zoukankan html css js c++ java

ajax 三种数据格式

1.JSON（格式要正确，可以引jar包操作）

servlet代码

 1 package com.hsp.action;
 2 
 3 import java.io.IOException;
 4 import java.io.PrintWriter;
 5 
 6 import javax.json.JsonString;
 7 import javax.servlet.ServletException;
 8 import javax.servlet.annotation.WebServlet;
 9 import javax.servlet.http.HttpServlet;
10 import javax.servlet.http.HttpServletRequest;
11 import javax.servlet.http.HttpServletResponse;
12 
13 /**
14  * Servlet implementation class showCities
15  */
16 @WebServlet("/showCities")
17 public class showCities extends HttpServlet {
18     private static final long serialVersionUID = 1L;
19        
20     /**
21      * @see HttpServlet#HttpServlet()
22      */
23     public showCities() {
24         super();
25         // TODO Auto-generated constructor stub
26     }
27 
28     /**
29      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
30      */
31     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
32         // TODO Auto-generated method stub
33     }
34 
35     /**
36      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
37      */
38     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
39         // TODO Auto-generated method stub
40         response.setContentType("text/xml;charset=utf-8");  
41         response.setHeader("Cache-Control", "no-cache");
42         
43         //接收用户选择的省的名字
44         String shengString=request.getParameter("province");
45         System.out.println(shengString);
46         PrintWriter out=response.getWriter();
47         StringBuilder builder=new StringBuilder();
48       
49 
50         String info="";
51 
52 //        if ("zhejiang".equals(shengString)) {
53 //            System.out.println("浙江");
54 //            info="<province><city>杭州</city><city>温州</city><city>宁波</city></province>";
55 //        }
56 //        else if ("jiangsu".equals(shengString)) {
57 //            System.out.println("江苏");
58 //
59 //            info="<province><city>南京</city><city>徐州</city><city>苏州</city></province>";
60 //        }
61         if ("zhejiang".equals(shengString))
62         {
63             info= "[{"+'"'+"city"+'"'+":"+'"'+"杭州"+'"'+"},{"+'"'+"city"+'"'+":"+'"'+"温州"+'"'+"}]";
64         }
65         else if ("jiangsu".equals(shengString)) {
66             info= "[{"+'"'+"city"+'"'+":"+'"'+"南京"+'"'+"},{"+'"'+"city"+'"'+":"+'"'+"苏州"+'"'+"}]";
67 
68         }
69         System.out.println("{"+'"'+"ins"+'"'+":"+info+"}");
70        builder.append("{"+'"'+"ins"+'"'+":"+info+"}");
71 
72        out.println(builder.toString());
73     }
74 
75 }

jsp代码

  1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
  2 <%
  3 String path = request.getContextPath();
  4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
  5 %>
  6 
  7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
  8 <html>
  9   <head>
 10     <base href="<%=basePath%>">
 11     
 12     <title>My JSP 'Mycity.jsp' starting page</title>
 13     
 14     <meta http-equiv="pragma" content="no-cache">
 15     <meta http-equiv="cache-control" content="no-cache">
 16     <meta http-equiv="expires" content="0">    
 17     <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
 18     <meta http-equiv="description" content="This is my page">
 19     <!--
 20     <link rel="stylesheet" type="text/css" href="styles.css">
 21     -->
 22 
 23   </head>
 24   
 25   <body>
 26   <script type="text/javascript">
 27    //1.创建ajax引擎
 28   function getXmlHttpObject(){
 29   var xmlHttpRequest;
 30   //不同的浏览器获取对象xmlhttprequest对象方法不一样
 31   if(window.ActiveXobject)
 32   {
 33       xmlHttpRequest=new ActiveXobject("Microsoft.XMLHTTP");
 34   }
 35   else
 36   {
 37         xmlHttpRequest=new XMLHttpRequest();
 38   }
 39   return xmlHttpRequest;
 40   }
 41  
 42  //新建myXmlHttpRequest对象
 43  var myXmlHttpRequest="";
 44   
 45   function getCities(){
 46   //创建对象
 47       myXmlHttpRequest=getXmlHttpObject();
 48        // window.alert(myXmlHttpRequest);
 49       //如果创建成功，则进行post请求
 50       if(myXmlHttpRequest){
 51       //创建url
 52       var url="/ajax/showCities";//post
 53       //携带的参数
 54       var data="province="+$('sheng').value;
 55       //
 56       myXmlHttpRequest.open("post",url,true);
 57       //必填
 58       myXmlHttpRequest.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
 59       //指定回调函数
 60             myXmlHttpRequest.onreadystatechange=chuli;
 61       //发送请求
 62       myXmlHttpRequest.send(data);
 63       
 64       }
 65       
 66       
 67   }
 68   
 69   function chuli(){
 70       if(myXmlHttpRequest.readyState==4){
 71             var mes=    myXmlHttpRequest.responseText;
 72       window.alert(mes);
 73       var mes_obj=eval("("+mes+")");
 74       window.alert(mes_obj);
 75       window.alert(mes_obj.ins[0].city);
 76       // $('myres').value=mes_obj.info;
 77       
 78       
 79       //取出xml格式数据
 80           /* if(myXmlHttpRequest.status==200)
 81           {          
 82               //取出服务器回送的数据
 83               window.alert(myXmlHttpRequest.responseXML);
 84               var cities= (myXmlHttpRequest.responseXML.getElementsByTagName("city"));
 85               //window.alert(cities.length);
 86               //alert(cities[1].lastChild.nodeValue);
 87               for(var i=0;i<cities.length;i++)
 88               {alert(cities[i].childNodes[0].nodeValue);}
 89           } */
 90       
 91       }
 92       
 93   }
 94   
 95   
 96    function $(id)
 97   {
 98   return document.getElementById(id);
 99   }
100   
101   </script>
102   
103   
104     This is my JSP page. <br>
105     
106     <select id="sheng" onchange="getCities();">
107     <option value="">---省---</option>
108     <option value="zhejiang">浙江</option>
109     <option value="jiangsu">江苏</option>
110     </select>
111     
112     <select id="city" onchange="sendRequest();">
113     <option value="">--城市--</option>
114     </select>
115     
116      <select id="country" onchange="sendRequest();">
117     <option value="">--县城--</option>
118     </select>
119     
120   </body>
121 </html>

