<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>ajax demo</title>
<script type="text/javascript">
var xmlHttpRequest = null;
function ajaxSubmit(){
// window.alert(window.ActiveXObject);
if(window.ActiveXObject){ //是IE浏览器
xmlHttpRequest = new ActiveXObject("Microsoft.XMLHTTP");
}else if(window.XMLHttpRequest){ //除IE外的其他浏览器
xmlHttpRequest = new XMLHttpRequest();
}
/*
使用Ajax准备向服务器端发送一个请求
*/
if(null != xmlHttpRequest){ //使用GET方式， //异步
var num1 = document.getElementById("num1").value;
var num2 = document.getElementById("num2").value;
// xmlHttpRequest.open("GET","AjaxServlet?num1=" + num1 + "&num2=" + num2,"true");
xmlHttpRequest.onreadystatechange = ajaxCallBack; //注册一个回调函数
//向服务器端发送数据
// xmlHttpRequest.send(null); //get方式设置为null
//post方式
xmlHttpRequest.open("POST","AjaxServlet","true");
//使用post方式提交数据，必须加上下面这行代码
xmlHttpRequest.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
xmlHttpRequest.send("num1=" + num1 + "&num2=" + num2);
}
}
function ajaxCallBack(){
if(xmlHttpRequest.readyState == 4){
if(xmlHttpRequest.status == 200){
var responseText = xmlHttpRequest.responseText;
document.getElementById("content").innerHTML = responseText;
}
}
}
</script>
</head>
<body>
<input type="text" name="num1" id="num1"/> <br/>
<input type="text" name="num2" id="num2"/> <br/>
<input type="button" value="从服务区端获取数据" onclick="ajaxSubmit();"/>
<div id="content"></div>
</body>
</html>
后台处理代码
package com.ajax.test;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class AjaxServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public void doGet(HttpServletRequest request,HttpServletResponse response)
throws ServletException,IOException {
response.setContentType("text/html");
String num1 = request.getParameter("num1");
String num2 = request.getParameter("num2");
int num3 = Integer.valueOf(num1) + Integer.valueOf(num2);
PrintWriter out = response.getWriter();
System.out.println("AjaxServlet.doGet()");
out.println(num3);
}
public void doPost(HttpServletRequest request,IOException {
System.out.println("AjaxServlet.doPost()");
this.doGet(request,response);
}
}
原文链接：https://www.f2er.com/ajax/164964.html
