code: public void createPadFile(File padFile, long size) {
  		OutputStream os = null;
  		try {
  			os = new BufferedOutputStream(new FileOutputStream(padFile), ioBufferSize);
  			long totalSize = 0;
  			long bytesLeft;
  			byte[] randomBytes = new byte[workBufferSize];
  			while (totalSize < size) {
  				random.nextBytes(randomBytes);
  				bytesLeft = size - totalSize;
  				if(bytesLeft < workBufferSize) {
  					os.write(randomBytes, 0, (int) bytesLeft);
  					totalSize += bytesLeft;
  				} else {
  					os.write(randomBytes);
  					totalSize += workBufferSize;
  				}
  			}
  			os.flush();
  		} catch(IOException e) {
  			throw new RuntimeException(e);
  		} finally {
  			if(os != null) {
  				try {
  					os.close();
  				} catch(IOException e) {
  					e.printStackTrace();
  				}
  			}
  		}
  	}
docs: <p>Creates a padfile containing random bytes.</p>
  @param padFile
  @param size