JSP + Servlet 实现 AJAX（纯JS版）

==============java 文件，包名org.rain.servlet

package org.rain.servlet;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.List;

import javax.servlet.ServletConfig;

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 org.rain.bean.PageSystemBean;

@WebServlet("/mulAJAXPageSystem")

public class MulAJAXPage extends HttpServlet {

protected void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

response.setContentType("text/html;charset=UTF-8");

try (PrintWriter out = response.getWriter()) {

out.println("<b> SmallRain AjAX 请求返回数据 </b");

}

}

protected void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

doGet(request, response);

}

}

======================JSP文件

<%@ page language="java" contentType="text/html; charset=UTF-8"

pageEncoding="UTF-8"%>

<html>

<head>

<meta charset="UTF-8">

<title>晓雨 JSP + Servlet 实现 AJAX</title>

<script>

function smallRainShowData() {

var smallrainAjAXRequest = new XMLHttpRequest();

smallrainAjAXRequest.open('GET', 'mulAJAXPageSystem', true);

smallrainAjAXRequest.send();

smallrainAjAXRequest.onreadystatechange = function() {

if (smallrainAjAXRequest.readyState === 4

&& smallrainAjAXRequest.status === 200) {

var showData = smallrainAjAXRequest.responseText;

document.getElementById('smallrainContent').innerHTML = showData;

}

}

}

</script>

</head>

<body>

<h1>晓雨 JSP + Servlet 实现 AJAX</h1>

<button οnclick="smallRainShowData()">AJAX 请求</button>

<div id="smallrainContent"></div>

</body>

</html>