正则表达式很常用，下面是我整理的匹配URL或者网址的一些表达式：
((https|http|ftp|rtsp|mms):/{2})?www.[a-z0-9]{1,}.(com|cn)(/[a-z0-9]{1,}(.[a-z]{1,})*){0,}
测试模拟
String pattern = "((https|http|ftp|rtsp|mms):/{2})?www.[a-z0-9]{1,}.(com|cn)(/[a-z0-9]{1,}(.[a-z]{1,})*){0,}");
Pattern r = Pattern.compile(pattern);
String url1 = "www.hao123.com";
String url2 = "www.baidu.com/asd123.html";
String url4 = "www.baidu.com/5/qwe";
String url3 = "www.baidu.com/";
System.out.println(url1 + r.matcher(url1).matches());
System.out.println(url2 + r.matcher(url2).matches());
System.out.println(url3 + r.matcher(url3).matches());
System.out.println(url4 + r.matcher(url4).matches());
www.hao123.com true www.baidu.com/asd123.html true www.baidu.com/5/qwe true www.baidu.com/ false
总结
限制了www.(xxx).com(/xxx). www开头，com结尾，二级路由加斜杠
