AJAX增添用户时-检查用户名是否重复

servlet:checkNamerequest.setCharacterEncoding("UTF-8");String name=request.getParameter("name");name = new String(name.getBytes("ISO-8859-1"),"UTF-8");User user=new UserDao().checkName(name);PrintWriter out=response.getWriter();if(user==null){    out.print("true");    out.flush();    out.close();}else{    out.print("false");    out.flush();    out.close();

JS文件$("[name=addname]").blur(function (){    var value=this.value;    var obj=$(this);    $.ajax({        url:"checkName",    //servlet        type:"post",        data:{"name":value},    //提交的数据,必须是json格式        dataType:"text",     //回传数据的类型有:json/jsonp/xml/text        success:function(type){  //callback 回传函数    成功后回传的数据data            $(".message").remove();            if("true"==type){                obj.after("<span class='message greenMeg'>可以使用</span>");                $("#add").removeAttr("disabled");            }else{                obj.after("<span class='message redMeg'>已被使用</span>");                $("#add").attr("disabled", "disabled");            }        }    });});