常用正则

String regEx = "^(http|https|ftp)\\://([a-zA-Z0-9\\.\\-]+(\\:[a-zA-"   
           + "Z0-9\\.&%\\$\\-]+)*@)?((25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{"   
           + "2}|[1-9]{1}[0-9]{1}|[1-9])\\.(25[0-5]|2[0-4][0-9]|[0-1]{1}"   
           + "[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\\.(25[0-5]|2[0-4][0-9]|"   
           + "[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\\.(25[0-5]|2[0-"   
           + "4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[0-9])|([a-zA-Z0"   
           + "-9\\-]+\\.)*[a-zA-Z0-9\\-]+\\.[a-zA-Z]{2,4})(\\:[0-9]+)?(/"   
           + "[^/][a-zA-Z0-9\\.\\,\\?\\‘\\\\/\\+&%\\$\\=~_\\-@]*)*$";