创建的java web项目
前端页面
<%@ 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> function TestAjax(){ var xmlHttp; if (window.XMLHttpRequest) { xmlHttp = new XMLHttpRequest(); } else { xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); } xmlHttp.onreadystatechange = function(){ if (xmlHttp.readyState==4 && xmlHttp.status==200) { document.getElementById("sp").innerHTML = xmlHttp.responseText; } } xmlHttp.open("GET", "TestAjax?name=Ouyang", true); xmlHttp.send(); } </script> </head> <body> <button onclick="TestAjax()">利用Ajax获取数据</button> <br> <span id = "sp"></span> </body> </html>
后台程序(需配置web.xml，不赘述)
package com.ajax; import java.io.IOException; import java.io.PrintWriter; 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 javax.swing.RepaintManager; /** * Servlet implementation class TestAjax */ @WebServlet("/TestAjax") public class TestAjax extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public TestAjax() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub //response.getWriter().append("Served at: ").append(request.getContextPath()); response.setCharacterEncoding("UTF-8"); PrintWriter out = response.getWriter(); out.println("Hello " + request.getParameter("name")); out.flush(); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doGet(request, response); } }