Ajax

简介

  • Ajax: Asynchronous JavaScript and XML(异步js和xml)
  • 是一种无需重新加载整个网页的情况下,能更新部分网页的技术
  • 是web应用程序的技术
  • 实例: google或者baidu的搜索框

示例

login.jsp

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<%--
Created by IntelliJ IDEA.
User: Yiqing
Date: 2020-11-16
Time: 10:47 a.m.
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
<script src="${pageContext.request.contextPath}/statics/js/jquery-3.5.1.js"></script>

<script>
function a1() {
$.post({
url:"${pageContext.request.contextPath}/a3",
data: {"name":$("#name").val()},
success:function(data){
if(data.toString() === 'ok'){
$("#userInfo").css("color","green");
}else{
$("#userInfo").css("color","red");
}
$("#userInfo").html(data)
}
})
}
function a2() {
$.post({
url:"${pageContext.request.contextPath}/a3",
data: {"pwd":$("#pwd").val()},
success:function(data){
if(data.toString() === 'ok'){
$("#pwdInfo").css("color","green");
}else{
$("#pwdInfo").css("color","red");
}
$("#pwdInfo").html(data)
}
})
}
</script>
</head>
<body>

<p>
用户名: <input type="text" id="name" onblur="a1()">
<span id="userInfo"></span>
</p>
<p>
密码: <input type="text" id="pwd" onblur="a2()">
<span id="pwdInfo"></span>
</p>

</body>
</html>

AjaxController

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@RequestMapping("/a3")
public String a3(String name,String pwd){
String msg = "";
if(name!=null){
if("admin".equals(name)){
msg = "ok";
}else{
msg = "用户名错误";
}
}
if(pwd!=null){
if("123456".equals(pwd)){
msg = "ok";
}else{
msg = "密码有误";
}
}
return msg;
}