2.xml格式

servlet代码

 1 package com.hsp.action;
 2 
 3 import java.io.IOException;
 4 import java.io.PrintWriter;
 5 
 6 import javax.json.JsonString;
 7 import javax.servlet.ServletException;
 8 import javax.servlet.annotation.WebServlet;
 9 import javax.servlet.http.HttpServlet;
10 import javax.servlet.http.HttpServletRequest;
11 import javax.servlet.http.HttpServletResponse;
12 
13 /**
14  * Servlet implementation class showCities
15  */
16 @WebServlet("/showCities")
17 public class showCities extends HttpServlet {
18     private static final long serialVersionUID = 1L;
19        
20     /**
21      * @see HttpServlet#HttpServlet()
22      */
23     public showCities() {
24         super();
25         // TODO Auto-generated constructor stub
26     }
27 
28     /**
29      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
30      */
31     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
32         // TODO Auto-generated method stub
33     }
34 
35     /**
36      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
37      */
38     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
39         // TODO Auto-generated method stub
40         response.setContentType("text/xml;charset=utf-8");  
41         response.setHeader("Cache-Control", "no-cache");
42         
43         //接收用户选择的省的名字
44         String shengString=request.getParameter("province");
45         System.out.println(shengString);
46         PrintWriter out=response.getWriter();
47         StringBuilder builder=new StringBuilder();
48       
49 
50         String info="";
51 
52         if ("zhejiang".equals(shengString)) {
53             System.out.println("浙江");
54             info="<province><city>杭州</city><city>温州</city><city>宁波</city></province>";
55         }
56         else if ("jiangsu".equals(shengString)) {
57             System.out.println("江苏");
58 
59             info="<province><city>南京</city><city>徐州</city><city>苏州</city></province>";
60         }
61 //        if ("zhejiang".equals(shengString))
62 //        {
63 //            info= "[{"+'"'+"city"+'"'+":"+'"'+"杭州"+'"'+"},{"+'"'+"city"+'"'+":"+'"'+"温州"+'"'+"}]";
64 //        }
65 //        else if ("jiangsu".equals(shengString)) {
66 //            info= "[{"+'"'+"city"+'"'+":"+'"'+"南京"+'"'+"},{"+'"'+"city"+'"'+":"+'"'+"苏州"+'"'+"}]";
67 //
68 //        }
69 //        System.out.println("{"+'"'+"ins"+'"'+":"+info+"}");
70 //       builder.append("{"+'"'+"ins"+'"'+":"+info+"}");
71         builder.append(info);
72        out.println(builder.toString());
73     }
74 
75 }

