利用servlet进行简单的登陆验证

来源：互联网发布：广州雷霆网络刀塔世纪编辑：程序博客网时间：2024/06/05 17:52

新建一个Web工程P21_Refresh,该工程包含一个java文件和一个jsp文件,一张资源图片enter.gif,各文件内容如下:

1.LoginAction.java,主用是实现控制器功能.

package classmate;

import java.io.IOException;

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

public class LoginAction extends HttpServlet {

protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
  String uname = req.getParameter("uname");
  String psw = req.getParameter("psw");

  String target = "";

  HttpSession session = req.getSession();

  if(uname.equals("jenny") && psw.equals("hi")){
   session.setAttribute("result","ok");
   target = "/P21_Refresh/login.jsp";
  }else{
   session.setAttribute("result","wrong");
   target = "/P21_Refresh/login.jsp";
  }

  resp.sendRedirect(target);
}

}
2.login.jsp,主要是实现登陆视图功能:

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%
String result = (String)session.getAttribute("result");
  if(result != null && result != ""){
  if(result.equals("ok")){
   out.println("<script>window.alert('热烈的欢迎您!')</script>");
  }else{
   out.println("<script>window.alert('对不起,登录失败！')</script>");
  }
  session.invalidate();
}
%>
<body vLink="#006666" link="#003366" bgColor="#E0F0F8">
<img height="33" src="enter.gif" width="148">
<form action="login" method="post">
用户名： <input size="15" name="uname"><p>
密  码： <input type="password" size="15" name="psw"><p>
<input type="submit" value="登录">
</form>

3.配置文件web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<servlet>
<servlet-name>ms1</servlet-name>
<servlet-class>classmate.LoginAction</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>ms1</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>

<welcome-file-list>
<welcome-file>login.jsp</welcome-file>
</welcome-file-list>
</web-app>