Jquery实现ajax：
$.ajax({
type //数据的提交方式：get和post
url //数据的提交路径
async //是否支持异步刷新，默认是true
data //需要提交的数据
datatype //服务器返回数据的类型，例如xml,String,Json等
success //请求成功后的回调函数
error //请求失败后的回调函数});
}
)
json对服务器返回结果是集合的处理
<script>
$(function(){
$("#btn").click(function(){ 单击按钮时
$.ajax({
type:"get", 请求方式
url:"ShowServlet", 跳转路径
async:true, 异步请求
success:function(data){成功处理
var json = eval('('+data+')'); 将JSON的字符串解析成JSON数据格式
var table="<table>";
for(var i in json){
table+="<tr><td>"+json[0].id+"</td><td>"+json[i].name+"</td><td>"+json[i].birthday+"</td><td>"+json[i].regTime+"</td></tr>";
$("#show").html(table);显示在页面
}
table+="</table>";
},
代码实现：
userList.jsp
<%--
Description:ajax 返回集合
User: jiatp
Date: 2019/5/22
Time: 21:45
--%>
<%@ 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">
<title>Insert title here</title>
</head>
<script type="text/javascript" src="js/jquery.js"></script>
<script type="text/javascript">
//初始化
$(function () {
$("#btn").click(function () {
$.ajax({
type:"post",
url:"showAllUserList",
data:{},
datatype:"json",
success:function (data) {
//转换为javascript对象
var user = eval('('+data+')');
var str = "<table>";
var strcontent = "";
for(var i=0;i<user.length;i++){
strcontent+="<tr><td>"+user[i].id+"</td><td>"+user[i].name+"</td><td>"+user[i].address+"</td></tr>"
}
str+=strcontent+"</table>";
$("#content").html(str);
},error:function () {
alert("error!");
}
})
})
})
</script>
<body>
<input type="button" id="btn" value="显示集合">
<div id="content"></div>
</body>
</html>showAllUserList.java
package com.chinasofti.servlet;
import com.chinasofti.entity.User;
import net.sf.json.JSONArray;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
/**
* Description:ajax返回一个集合对象
* USER:jiatp
* Date:2019/5/22 22:16
* */
@WebServlet("/showAllUserList")
public class showAllUserList extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
request.setCharacterEncoding("utf-8");
List<User> userList = new ArrayList();
User user1 = new User();
user1.setName("张三");
user1.setAddress("北京");
user1.setId(1);
User user2 = new User();
user2.setName("李四");
user2.setAddress("上海");
user2.setId(2);
//添加到集合
userList.add(user1);
userList.add(user2);
PrintWriter out = response.getWriter();
//将user对象转换成json格式
JSONArray json = JSONArray.fromObject(userList);
System.out.println(json);
out.print(json);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}
注：var json = eval('('+data+')'); 将JSON的字符串解析成JSON数据格式