code: public static synchronized File createSwapFile(String prefix, String suffix) throws IOException {
  		File swapDir = getSwapDir();
  		File tmpFile = File.createTempFile(prefix, suffix, swapDir);
  		return tmpFile;
  	}
docs: Creates a new, empty swap file, ready for use. It is guaranteed
  that this swap file will be removed from the system either on
  JVM shutdown (Unix platforms) or on subsequent use of this class
  (Win32 platforms).
  @param prefix Prefix to be used for this swap file.
  @param suffix Suffix to be used for this swap file.
  @return A new swap file.
  @throws IOException