![](/image//upload/attachment/130823/26da8284-52d1-313f-a34d-9b2cc4e07fff.jpg)
1.伺服器端的Servlet的源代碼:
AJAXServer.java源代碼
- package test;
- import java.io.*;
- import javax.servlet.*;
- import javax.servlet.http.*;
- public class AJAXServer extends HttpServlet {
- public void doGet(HttpServletRequest request, HttpServletResponse response)
- throws ServletException, IOException {
- this .doPost(request, response);
- }
- public void doPost(HttpServletRequest request, HttpServletResponse response)
- throws ServletException, IOException {
- response.setContentType("text/html;charset=UTF-8" );
- PrintWriter out = response.getWriter();
- String old = request.getParameter("userName" );
- if (old == null || old.length() == 0 ) {
- out.println("使用者名不能為空" );
- } else {
- if (old.equals( "admin" )) {
- out.println("使用者名 [" + old + "] 已經存在,請使用其他使用者名" );
- } else {
- out.println("使用者名 [" + old + "] 尚未存在,可以使用該使用者名注冊" );
- }
- }
- }
- }
2.web.xml中關于AJAXServer的配置。
Xml代碼
- < servlet >
- < servlet-name >AJAXServer </ servlet-name >
- < servlet-class > test.AJAXServer </ servlet-class >
- </ servlet >
- < servlet-mapping >
- < servlet-name >AJAXServer </ servlet-name >
- < url-pattern > /AJAXServer </ url-pattern >
- </ servlet-mapping >
3.用戶端html代碼的實作。
ajax01.html源代碼:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>ajax01.html</title>
<script type="text/javascript" src="web/jquarylib/jquery.js"></script>
<script type="text/javascript" src="web/jquarylib/verify.js"></script>
</head>
<body>
<input type = "text" id ="username"/>
<input type = "button" value="11" οnclick="verify();"/>
<div id="result"></div>
</body>
</html>
4.用戶端javascript代碼的實作。
verify.js源代碼:
function verify(){
var jqueryObj = $("#username");
var username = jqueryObj.val();
$.get("AJAXServer?username=" + username,null,callback);
}
function callback(data){
$("#result").html(data);
}