Question

我在从特定工作站上传文件（使用ftp4j库）时收到一个奇怪的异常。

文件上传后（100％）我收到读取超时异常。这是：

2015-03-20 18:14:43 INFO  TranferFileFtp4j:760 - FTP Server supports resume. Trying to upload file
2015-03-20 18:14:43 INFO  Ftp4jListener:38 - TRANSFER-STATUS: File transfer started
2015-03-20 18:14:43 INFO  Ftp4jListener:47 - File: 152818571.zip | Bytes transfered 65536 Percentage: 0.024173772%
...
2015-03-20 18:20:08 INFO  Ftp4jListener:47 - File: 153740599.zip | Bytes transfered 244383744 Percentage: 99.89077%
2015-03-20 18:20:08 INFO  Ftp4jListener:47 - File: 153740599.zip | Bytes transfered 244449280 Percentage: 99.91756%
2015-03-20 18:20:08 INFO  Ftp4jListener:47 - File: 153740599.zip | Bytes transfered 244514816 Percentage: 99.94434%
2015-03-20 18:20:08 INFO  Ftp4jListener:47 - File: 153740599.zip | Bytes transfered 244580352 Percentage: 99.97113%
2015-03-20 18:20:08 INFO  Ftp4jListener:47 - File: 153740599.zip | Bytes transfered 244645888 Percentage: 99.99792%
2015-03-20 18:20:08 INFO  Ftp4jListener:47 - File: 153740599.zip | Bytes transfered 244650979 Percentage: 100.0%
2015-03-20 18:20:18 INFO  TranferFileFtp4j:803 - Failed to send File! IOException other exceptionRead timed out - null
java.net.SocketTimeoutException: Read timed out
    at java.net.SocketInputStream.socketRead0(Native Method)
    at java.net.SocketInputStream.read(Unknown Source)
    at java.net.SocketInputStream.read(Unknown Source)
    at sun.security.ssl.InputRecord.readFully(Unknown Source)
    at sun.security.ssl.InputRecord.read(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readDataRecord(Unknown Source)
    at sun.security.ssl.AppInputStream.read(Unknown Source)
    at sun.nio.cs.StreamDecoder.readBytes(Unknown Source)
    at sun.nio.cs.StreamDecoder.implRead(Unknown Source)
    at sun.nio.cs.StreamDecoder.read(Unknown Source)
    at sun.nio.cs.StreamDecoder.read0(Unknown Source)
    at sun.nio.cs.StreamDecoder.read(Unknown Source)
    at java.io.InputStreamReader.read(Unknown Source)
    at it.sauronsoftware.ftp4j.NVTASCIIReader.readLine(NVTASCIIReader.java:105)
    at it.sauronsoftware.ftp4j.FTPCommunicationChannel.read(FTPCommunicationChannel.java:142)
    at it.sauronsoftware.ftp4j.FTPCommunicationChannel.readFTPReply(FTPCommunicationChannel.java:187)
    at it.sauronsoftware.ftp4j.FTPClient.upload(FTPClient.java:2797)
    at it.sauronsoftware.ftp4j.FTPClient.upload(FTPClient.java:2586)
    at com.npap.network.TranferFileFtp4j.uploadFileFtps5(TranferFileFtp4j.java:765)
    at com.npap.utils.ProcessDicomFiles.sendZippFiles(ProcessDicomFiles.java:215)
    at com.npap.scheduler.MainJob.execute(MainJob.java:97)
    at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
    at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:573)
    java.net.SocketTimeoutException: Read timed out
    at java.net.SocketInputStream.socketRead0(Native Method)
    at java.net.SocketInputStream.read(Unknown Source)
    at java.net.SocketInputStream.read(Unknown Source)
    at sun.security.ssl.InputRecord.readFully(Unknown Source)
    at sun.security.ssl.InputRecord.read(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readDataRecord(Unknown Source)
    at sun.security.ssl.AppInputStream.read(Unknown Source)
    at sun.nio.cs.StreamDecoder.readBytes(Unknown Source)
    at sun.nio.cs.StreamDecoder.implRead(Unknown Source)
    at sun.nio.cs.StreamDecoder.read(Unknown Source)
    at sun.nio.cs.StreamDecoder.read0(Unknown Source)
    at sun.nio.cs.StreamDecoder.read(Unknown Source)
    at java.io.InputStreamReader.read(Unknown Source)
    at it.sauronsoftware.ftp4j.NVTASCIIReader.readLine(NVTASCIIReader.java:105)
    at it.sauronsoftware.ftp4j.FTPCommunicationChannel.read(FTPCommunicationChannel.java:142)
    at it.sauronsoftware.ftp4j.FTPCommunicationChannel.readFTPReply(FTPCommunicationChannel.java:187)
    at it.sauronsoftware.ftp4j.FTPClient.disconnect(FTPClient.java:1133)
    at com.npap.network.TranferFileFtp4j.uploadFileFtps5(TranferFileFtp4j.java:826)
    at com.npap.utils.ProcessDicomFiles.sendZippFiles(ProcessDicomFiles.java:215)
    at com.npap.scheduler.MainJob.execute(MainJob.java:97)
    at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
    at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:573)

