code: private static void checkFile(File file) {
  		if (false == file.exists()) {
  			throw new UtilException("File [{}] not exist !", file.getAbsolutePath());
  		}
  		if (false == file.isFile()) {
  			throw new UtilException("Path [{}] is not a file !", file.getAbsolutePath());
  		}
  	}
docs: 检查文件有效性
  
  @param file 文件