ip地址验证的正则表达式

String regex = "^(1\\d{2}|2[0-4]\\d|25[0-5]|[1-9]\\d|\\d)\\."

+ "(1\\d{2}|2[0-4]\\d|25[0-5]|[1-9]\\d|\\d)\\."

+ "(1\\d{2}|2[0-4]\\d|25[0-5]|[1-9]\\d|\\d)\\."

+ "(1\\d{2}|2[0-4]\\d|25[0-5]|[1-9]\\d|\\d)$";