pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Ajax验证</title>
<script type="text/javascript" src="jquery.min.js"></script>
<script type="text/javascript">
/* var req;
function checkit() {
//把用户名传到服务器，看看该用户是否已经被注册了
//判断浏览器类型，生成一个req对象，用它和服务器联系
if (window.XMLHttpRequest) {
req = new XMLHttpRequest();
} else if (window.ActiveXObject) {
req = new ActiveXObject("Microsoft.XMLHTTP");
}
var url="CheckUser?uname="+document.getElementById("uname").value;
req.open("GET",url, true);
req.onreadystatechange = show;//访问结束拿到结果交给社处理？
req.send(null);
}
function show()
{
if (req.readyState == 4) {
if (req.status == 200) {
//显示
document.getElementById("info").innerHTML=req.responseText;
}
}
} */
$(function(){
$(":button").click(function(){
/* obj=$.ajax({url:"CheckUser?uname="+$("#uname").val(),async:false});
// $("#info").html(obj.responseText);
$("#info").load("CheckUser?uname="+$("#uname").val() ); */
$.get("CheckUser?uname="+$("#uname").val(),function(data,status){
$("#info").html(data);
});
});
});
</script>
</head>
<body>
<table>
<tr>
<td>用户名</td>
</tr>
<tr>
<td><input type="text" id="uname"></td>
</tr>
<tr>
<td><input type="button" value="检测用户" onClick="checkit()"></td>
</tr>
<tr>
<td><div id="info"></div></td>
</tr>
</table>
</body>
</html>
package javastudy;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class CheckUser
*/
@WebServlet("/CheckUser")
public class CheckUser extends HttpServlet {
private static final long serialVersionUID = 1L;
public CheckUser() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setCharacterEncoding("UTF-8");
String uname=request.getParameter("uname");
String[] names= {"zhang","wang","zhou","shai"};
boolean flag=false;
for(int i=0;i<names.length;i++)
{
if(names[i].equals(uname))
{
flag=true;
break;
}
}
if(flag) {
response.getWriter().println("该用户名已注册！");
}else {
response.getWriter().println("恭喜，该用户名尚未注册！");
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}