How to move files using ExpressionEvaluatingRequestHandlerAdvice

问题

In the manual for ExpressionEvaluatingRequestHandlerAdvice, it clearly says, A typical use case for this advice might be with an <ftp:outbound-channel-adapter/>, perhaps to move the file to one directory if the transfer was successful, or to another directory if it fails.

But I cannot figure out expression to move payload from current directory to another one.

This example just deletes or renames the file:

<bean class="org.springframework.integration.handler.advice.ExpressionEvaluatingRequestHandlerAdvice">
    <property name="onSuccessExpression" value="payload.delete()" />
    <property name="successChannel" ref="afterSuccessDeleteChannel" />
    <property name="onFailureExpression" value="payload.renameTo(new java.io.File(payload.absolutePath + '.failed.to.send'))" />
    <property name="failureChannel" ref="afterFailRenameChannel" />
</bean>

How to achieve this?

Edit

As per Gary's suggestion, this is the new try:

Managed to change the expression to "T(java.nio.file.Files).move(payload.path, new java.io.File(new java.io.File('sent'), payload.name).path, T(java.nio.file.StandardCopyOption).REPLACE_EXISTING)", but still get the error Method move(java.lang.String,java.lang.String,java.nio.file.Standar‌​dCopyOption) cannot be found on java.nio.file.Files type

The code is,

@Bean
    @ServiceActivator(inputChannel = "toSftpChannel", adviceChain = "expressionAdvice")
    public MessageHandler uploadHandler() {
        SftpMessageHandler handler = new SftpMessageHandler(sftpSessionFactory());
        handler.setRemoteDirectoryExpression(new LiteralExpression(outRemoteDirectory));
        handler.setFileNameGenerator(new FileNameGenerator() {

            @Override
            public String generateFileName(Message<?> message) {
                if (message.getPayload() instanceof File) {
                    return ((File) message.getPayload()).getName();
                } else {
                    throw new IllegalArgumentException("File expected as payload.");
                }
            }

        });
        return handler;
    }

    @MessagingGateway()
    public interface UploadGateway {

        @Gateway(requestChannel = "toSftpChannel")
        void upload(File file);

    }

@Bean
    public String onUploadSuccessExpression() {
        return "T(java.nio.file.Files).move(payload.path, new java.io.File(new java.io.File('sent'), payload.name).path, T(java.nio.file.StandardCopyOption).REPLACE_EXISTING)";
    }

@Bean
    public String onUploadFailedExpression() {
        return "payload";
    }

@Bean
    public Advice expressionAdvice() {
        ExpressionEvaluatingRequestHandlerAdvice expressionEvaluatingRequestHandlerAdvice = new ExpressionEvaluatingRequestHandlerAdvice();
        expressionEvaluatingRequestHandlerAdvice.setOnSuccessExpressionString(onUploadSuccessExpression());
        expressionEvaluatingRequestHandlerAdvice.setSuccessChannelName("uploadSuccessChannel");
        expressionEvaluatingRequestHandlerAdvice.setOnFailureExpressionString(onUploadFailedExpression());
        expressionEvaluatingRequestHandlerAdvice.setFailureChannelName("uploadFailedChannel");
        expressionEvaluatingRequestHandlerAdvice.setTrapException(true);
        expressionEvaluatingRequestHandlerAdvice.setPropagateEvaluationFailures(true);
        return expressionEvaluatingRequestHandlerAdvice;
    }

The upload method from UploadGateway is called.

The stack trace is,

"main@1" prio=5 tid=0x1 nid=NA runnable
  java.lang.Thread.State: RUNNABLE
      at org.springframework.integration.handler.advice.ExpressionEvaluatingRequestHandlerAdvice.evaluateSuccessExpression(ExpressionEvaluatingRequestHandlerAdvice.java:241)
      at org.springframework.integration.handler.advice.ExpressionEvaluatingRequestHandlerAdvice.doInvoke(ExpressionEvaluatingRequestHandlerAdvice.java:214)
      at org.springframework.integration.handler.advice.AbstractRequestHandlerAdvice.invoke(AbstractRequestHandlerAdvice.java:70)
      at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
      at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
      at com.sun.proxy.$Proxy81.handleRequestMessage(Unknown Source:-1)
      at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.doInvokeAdvisedRequestHandler(AbstractReplyProducingMessageHandler.java:127)
      at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:112)
      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:148)
      at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:121)
      at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:89)
      at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:423)
      at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:373)
      at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:115)
      at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:45)
      at org.springframework.messaging.core.AbstractMessageSendingTemplate.send(AbstractMessageSendingTemplate.java:105)
      at org.springframework.messaging.core.AbstractMessageSendingTemplate.convertAndSend(AbstractMessageSendingTemplate.java:143)
      at org.springframework.messaging.core.AbstractMessageSendingTemplate.convertAndSend(AbstractMessageSendingTemplate.java:135)
      at org.springframework.integration.gateway.MessagingGatewaySupport.send(MessagingGatewaySupport.java:392)
      at org.springframework.integration.gateway.GatewayProxyFactoryBean.invokeGatewayMethod(GatewayProxyFactoryBean.java:481)
      at org.springframework.integration.gateway.GatewayProxyFactoryBean.doInvoke(GatewayProxyFactoryBean.java:433)
      at org.springframework.integration.gateway.GatewayProxyFactoryBean.invoke(GatewayProxyFactoryBean.java:424)
      at org.springframework.integration.gateway.GatewayCompletableFutureProxyFactoryBean.invoke(GatewayCompletableFutureProxyFactoryBean.java:65)
      at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
      at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
      at com.sun.proxy.$Proxy87.upload(Unknown Source:-1)

回答1:

If the new directory is on the same disk as the old one, in the 'onSuccessExpression', simply use payload.renameTo(...) similar to the way the sample does in the onFailureExpression.

`payload.renameTo(new java.io.File(new File('newDir'), payload.name))`

Creates a file with the payload's name to a directory newDir (which must exist).

If you are JDK 7 or above use...

T(java.nio.file.Files).move(payload.path, new java.io.File(new File('newDir'), payload.name).path)

...instead.

This will handle the situation of the new directory being on a different disk (which a simple File.renameTo() will not).

If you are still on JDK 6 and the new directory might be on a different disk you will need to use onSuccessExpression=payload and subscribe a service activator to the successChannel to manipulate the file itself, perhaps using Spring's FileCopyUtils.

来源：https://stackoverflow.com/questions/47742953/how-to-move-files-using-expressionevaluatingrequesthandleradvice