Java截取url参数的值

public static void main(String[] args){
        String Url = "http://localhost:8180/guozhi/login.jsp?preappid=guozhi&preownerid=1234";

        System.out.println("参数preappid的值是："+getUrl(Url,"preappid"));
        System.out.println("参数preownerid的值是："+getUrl(Url,"preownerid"));
    }
    public static String getUrl(String url, String name){
        url +="&";
        String pattern = "(\\?|&){1}#{0,1}"  + name + "=[a-zA-Z0-9]*(&{1})";
        Pattern r = Pattern.compile(pattern);
        Matcher matcher = r.matcher(url);
        if(matcher.find()){
//            System.out.println(matcher.group(0));
            return matcher.group(0).split("=")[1].replace("&","");
        }else{
            return null;
        }
    }