1.后台返回text类型的数据
<%@ 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">
-->
<script type="text/javascript" src="js/jquery-1.8.3.min.js"></script>
<script type="text/javascript">
$(function(){
$("#btn").click(function(){
//获取用户的输入
var name= $("#name").val();
$.ajax({
url:"AjaxServlet", /*对应的是web.xml文件中url 也是我们的请求路径 */
type:"post", /* 请求的方式 */
data:"name="+name, /* 请求中携带的数据 */
dataType:"text", /* 后台返回的数据类型 */
beforeSend:function(){
alert("请求正在处理。。。。。。");
},
success:function(data){
alert(data); }
});
});
});
</script> </head> <body> 用户名：<input type="text" id="name">
<input type="button" id="btn" value="请求ajax"> </body>
</html>
前台jsp页面
public class AjaxServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("进入了ajax..........");
response.setHeader("Content-type", "text/html;charset=utf-8");
// 01.获取ajax请求过来的name值
String name = request.getParameter("name");
response.getWriter().print(name);
}
}创建对应的servlet
2.返回单个对象
public class Student {
private String name;
private String pwd;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
public Student(String name, String pwd) {
super();
this.name = name;
this.pwd = pwd;
}
public Student() {
super();
}
@Override
public String toString() {
return "Student [name=" + name + ", pwd=" + pwd + "]";
}
}Student实体类
前台jsp页面
<%@ 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">
-->
<script type="text/javascript" src="js/jquery-1.8.3.min.js"></script>
<script type="text/javascript">
$(function(){
$("#btn").click(function(){
//获取用户的输入
var name= $("#name").val();
$.ajax({
url:"AjaxServlet", /*对应的是web.xml文件中url 也是我们的请求路径 */
type:"post", /* 请求的方式 */
data:"name="+name, /* 请求中携带的数据 */
dataType:"json", /* 后台返回的数据类型 */
beforeSend:function(){
alert("请求正在处理。。。。。。");
},
success:function(data){
/* 返回集合 */ //返回单个对象 alert(data);
$("#myDiv").append("姓名："+data.name);
$("#myDiv").append("密码："+data.pwd);
}
});
});
});
</script> </head> <body> 用户名：<input type="text" id="name">
<input type="button" id="btn" value="请求ajax">
<div id="myDiv"></div> </body>
</html>
public class AjaxServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("进入了ajax..........");
response.setHeader("Content-type", "text/html;charset=utf-8");
// 创建一个Student对象 返回给前台
Student student = new Student("admin1", "123456");
// 需要把student对象转换成json格式
System.out.println("转换前==》" + student);
Gson gson = new Gson();
// json 就是转换之后的 student对象 {"name":"admin","pwd":"123456"}
String json = gson.toJson(student);
System.out.println("转换后==" + json);
response.getWriter().print(json);
}
}对应的servlet
3.返回对象的集合
<%@ 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">
-->
<script type="text/javascript" src="js/jquery-1.8.3.min.js"></script>
<script type="text/javascript">
$(function(){
$("#btn").click(function(){
//获取用户的输入
var name= $("#name").val();
$.ajax({
url:"AjaxServlet", /*对应的是web.xml文件中url 也是我们的请求路径 */
type:"post", /* 请求的方式 */
data:"name="+name, /* 请求中携带的数据 */
dataType:"json", /* 后台返回的数据类型 */
beforeSend:function(){
alert("请求正在处理。。。。。。");
},
success:function(data){
/* 返回集合 */
$("#myDiv").append("<span>姓名</span> ");
$("#myDiv").append("<span>密码</span></br>");
//遍历传递过来的json数组
$(data).each(function(i){
$("#myDiv").append("<span>"+data[i].name+"</span> ");
$("#myDiv").append("<span>"+data[i].pwd+"</span></br>");
}) }
});
});
});
</script> </head> <body> 用户名：<input type="text" id="name">
<input type="button" id="btn" value="请求ajax">
<div id="myDiv"></div> </body>
</html>
前台jsp页面
public class AjaxServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("进入了ajax..........");
response.setHeader("Content-type", "text/html;charset=utf-8");
Student student1 = new Student("admin1", "123456");
Student student2 = new Student("admin2", "123456");
Student student3 = new Student("admin3", "123456");
Student student4 = new Student("admin4", "123456");
ArrayList<Student> list = new ArrayList<Student>();
list.add(student1);
list.add(student2);
list.add(student3);
list.add(student4);
System.out.println("转换前==》" + list);
Gson gson = new Gson();
String json = gson.toJson(list);
System.out.println(json);
response.getWriter().print(json);
}
}对应的servlet