Client window file submission entries not removed after each file is submitted

[jiajunmao]

Describe the bug
Client window file submission entries not removed after each file is submitted

To Reproduce
Steps to reproduce the behavior:

1. Run the client window class under com.khpc.client
2. Choose some files
3. Click submit (configure the environment and start the server first)
4. See error

Expected behavior
Each entry is removed when that entry is submitted

Code

private void submit() throws UnknownHostException, IOException, InterruptedException {
		// The list that contains all the file path that is going to be submitted
		List<File> fileList = new ArrayList<File>();

		for (int i = 0; i < model.getSize(); i++) {
			fileList.add((File) (model.getElementAt(i)));
		}

		for (File file : fileList) {
			FileSendCoordinator.sendFileOnce(file, servIpAddr);
			model.removeElementAt(0);
		}
		
		model.clear();
	}