java url移除某个参数 java从url字符串中截取域名

方法1.获取顶级域名

public  String getDomainForUrl(String url){

        String domainUrl = null;
        if (url == null) {
            return null;
        } else {
            Pattern p = Pattern.compile("(?<=http://|\\.)[^.]*?\\.(com|cn|net|org|biz|info|cc|tv)",Pattern.CASE_INSENSITIVE);
            Matcher matcher = p.matcher(url);
            matcher.find();
            domainUrl = matcher.group();
            return domainUrl;
        }
    }

方法2:获取域名全称

public  String getDomainForUrl(String url){
        //使用正则表达式过滤，
        String re = "((http|ftp|https)://)(([a-zA-Z0-9._-]+)|([0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}))(([a-zA-Z]{2,6})|(:[0-9]{1,4})?)";
        String str = "";
        // 编译正则表达式
        Pattern pattern = Pattern.compile(re);
        // 忽略大小写的写法
        // Pattern pat = Pattern.compile(regEx, Pattern.CASE_INSENSITIVE);
        Matcher matcher = pattern.matcher(url);
        //若url==http://127.0.0.1:9040或www.baidu.com的，正则表达式表示匹配
        if (matcher.matches()) {
            str = url;
        } else {
            String[] split2 = url.split(re);
            if (split2.length > 1) {
                String substring = url.substring(0, url.length() - split2[1].length());
                str = substring;
            } else {
                str = split2[0];
            }
        }
        return str;
    }