Ajax小案例：验证表单中用户名是否可用
2017-04-21 本文已影响106人
Mr_欢先生
需求：输入用户名判断是否存在此用户
创建表单index.jsp
<%--
Created by IntelliJ IDEA.
User: pc
Date: 17-4-21
Time: 下午5:15
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>注册信息</title>
<script type='text/javascript' src='../js/jquery.min.js' charset='utf-8'></script>
<style>
.top {
margin-left: 800px;
margin-top: 200px;
}
</style>
<script type="text/javascript">
$(function () {
$(":input[name='username']").change(function () {
var name = $(this).val();
name = $.trim(name);//取出前后空格
if (name != "") {
var url = "/Login_AServlet";
var args = {"username": name, "time": new Date()};
$.get(url, args, function (data) {
$(".message").html(data)
});
}
});
});
</script>
</head>
<body>
<div class="top">
<h1>信息注册</h1>
<form action="#" method="post">
用户名：<input type="text" name="username"><span class="message"> </span><br>
邮 箱：<input type="text" name="emile"><br>
性 别：<input type="radio" name="sex" value="男生" checked="checked">男生
<input type="radio" name="sex" value="女生">女生<br>
<input type="submit" value="登 录">
</form>
</div>
</body>
</html>
Login_AServlet.java
<%--
Created by IntelliJ IDEA.
User: pc
Date: 17-4-21
Time: 下午12:10
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<script type='text/javascript' src='./js/jquery.min.js' charset='utf-8'></script>
<title>Title</title>
<script type="text/javascript">
$(function () {
$("a").click(function () {
var url = this.href;
var time = {"time": new Date()}
$.post(url, time, function (data) {
var name = $(data).find("name").text();
var age = $(data).find("age").text();
var email = $(data).find("email").text();
$(".html_").html("");
$(".html_").append("<h2>姓名：" + name + "性别：" + age + "邮箱：" + email);
});
return false;
});
});
</script>
<title>Title</title>
</head>
<body>
<h1>学生信息：</h1>
<ul>
<li><a href="./xml_ajax/huan.xml">马小欢</a></li>
<li><a href="./xml_ajax/yun.xml">赵云</a></li>
<li><a href="./xml_ajax/ming.xml">小明</a></li>
</ul>
<h1 class="html_"></h1>
</body>
</html>
用户名存在
用户不存在
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