当同名文件已经存在时，带有 get 命令的 sftp outbound-gateway 会引发异常

Question

我正在尝试使用 sftp 出站网关从远程 sftp 服务器下载文件。这是网关配置：

<int-sftp:outbound-gateway id="downloadGateway"                 
                command="get" 
                command-options="-P"
                expression="payload.remoteDirectory + payload.filename"
                session-factory="cachingSessionFactory"
                local-directory="downloads"
                auto-create-directory="true"
                use-temporary-file-name="true"
                mode="REPLACE"                  
                local-filename-generator-expression="#remoteFileName + '.' + @currentDate.getDateStr()"
                />

如果已经存在同名的本地文件，我想用新下载的文件替换它。这就是我将模式设置为“REPLACE”的原因。相反，我得到了一个例外：

Caused by: org.springframework.messaging.MessagingException: Local file downloads\myFile.xml.2015-04-14 already exists
at org.springframework.integration.file.remote.gateway.AbstractRemoteFileOutboundGateway.get(AbstractRemoteFileOutboundGateway.java:700)
at org.springframework.integration.file.remote.gateway.AbstractRemoteFileOutboundGateway$2.doInSession(AbstractRemoteFileOutboundGateway.java:436)
at org.springframework.integration.file.remote.gateway.AbstractRemoteFileOutboundGateway$2.doInSession(AbstractRemoteFileOutboundGateway.java:432)
at org.springframework.integration.file.remote.RemoteFileTemplate.execute(RemoteFileTemplate.java:334)
at org.springframework.integration.file.remote.gateway.AbstractRemoteFileOutboundGateway.doGet(AbstractRemoteFileOutboundGateway.java:432)
at org.springframework.integration.file.remote.gateway.AbstractRemoteFileOutboundGateway.handleRequestMessage(AbstractRemoteFileOutboundGateway.java:394)
at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:99)
at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:78)
at org.springframework.integration.handler.MessageHandlerChain$1.send(MessageHandlerChain.java:123)
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:95)
at org.springframework.integration.handler.AbstractMessageProducingHandler.sendOutput(AbstractMessageProducingHandler.java:248)
at org.springframework.integration.handler.AbstractMessageProducingHandler.produceOutput(AbstractMessageProducingHandler.java:171)
at org.springframework.integration.handler.AbstractMessageProducingHandler.sendOutputs(AbstractMessageProducingHandler.java:119)
at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:105)
at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:78)
at org.springframework.integration.handler.MessageHandlerChain$1.send(MessageHandlerChain.java:123)
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:95)
at org.springframework.integration.handler.AbstractMessageProducingHandler.sendOutput(AbstractMessageProducingHandler.java:248)
at org.springframework.integration.handler.AbstractMessageProducingHandler.produceOutput(AbstractMessageProducingHandler.java:171)
at org.springframework.integration.splitter.AbstractMessageSplitter.produceOutput(AbstractMessageSplitter.java:129)
at org.springframework.integration.handler.AbstractMessageProducingHandler.sendOutputs(AbstractMessageProducingHandler.java:119)
at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:105)
at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:78)
at org.springframework.integration.handler.MessageHandlerChain$1.send(MessageHandlerChain.java:123)
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:95)
at org.springframework.integration.handler.AbstractMessageProducingHandler.sendOutput(AbstractMessageProducingHandler.java:248)
at org.springframework.integration.handler.AbstractMessageProducingHandler.produceOutput(AbstractMessageProducingHandler.java:171)
at org.springframework.integration.handler.AbstractMessageProducingHandler.sendOutputs(AbstractMessageProducingHandler.java:119)
at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:105)
at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:78)
at org.springframework.integration.handler.MessageHandlerChain.handleMessageInternal(MessageHandlerChain.java:104)
at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:78)
at org.springframework.integration.dispatcher.AbstractDispatcher.tryOptimizedDispatch(AbstractDispatcher.java:116)
... 7 more

当网关与 put 命令一起使用时，我是否正确假设模式属性适用于远程文件？我有什么方法可以通过 sftp 出站网关实现我正在寻找的行为？

Answer 1

有趣；你是这周的第二个请求。

目前，除了自己删除文件（或将文件提取到临时目录，然后使用文件出站适配器移动它们 - 确实提供替换模式）之外，没有其他解决方法.

前几天我开了JIRA Issue来添加这个功能。

实际上，网关上存在mode 属性是一个错误，目前已被忽略。

Answer 2

它是一个旧线程，但如果您正在寻找 mode 的有效值，它们在这里（参考：org.springframework.integration.file.support.FileExistsMode）：

   /**
     * Append data to any pre-existing files; close after each append.
     */
    APPEND,

    /**
     * Append data to any pre-existing files; do not flush/close after
     * appending.
     * @since 4.3
     */
    APPEND_NO_FLUSH,

    /**
     * Raise an exception in case the file to be written already exists.
     */
    FAIL,

    /**
     * If the file already exists, do nothing.
     */
    IGNORE,

    /**
     * If the file already exists, replace it.
     */
    REPLACE;