Spring Integration:没有可用的输出通道或回复通道标头

Question

我写了一个简单的spring集成应用程序,它将文件从一个目录移动到另一个目录,它看起来像这样:

@Bean
@InboundChannelAdapter(value="requestChannel", poller = @Poller(fixedDelay="100"))
public FileReadingMessageSource adapter(){
    FileReadingMessageSource source = new FileReadingMessageSource();
    source.setDirectory(new File("D:/TestIn"));
    return source;

}

@Bean 
MessageChannel requestChannel(){
    return new DirectChannel();
}

@Bean
@ServiceActivator(inputChannel="requestChannel")
public FileWritingMessageHandler handle(){
    FileWritingMessageHandler handler = new FileWritingMessageHandler(new File("D:/TestOut"));
    handler.setDeleteSourceFiles(true);
    return handler;
}

它工作得非常好,但每次复制操作都会给我这个例外

    2015-03-26 09:56:39.222  INFO 4772 --- [ask-scheduler-5] o.s.i.file.FileReadingMessageSource      : Created message: [GenericMessage [payload=D:\TestIn\9.txt, headers={id=d8b27257-0a90-b7ad-65cb-85e93668fb5a, timestamp=1427360199222}]]
2015-03-26 09:56:39.223 ERROR 4772 --- [ask-scheduler-5] o.s.integration.handler.LoggingHandler   : org.springframework.messaging.MessagingException: ; nested exception is org.springframework.messaging.core.DestinationResolutionException: no output-channel or replyChannel header available
    at org.springframework.integration.dispatcher.AbstractDispatcher.wrapExceptionIfNecessary(AbstractDispatcher.java:133)

我在另一个主题中读到,当您在代码中的某处过滤掉标题时会发生这种情况,但此跟踪的第一行告诉我,生成的唯一标头是id和timestamp.

Answer 1

一切看起来都不错,但没有:你没有面对这个filter out the headers somewhere问题.

这只是因为FileWritingMessageHandler是request/reply在默认情况下.

要达到您的just move要求,您应该添加:

handler.setExpectReply(false);

该组件的代码如下所示:

if (!this.expectReply) {
    return null;
}

if (resultFile != null) {
    if (originalFileFromHeader == null && payload instanceof File) {
        return this.getMessageBuilderFactory().withPayload(resultFile)
                    .setHeader(FileHeaders.ORIGINAL_FILE, payload);
    }
}
return resultFile;

因此,它尝试发送resultFile到outputChannel端点@ServiceActivator.由于您没有这样的选项且没有replyChannel标题,因此您最终会遇到该异常.