code: static public void emptyDirectory(File dir) throws Exception {
  		String[] fileNames = dir.list();
  		if( null != fileNames ) {
  			for(String fileName : fileNames){
  				File file = new File(dir,fileName);
  				if( file.isDirectory() ) {
  					emptyDirectory(file);
  				}
  				boolean deleted = false;
  				try {
  					deleted = file.delete();
  				} catch(Exception e) {
  					throw new Exception("Unable to delete: "+file.getAbsolutePath(),e);
  				}
  				if( !deleted ){
  					throw new Exception("Unable to delete: "+file.getAbsolutePath());
  				}
  			}
  		}
  	}
docs: Given a directory, removes all the content found in the directory.
  @param dir The directory to be emptied
  @throws Exception