Servlet返回数据在JS中的两种解析方式：JSON与XML

{ "firstName":"John" , "lastName":"Doe" }

resp.getWriter().write("{name:"+u.getHeroName()+ 
                ",lifenum:"+u.getLifeNum()+
                ",type:"+u.getType()+
                ",desc:"+u.getDesc()
        +"}")

<%@ page language="java" contentType="text/xml; charset=utf-8"%>
<user>
  <name>李四</name>
  <pwd>123</pwd>
</user>

<%@ page language="java" contentType="text/html; charset=utf-8"
  pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<script type="text/javascript">
  function getXML(){
    //创建ajax引擎对象
      var ajax;
      if(window.XMLHttpRequest){//火狐
        ajax=new XMLHttpRequest();
      }else if(window.ActiveXObject){//ie
        ajax=new ActiveXObject("Msxml2.XMLHTTP");
      }
    //复写onreadystatechange
      ajax.onreadystatechange=function(){
        //判断Ajax状态吗
        if(ajax.readyState==4){
          //判断响应状态吗
          if(ajax.status==200){
            //获取响应内容
            var doc=ajax.responseXML;
            //处理响应内容
              //获取元素对象
              alert(doc.getElementsByTagName("name")[0].innerHTML);
          }
        }
      }
    //发送请求
      ajax.open("get","xml.jsp",true);
      ajax.send(null);
  }


</script>
</head>
<body>
  <h3>XML数据格式学习</h3>
  <hr>
  <input type="button" value="测试XML" onclick="getXML()" />
  
  
  
</body>
</html>