有时候写代码，因为一个小功能而浪费时间实在得不偿失，这里上传一份检测URL是否有效的代码，短小精悍，希望对大家有帮助。-Sometimes writing code, because a small feature is worth the candle and a waste of time, upload a test URL where the code is valid, dapper, we want to help.