code: public static Resource getTempFile(String extension, boolean touch) throws IOException {
  	String filename = CreateUniqueId.invoke();
  	if (!StringUtil.isEmpty(extension, true)) {
  	    if (extension.startsWith(".")) filename += extension;
  	    else filename += "." + extension;
  	}
  	Resource file = getTempDirectory().getRealResource(filename);
  	if (touch) ResourceUtil.touch(file);
  	return file;
      }
docs: returns the a unique temp file (with no auto delete)
  
  @param extension
  @return temp directory
  @throws IOException