jsp页面--secondajax.jsp
1 <%@ page language="java" contentType="text/html; charset=UTF-8" 2 pageEncoding="UTF-8"%> 3 <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> 4 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 5 <html> 6 <head> 7 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 8 <title>Insert title here</title> 9 </head> 10 <script type="text/javascript"> 11 function createXMLHttpRequest() { 12 try { 13 return new XMLHttpRequest(); 14 } catch (e) { 15 try { 16 return new ActiveXObject("Msxml2.XMLHTTP"); 17 } catch (e) { 18 try { 19 return new ActiveXObject("Microsoft.XMLHTTP"); 20 } catch (e) { 21 alert("浏览器不兼容"); 22 } 23 } 24 } 25 }; 26 27 window.onload = function() { 28 var btn = document.getElementById("btn"); 29 30 btn.onclick = function(){ 31 32 //获取XMLHttpRequest对象 33 var xmlHttp = createXMLHttpRequest(); 34 35 //连接服务器 36 xmlHttp.open("POST","<c:url value='/SecondServlet'/>",true); 37 38 //设置POST请求的请求头 39 xmlHttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded"); 40 41 //发送请求体内容 42 xmlHttp.send("username=张三&password=123"); 43 44 //ajax接收服务器数据 45 xmlHttp.onreadystatechange = function() { 46 if (xmlHttp.readyState == 4 && xmlHttp.status == 200) { 47 48 var text = xmlHttp.responseText;//接收服务器响应数据 49 var h1 = document.getElementById("h1"); 50 h1.innerHTML = text; 51 } 52 }; 53 }; 54 }; 55 </script> 56 57 <body> 58 <button id="btn">获取post请求的servlet响应内容</button> 59 <h1 id="h1"></h1> 60 </body> 61 </html>
Servlet-->SecondServlet.java
1 package ajax; 2 3 import java.io.IOException; 4 import java.io.PrintWriter; 5 6 import javax.servlet.ServletException; 7 import javax.servlet.http.HttpServlet; 8 import javax.servlet.http.HttpServletRequest; 9 import javax.servlet.http.HttpServletResponse; 10 11 public class SecondServlet extends HttpServlet { 12 13 private static final long serialVersionUID = -8677043877281884063L; 14 15 public void doPost(HttpServletRequest request, HttpServletResponse response) 16 throws ServletException, IOException { 17 18 //POST请求需要设置编码 19 request.setCharacterEncoding("utf-8");//设置处理请求的编码 20 response.setContentType("text/html;charset=utf-8");//设置响应的编码--给浏览器的 21 22 String username = request.getParameter("username"); 23 String password = request.getParameter("password"); 24 response.getWriter().print(username+" 您好! 您的登录密码是:"+password); 25 26 } 27 28 }
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