jsp代码

  1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
  2 <%
  3 String path = request.getContextPath();
  4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
  5 %>
  6 
  7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
  8 <html>
  9   <head>
 10     <base href="<%=basePath%>">
 11     
 12     <title>My JSP 'Mycity.jsp' starting page</title>
 13     
 14     <meta http-equiv="pragma" content="no-cache">
 15     <meta http-equiv="cache-control" content="no-cache">
 16     <meta http-equiv="expires" content="0">    
 17     <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
 18     <meta http-equiv="description" content="This is my page">
 19     <!--
 20     <link rel="stylesheet" type="text/css" href="styles.css">
 21     -->
 22 
 23   </head>
 24   
 25   <body>
 26   <script type="text/javascript">
 27    //1.创建ajax引擎
 28   function getXmlHttpObject(){
 29   var xmlHttpRequest;
 30   //不同的浏览器获取对象xmlhttprequest对象方法不一样
 31   if(window.ActiveXobject)
 32   {
 33       xmlHttpRequest=new ActiveXobject("Microsoft.XMLHTTP");
 34   }
 35   else
 36   {
 37         xmlHttpRequest=new XMLHttpRequest();
 38   }
 39   return xmlHttpRequest;
 40   }
 41  
 42  //新建myXmlHttpRequest对象
 43  var myXmlHttpRequest="";
 44   
 45   function getCities(){
 46   //创建对象
 47       myXmlHttpRequest=getXmlHttpObject();
 48        // window.alert(myXmlHttpRequest);
 49       //如果创建成功，则进行post请求
 50       if(myXmlHttpRequest){
 51       //创建url
 52       var url="/ajax/showCities";//post
 53       //携带的参数
 54       var data="province="+$('sheng').value;
 55       //
 56       myXmlHttpRequest.open("post",url,true);
 57       //必填
 58       myXmlHttpRequest.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
 59       //指定回调函数
 60             myXmlHttpRequest.onreadystatechange=chuli;
 61       //发送请求
 62       myXmlHttpRequest.send(data);
 63       
 64       }
 65       
 66       
 67   }
 68   
 69   function chuli(){
 70       if(myXmlHttpRequest.readyState==4){
 71            // var mes=    myXmlHttpRequest.responseText;
 72       /* window.alert(mes);
 73       var mes_obj=eval("("+mes+")");
 74       window.alert(mes_obj);
 75       window.alert(mes_obj.ins[0].city); */
 76       // $('myres').value=mes_obj.info;
 77       
 78       
 79    //取出xml格式数据
 80            if(myXmlHttpRequest.status==200)
 81           {          
 82               //取出服务器回送的数据
 83               window.alert(myXmlHttpRequest.responseXML);
 84               var cities= (myXmlHttpRequest.responseXML.getElementsByTagName("city"));
 85               //window.alert(cities.length);
 86               //alert(cities[1].lastChild.nodeValue);
 87               for(var i=0;i<cities.length;i++)
 88               {alert(cities[i].childNodes[0].nodeValue);}
 89           } 
 90       
 91       }
 92       
 93   }
 94   
 95   
 96    function $(id)
 97   {
 98   return document.getElementById(id);
 99   }
100   
101   </script>
102   
103   
104     This is my JSP page. <br>
105     
106     <select id="sheng" onchange="getCities();">
107     <option value="">---省---</option>
108     <option value="zhejiang">浙江</option>
109     <option value="jiangsu">江苏</option>
110     </select>
111     
112     <select id="city" onchange="sendRequest();">
113     <option value="">--城市--</option>
114     </select>
115     
116      <select id="country" onchange="sendRequest();">
117     <option value="">--县城--</option>
118     </select>
119     
120   </body>
121 </html>

3.text格式

servlet 格式

 1 package com.hsp.action;
 2 
 3 import java.io.IOException;
 4 import java.io.PrintWriter;
 5 
 6 import javax.servlet.ServletException;
 7 import javax.servlet.ServletOutputStream;
 8 import javax.servlet.annotation.WebServlet;
 9 import javax.servlet.http.HttpServlet;
10 import javax.servlet.http.HttpServletRequest;
11 import javax.servlet.http.HttpServletResponse;
12 
13 /**
14  * Servlet implementation class registerServlet
15  */
16 @WebServlet("/registerServlet")
17 public class registerServlet extends HttpServlet {
18     private static final long serialVersionUID = 1L;
19        
20     /**
21      * @see HttpServlet#HttpServlet()
22      */
23     public registerServlet() {
24         super();
25         // TODO Auto-generated constructor stub
26     }
27 
28     /**
29      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
30      */
31     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
32         // TODO Auto-generated method stub
33     
34     //接受数据
35         //String username=request.getParameter("username");
36         //System.out.println(username);
37         String infoString="";
38         if ("shunping".equals("")) {
39             infoString="用户名不可用";
40         }
41         else {
42             infoString="用户名可用";
43 
44         }
45         //返回文本数据  
46        // response.setContentType("text/;charset=utf-8");  
47        //返回xml格式文件
48         response.setContentType("text/xml;charset=utf-8");  
49 
50         response.setHeader("Cache-Control", "no-cache");
51         
52         
53         //返回xml 格式数据
54         PrintWriter out=response.getWriter();
55         StringBuilder builder=new StringBuilder();
56        // builder.append("<message>");
57        // builder.append(infoString).append("</message>");
58         
59       //  builder.append( "{"+'"'+"info"+'"'+":"  ).append('"'+infoString+'"'+"}");
60         builder.append(infoString);
61         out.println(builder.toString());
62         
63         //返回text格式数据
64 //        ServletOutputStream outputStream = response.getOutputStream();  
65 //        outputStream.write(infoString.getBytes("utf-8"));  
66 //        //outputStream.write(pwd.getBytes("utf-8"));  
67 //        outputStream.flush();  
68 //        outputStream.close();  
69     }
70 
71     /**
72      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
73      */
74     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
75         // TODO Auto-generated method stub
76         doGet(request, response);
77     }
78 
79 }

