java - How to find out why renameTo() failed?

Question

I am using WinXP. I use java to generate a list of files. The file will be created as abc.txt.temp at first, and after completing the generation, it will be renamed to abc.txt.

However, when i generating the files, some of the files failed to be renamed. It happen randomly.

Is there anyway to find out the reason why it failed?

int maxRetries = 60;
logger.debug("retry");
while (maxRetries-- > 0)
{
    if (isSuccess = file.renameTo(file2))
    {
        break;
    }
    try
    {
        logger.debug("retry " + maxRetries);
        Thread.sleep(1000);
    }
    catch (InterruptedException e)
    {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }   
}

//file.renameTo(file2);
Thread.currentThread().getThreadGroup().getParent().list();

And the result:

[DEBUG][2009-08-25 08:57:52,386] - retry 1
[DEBUG][2009-08-25 08:57:53,386] - retry 0
java.lang.ThreadGroup[name=system,maxpri=10]
    Thread[Reference Handler,10,system]
    Thread[Finalizer,8,system]
    Thread[Signal Dispatcher,9,system]
    Thread[Attach Listener,5,system]
    java.lang.ThreadGroup[name=main,maxpri=10]
        Thread[main,5,main]
        Thread[log4j mail appender,5,main]
[DEBUG][2009-08-25 08:57:54,386] - isSuccess:false

I would like to know a systematic approach to figure out the reason. Thanks.

Answer 1

It's possible that the reason that renaming failed is that the file is still open. Even if you are closing the file, it could be held open because of (for example):

1. A file handle is inherited by a subprocess of your process
2. An anti-virus program is scanning the file for viruses, and so has it open
3. An indexer (such as Google Desktop or the Windows indexing service) has the file open

To help find out what is keeping the file open, use tools such as FileMon and Handle.

Update: A tool such as Unlocker may not help, if the file is only held open for a very short time (as would be the case for an anti-virus scan). However, if javaw.exe is shown as having the file open, that's your problem right there.