[CAMEL-7451] FTP consumer sometimes throws NullPointerException

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.13.0
• Fix Version/s: 2.12.4, 2.13.2, 2.14.0
• Component/s: camel-ftp

Environment

Camel 2.13.1
Oracle jdk 1.7.0_55
Debian GNU/Linux oldstable
Remote ftp server IIS on Windows 2000 server

• Estimated Complexity: Unknown
• Assignee: Claus Ibsen
• Reporter: Alberto Brosich
• Created: 21/May/14 06:43
• Updated: 23/May/14 07:05
• Resolved: 23/May/14 07:05

Description

I have an exception from a ftp consumer only for few files.

• It happens on few files (2 or 3). Remote directory contains many files
  (many thousand)

• These few files have the same ownership and permissions of the others
  and are not empty

• I stopped the application that create the files, to avoid any possible
  lock (anyway, I can modify them without problems)

• I tried to copy and rename the files, removing the old one, (to create
  a completely new one) without success

• Looking at the source code in
  FtpChangedExclusiveReadLockStrategy.java, the error happens getting the
  timestamp of the file:

  for (FTPFile f : files) {
      if (f.getName().equals(file.getFileNameOnly())) {
          newLastModified = f.getTimestamp().getTimeInMillis();
          newLength = f.getSize();
      }
  }
  

• Nothing useful in the logs of the ftp server

Follow a trace log and the exception regarding one of those files:

2014-05-19 16:21:32,298 TRACE FtpChangedExclusiveReadLockStrategy -
Waiting for exclusive read lock to file:
RemoteFile[/dwrg1/moved/DWRG1_2014-03-30T01h30Z.xml]
2014-05-19 16:21:32,298 TRACE FtpChangedExclusiveReadLockStrategy -
Waiting for exclusive read lock to file:
RemoteFile[/dwrg1/moved/DWRG1_2014-03-30T01h30Z.xml]
2014-05-19 16:21:32,298 TRACE FtpChangedExclusiveReadLockStrategy -
Waiting for exclusive read lock to file:
RemoteFile[/dwrg1/moved/DWRG1_2014-03-30T01h30Z.xml]
2014-05-19 16:21:32,299 TRACE FtpChangedExclusiveReadLockStrategy -
Using fast exists to update file information for
RemoteFile[/dwrg1/moved/DWRG1_2014-03-30T01h30Z.xml]
2014-05-19 16:21:32,299 TRACE FtpChangedExclusiveReadLockStrategy -
Using fast exists to update file information for
RemoteFile[/dwrg1/moved/DWRG1_2014-03-30T01h30Z.xml]
2014-05-19 16:21:32,640 TRACE FtpChangedExclusiveReadLockStrategy - List
files /dwrg1/moved/DWRG1_2014-03-30T01h30Z.xml found 1 files
2014-05-19 16:21:32,640 TRACE FtpChangedExclusiveReadLockStrategy - List
files /dwrg1/moved/DWRG1_2014-03-30T01h30Z.xml found 1 files
2014-05-19 16:21:32,650 WARN  FtpConsumer -
Endpoint[ftp://[e-mail]//dwrg1/moved?delay=60000&disconnect=true&fastExistsCheck=true&idempotent=true&idempotentKey=%24%7Bfile%3Aname%7D-%24%7Bfile%3Amodified%7D-%24%7Bfile%3Asize%7D&idempotentRepository=%23fileStore&include=DWRG1.*%5C.xml&maxMessagesPerPoll=10&noop=true&password=xxxxxx&readLock=changed&sortBy=file%3Amodified] cannot begin processing file: RemoteFile[/dwrg1/moved/DWRG1_2014-03-30T01h30Z.xml] due to: null. Caused by: [java.lang.NullPointerException - null]
java.lang.NullPointerException
        at
org.apache.camel.component.file.remote.strategy.FtpChangedExclusiveReadLockStrategy.acquireExclusiveReadLock(FtpChangedExclusiveReadLockStrategy.java:83)
        at
org.apache.camel.component.file.strategy.GenericFileProcessStrategySupport.begin(GenericFileProcessStrategySupport.java:49)
        at
org.apache.camel.component.file.strategy.GenericFileRenameProcessStrategy.begin(GenericFileRenameProcessStrategy.java:35)
        at
org.apache.camel.component.file.GenericFileConsumer.processExchange(GenericFileConsumer.java:326)
        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)