jsp格式

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'index.jsp' starting page</title>
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->
  </head>
  
  <body>
  <script type="text/javascript">
  
  //创建ajax引擎
  function getXmlHttpObject(){
  var xmlHttpRequest;
  //不同的浏览器获取对象xmlhttprequest对象方法不一样
  if(window.ActiveXobject)
  {
      xmlHttpRequest=new ActiveXobject("Microsoft.XMLHTTP");
  }
  else
  {
        xmlHttpRequest=new XMLHttpRequest();
  }
  return xmlHttpRequest;
  }
  
  
  var    myXmlHttpRequest=null;
  //验证用户名是否存在
  function checkName()
  {
  
     myXmlHttpRequest=getXmlHttpObject();
      
  //    window.alert(myXmlHttpRequest);
 
 if(myXmlHttpRequest ){
  //    window.alert("创建成功");
      //通过myXmlHttpRequest对象发送请求到服务器的某个页面
      //1.第一个参数表示请求的方式，"get"/"post"
      //2.第二个参数指定url,对哪个页面发出ajax请求（本质仍然是http请求）
      //3.第三个参数 true表示使用异步机制，如果false，表示不使用异步
       var url="/ajax/registerServlet?mytime="+new Date()+"&username="+$("username").value
      //打开请求
      myXmlHttpRequest.open("post",url,true);
      //window.alert(url);
      //指定回调函数,chuli  是函数名
      myXmlHttpRequest.onreadystatechange=chuli;
      //真的发送函数,如果是get请求，则填入null即可
      //如果是post请求，则填入实际的数据
      myXmlHttpRequest.send(null); 
      
      
      }
 
      
  }
  
  //回调函数
   function chuli(){
  //window.alert("处理函数被调用"+myXmlHttpRequest.readyState);
  //取出从serlet返回的数据
   if(myXmlHttpRequest.readyState==4)
      {
      //取出值，文本格式
     //window.alert("服务器返回"+myXmlHttpRequest.responseText)
 //
 //window.alert( "xml:"+myXmlHttpRequest.responseXML);
  //获取message节点
 // var mes=myXmlHttpRequest.responseXML.getElementsByTagName("message");
  //window.alert(mes.length);
  //取出message节点
  //es[0]-->表示取出第一个message节点
  //childNodes[0]表示message节点的第一个子节点
 // var mes_val=mes[0].childNodes[0].nodeValue;
  //window.alert(mes_val);
 // ${'myres'}.value= mes_val;
      //$('myres').value=myXmlHttpRequest.responseText;
  /* var mes=    myXmlHttpRequest.responseText;
      window.alert(mes);
      var mes_obj=eval("("+mes+")");
      //window.alert(mes_obj.info);
       $('myres').value=mes_obj.info;
       */
        var mes=    myXmlHttpRequest.responseText;
       
             $('myres').value=mes;
      
      } 
  }
    
  function $(id)
  {
  return document.getElementById(id);
  }
   
  
  
  
 
   
  
  
  
  
  
  
  
  
  
 
  </script>
  
  
    This is my JSP page. <br>
    <form action="???" method="post">
    
    用户名：<input type="text"name="username1" onkeyup="checkName();" id="username">
    <input type="button" onclick="checkName();" value="验证用户名">
  <input style="border- 0;color: red" type="text" id="myres"><br>
    用户密码：<input type="password" name="password"><br>
    电子邮件:<input type="text" name="email"><br>
    <input type="submit" value="用户注册"> 
    </form>
    
    
    
  </body>
</html>

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原文地址：https://www.cnblogs.com/albertfg/p/8031599.html