ページ：スクリプト内のコード
<script type="text/javascript">
window.onload = function(){
var nameV= document.getElementsByName("pass")[0];
nameV.onblur = function(){
var name = this.value;
var re = new XMLHttpRequest();
re.open("post", "checkpass?pass="+name);
re.onreadystatechange = function(){
if(re.readyState == 4)
{
if(re.status==200)
{
if(re.responseText==0)
{
tsy.innerHTML= "可以登陆！";
tsy.style.color="red";
}
else if (re.responseText == true){
tsy.innerHTML= "密码为空,请输入！";
tsy.style.color="red";
}
else {
alert("Mima不对，请重新输入！")
}
}
}
}
re.send(null);
}
}
</script>
```java
<body>
<form action="LoginServlet" method="post">
<div style="margin-top: 372px;margin-left: 725px">
<input type="text" name="Id" placeholder="请输入学号" autocomplete="off"><br><br><br>
<input type="password" name="pass" placeholder="请输入身份证号">
<br><br>
<input type="submit" style="background-image: url(Images/login.gif);width: 95px;height: 34px;border: none" value=""></div>
</form></body>
selvert处理页面
```javascript
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String user = request.getParameter("Id");
String pass = request.getParameter("pass");
//连接池连接数据库
QueryRunner qr = new QueryRunner(DruidUtils.getDataSource());
String sql = "select * from userList where userID = ? and IDcard = ?";
ListBean listBean = null;
try {
listBean = qr.query(sql,new BeanHandler<ListBean>(ListBean.class),user,pass);
if(listBean != null){
HttpSession session = request.getSession();
session.setAttribute("user",listBean);
//登录成功
request.getRequestDispatcher("TZ.jsp").forward(request,response);
}else{
//登录失败
request.getRequestDispatcher("shibai.jsp").forward(request,response);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request,response);
}
}
