How to cancel downloading process in JAVA ftp?

Question

I tried to write a java ftp client to transfer files within our network. One of very usefully function I want to add is to cancel the transfer while files
are downloading or uploading. I can do this on file uploading by closing "ftpclient.put(filename) methods at anytime, but have trouble on closing "ftpClient.get(remoteFilename)". When I tried to close it by using "in.close()", the program stucked. I even tried to kill the thread, but no luck. Can any one give me a hint? Here is the code:
protected void downloadfile ()
byte [] buffer = new byte[BUFFER_SIZE];
try{
FileOutputStream out = new FileOutputStream(Localfilename);
InputStream in = ftpClient.get(remoteFilename); //downloading
// Write to local file
while (true && !cancelORnot)
// write to file
} catch ( Exception ex) { }
finally
try {
if (out ! = null)
out.close(); // this can be closed at any time
if (in != null)
in.close(); // This one stucked if it is in the middle
// of downloading and can not disconnect to the
// ftp server
catch ( IOException ex)
}

Answer 1

How does the ftpClient.get("fileName") work? Also, are you running everything in the EventDispatchThread? If your running everything in the EventDispatchThread then ftpClient.get() will need to finish before an event can be handled.
If thats the case, you could use a SwingWorker to do the downloading so that the Event Thread is available to handle the cancel event.