1 <%@ page language="java" contentType="text/html; charset=UTF-8"
2 pageEncoding="UTF-8"%>
3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
4 <html>
5 <head>
6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
7 <title>Insert title here</title>
8 </head>
9 <script type="text/javascript">
10 var req;
11 function check()
12 {
13 var url ="CheckUser?uname="+ document.getElementById("uname").value;
14 if (window.XMLHttpRequest)
15 {
16 req = new XMLHttpRequest();
17 }
18 else if (window.ActiveXObject){
19 req = new ActiveXObject("Microsoft.XMLHTTP");
20 }
21 req.open("GET",url, true);
22 req.onreadystatechange = show;
23 req.send(null);
24 alert("hhhh");
25 }
26 function show(){
27 if (req.readyState == 4) {
28 if (req.status == 200) {
29 document.getElementById("info").innerHTML=req.responseText;
30 }
31 }
32 }
33 </script>
34 <body>
35 <table>
36 <tr><td>用户名</td><td><input type="text" id="uname" ></td></tr>
37 <tr><td><input type="button" onClick="check()" value="检测用户"></td><td><div id="info"></div> </td></tr>
38 </table>
39 </body>
40 </html>
1 package javastudy;
2
3 import java.io.IOException;
4 import javax.servlet.ServletException;
5 import javax.servlet.annotation.WebServlet;
6 import javax.servlet.http.HttpServlet;
7 import javax.servlet.http.HttpServletRequest;
8 import javax.servlet.http.HttpServletResponse;
9
10 /**
11 * Servlet implementation class CheckUser
12 */
13 @WebServlet("/CheckUser")
14 public class CheckUser extends HttpServlet {
15 private static final long serialVersionUID = 1L;
16
17 /**
18 * @see HttpServlet#HttpServlet()
19 */
20 public CheckUser() {
21 super();
22 // TODO Auto-generated constructor stub
23 }
24
25 /**
26 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
27 */
28 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
29 // TODO Auto-generated method stub
30 String uname=request.getParameter("uname");
31 String[] names={"zhang","yang","wang"};
32 boolean flag=true;
33 for(int i =0;i<names.length;i++)
34 {
35 if(names[i].equals(uname))
36 {
37 flag=false;
38 break;
39 }
40
41 }
42 response.setCharacterEncoding("utf-8");
43 if(flag==false)
44 {
45 response.getWriter().println("该用户名已注册!!!");
46 }
47 else
48 {
49 response.getWriter().println("注册成功！！！");
50 }
51 // response.getWriter().append("Served at: ").append(request.getContextPath());
52 }
53
54 /**
55 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
56 */
57 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
58 // TODO Auto-generated method stub
59 doGet(request, response);
60 }
61
62 }
