ) )
        .channel( anotherAsyncFlowChannel )
        .get();
}

Answer 1

任何MessageHandlerendpoint都可以使用AbstractrequestHandlerAdvise提供。其中之一是ExpressionEvaluatingRequestHandlerAdvise，在这里可以捕获异常并将其发送到FailureChannel:https://docs.spring.io/spring-integration/docs/5.0.0.release/reference/html/messaging-endpoints-chapter.html#expression-advision。

为此，.handle(this.outboundsoapgateway())可以提供第二个参数，例如：

.handle((GenericHandler<?>) (p, h) -> {
                    throw new RuntimeException("intentional");
                }, e -> e.advice(retryAdvice()))

在本例中，我使用

@Bean
public RequestHandlerRetryAdvice retryAdvice() {
    RequestHandlerRetryAdvice requestHandlerRetryAdvice = new RequestHandlerRetryAdvice();
    requestHandlerRetryAdvice.setRecoveryCallback(new ErrorMessageSendingRecoverer(recoveryChannel()));
    return requestHandlerRetryAdvice;
}

但对于ExpressionEvaluatingRequestHandlerAdvision也是如此。

顺便说一句，retryAdvise()也可以为您提供这个技巧。请参见其ErrorMessageSendingRecoverer。