以下是代码：

ftpClient = Ftp4jUtility.ftpsConnect(SERVER_MACHINE, PORT, SERVER_USERNAME, SERVER_PASSWORD, stdId);
ftpClient.changeDirectory(config.getFtpRemoteFolderUploads());

 if(ftpClient.isResumeSupported()) {
     ftpClient.upload(localFile, writtenBytes, new Ftp4jListener(localFile.length(), localFile.getName()));
 } else {
     ftpClient.upload(localFile, new Ftp4jListener(localFile.length(), localFile.getName()));
 }

completed = true;

} catch (FTPAbortedException e) {
    ....
    break;
} catch (FTPDataTransferException ex1) {
    studyDetailsDAO.updateStudyIsInProgress(stdId, false);
    ex1.printStackTrace();
    ....
} catch (FTPException ex1) {
   ex1.printStackTrace();
   ....
} catch (FTPIllegalReplyException ex1) {
   ex1.printStackTrace();
   ...
} catch (IOException ex1) {
   log.info("Failed to send File! IOException " + ex1.getMessage());
   ex1.printStackTrace();
} catch (IllegalStateException ex1) {
   ...
} finally {
   if(ftpClient!=null && ftpClient.isConnected()) {
       try {
           ftpClient.disconnect(true); 
       } catch (Throwable t) {
           t.printStackTrace();
       }
   }
}

我收到此异常：IOException - 读取超时！有什么想法导致这个？或者如何进行调试？

奇怪的是所有ftp操作都在运行！我也可以启动并实际上传文件，但是在ftpClient.upload操作结束时我才收到这个时间！

我还检查过，发现我从特定工作站遇到这个特殊问题。我甚至尝试使用filezilla上传文件，我收到类似的异常（读取超时）。所以我想这是网络或防火墙问题......有什么想法吗？

有什么想法吗？

Answer 1

可能出现的问题

FTP协议在客户端和服务器之间使用单独的控制和数据TCP连接。在文件传输期间，数据连接正忙，但控制连接处于空闲状态。根据您的日志，转移需要15分钟。这意味着控制连接在这段时间内处于空闲状态。某些防火墙或网络路由器可以在一段时间内断开连接而不进行任何活动。看起来就是这种情况，因为readFTPReply尝试从控件连接中读取并抛出＆＃34; Read timed out＆＃34; 。

如何调试

您可以通过Wireshark或tcpdump在客户端转储流量，并尝试找出控制连接断开的原因。

如何修复

我可以看到两种解决问题的方法：

您可以通过控制连接ping服务器发送NOOP命令，以便在传输过程中进行一些活动，并在防火墙/路由器中重置连接的空闲计时器。我不确定ftp4j是否能做到这一点。但您可以切换到Apache FTPClient并使用setControlKeepAliveTimeout。
您可以尝试更新/更改防火墙/路由器。

ftp4j读取上传文件后超时

1 个答案: