Apache Camel FTP 错误

Question

我正在编写一段代码，将 FTP 输入路由到 bean 进程，然后路由到 FTP 输出。该过程大约需要 15 分钟才能完成，完成后，Camel 会尝试从 FTP 输入路径中删除输入文件。目前FTP服务器报错：

13 Jan 2015 18:21:26 DEBUG org.apache.camel.component.file.remote.FtpOperations.deleteFile - Deleting file: ../flex-brazil/Portal_Forn/request_appr/364/NF_4.txt
13 Jan 2015 18:21:26  WARN org.slf4j.helpers.MarkerIgnoringBase.warn - Error during commit. Exchange[org.apache.camel.component.file.GenericFileMessage@3207779]. Caused by: [org.apache.camel.component.file.GenericFileOperationFailedException - File operation failed: 421 Timeout (900 seconds): closing control connection.
FTP response 421 received.  Server closed connection.. Code: 421]
org.apache.camel.component.file.GenericFileOperationFailedException: File operation failed: 421 Timeout (900 seconds): closing control connection.
FTP response 421 received.  Server closed connection.. Code: 421
at org.apache.camel.component.file.remote.FtpOperations.getCurrentDirectory(FtpOperations.java:701)
at org.apache.camel.component.file.remote.FtpOperations.deleteFile(FtpOperations.java:224)
at org.apache.camel.component.file.strategy.GenericFileDeleteProcessStrategy.commit(GenericFileDeleteProcessStrategy.java:71)
at org.apache.camel.component.file.GenericFileOnCompletion.processStrategyCommit(GenericFileOnCompletion.java:124)
at org.apache.camel.component.file.GenericFileOnCompletion.onCompletion(GenericFileOnCompletion.java:80)
at org.apache.camel.component.file.GenericFileOnCompletion.onComplete(GenericFileOnCompletion.java:54)
at org.apache.camel.util.UnitOfWorkHelper.doneSynchronizations(UnitOfWorkHelper.java:100)
at org.apache.camel.impl.DefaultUnitOfWork.done(DefaultUnitOfWork.java:228)
at org.apache.camel.util.UnitOfWorkHelper.doneUow(UnitOfWorkHelper.java:61)
at org.apache.camel.processor.CamelInternalProcessor$UnitOfWorkProcessorAdvice.after(CamelInternalProcessor.java:613)
at org.apache.camel.processor.CamelInternalProcessor$UnitOfWorkProcessorAdvice.after(CamelInternalProcessor.java:581)
at org.apache.camel.processor.CamelInternalProcessor$InternalCallback.done(CamelInternalProcessor.java:240)
at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:173)
at org.apache.camel.component.file.GenericFileConsumer.processExchange(GenericFileConsumer.java:401)
at org.apache.camel.component.file.remote.RemoteFileConsumer.processExchange(RemoteFileConsumer.java:99)
at org.apache.camel.component.file.GenericFileConsumer.processBatch(GenericFileConsumer.java:201)
at org.apache.camel.component.file.GenericFileConsumer.poll(GenericFileConsumer.java:165)
at org.apache.camel.impl.ScheduledPollConsumer.doRun(ScheduledPollConsumer.java:187)
at org.apache.camel.impl.ScheduledPollConsumer.run(ScheduledPollConsumer.java:114)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:304)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:178)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.commons.net.ftp.FTPConnectionClosedException: FTP response 421 received.  Server closed connection.
at org.apache.commons.net.ftp.FTP.__getReply(FTP.java:367)
at org.apache.commons.net.ftp.FTP.__getReply(FTP.java:294)
at org.apache.commons.net.ftp.FTP.sendCommand(FTP.java:483)
at org.apache.commons.net.ftp.FTP.sendCommand(FTP.java:608)
at org.apache.commons.net.ftp.FTP.sendCommand(FTP.java:582)
at org.apache.commons.net.ftp.FTP.pwd(FTP.java:1454)
at org.apache.commons.net.ftp.FTPClient.printWorkingDirectory(FTPClient.java:2658)
at org.apache.camel.component.file.remote.FtpOperations.getCurrentDirectory(FtpOperations.java:697)
... 25 more

有什么参数可以教Camel发送keepalives到FTP服务器来避免这种情况吗？

Answer 1

我建议把整个过程分成两条路线：

1. Reader Route：仅从 FTP 服务器读取文件。
2. Process and Writer Route：此路由处理传入的消息并将响应写入 FTP 服务器

这样做的好处是，读取和删除后连接会被关闭，无一例外。 当一条新消息将被写回服务器时，将创建一个新连接。

当进程异步时，第一条路由只能关闭连接。为此，您可以使用队列进行读取和写入，例如seda 或 jms。

Answer 2

您可以考虑设置更大的超时选项 - 默认为 30 秒。

将超时设置为 15 分钟：ftp://user@host?timeout=900000

但请记住，FTP 服务器可能会关闭连接。