Checking if file is completely written

Does the producer process close the file when its finished writing? If so, trying to open the file in the consumer process with an exclusive lock will fail if the producer process is still producing.

I got the solution working:

private boolean isCompletelyWritten(File file) {
    RandomAccessFile stream = null;
    try {
        stream = new RandomAccessFile(file, "rw");
        return true;
    } catch (Exception e) {
        log.info("Skipping file " + file.getName() + " for this iteration due it's not completely written");
    } finally {
        if (stream != null) {
            try {
                stream.close();
            } catch (IOException e) {
                log.error("Exception during closing file " + file.getName());
            }
        }
    }
    return false;
}

Thanks to @cklab and @Will and all others who suggested to look in "exclusive lock" way. I just posted code here to make other interested in people use it. I believe the solution with renaming suggested by @tigran also works but pure Java solution is preferable for me.

P.S. Initially I used FileOutputStream instead of RandomAccessFile but it locks file being written.

One simple solution I've used in the past for this scenario with Windows is to use boolean File.renameTo(File) and attempt to move the original file to a separate staging folder:

boolean success = potentiallyIncompleteFile.renameTo(stagingAreaFile);

If success is false, then the potentiallyIncompleteFile is still being written to.