Ajax验证用户名是否存在模板

最新推荐文章于 2025-08-04 10:37:14 发布

原创最新推荐文章于 2025-08-04 10:37:14 发布 · 223 阅读

CC 4.0 BY-SA版权

Jsp 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 'Demo1.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">

<script src="js/jquery-3.0.0.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript">
$(function(){
$('#in').click(function(){
$.ajax({
type:"post",
url:"login",
async:true,
data:{
name:$('#userNo').val(),
},
success:function(data){
if (data=='0') {
$('#show').html('<font color="red">用户名已存在</font>');
} else{
$('#show').html('<font color="green">用户名可用</font>');
}
}
});
})

})
</script>
</head>

<body>
用户名:<input id="userNo" type="text" />
<input id="in" type="button" value="登录" />
<div id="show"></div>
</body>
</html>

Servlet 页面

package com.jereh.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class LoginServlet extends HttpServlet {

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
List<String> names = Arrays.asList("aaa","bbb","ccc");
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String name = request.getParameter("name");
if (names.contains(name)) {
out.print("0");
} else {
out.print("1");
}

out.flush();
out.close();
}

}