大数据必学Java基础（一百一十二）：开发案例之登录验证
原创大数据必学Java基础（一百一十二）：开发案例之登录验证
原创
Lansonli
发布于 2022-12-23 11:51:57
发布于 2022-12-23 11:51:57
开发案例之登录验证
需求：通过过滤器控制,只有登录过之后可以反复进入welcome.jsp欢迎页,如果没有登录,提示用户进入登录页进行登录操作。
一、准备实体类
User类：
package com.lanson.pojo;
import java.io.Serializable;
/**
* @Author: Lansonli
* @Description: MircoMessage:Mark_7001
*/
public class User implements Serializable {
private String username;
private String password;
@Override
public String toString() {
return "User{" +
"username='" + username + '\'' +
", password='" + password + '\'' +
'}';
}
public User() {
}
public User(String username, String password) {
this.username = username;
this.password = password;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}二、准备一些页面和静态资源
login.jsp：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Title%sSourceCode%lt;/title>
</head>
<body>
<img src="static/img/logo.png">
please login ... ... <br/>
<form action="loginController.do" method="post">
用户名:<input type="text" name="user"> <br/>
密码:<input type="password" name="pwd"><br/>
<input type="submit" value="提交">
</form>
</body>
</html>welcome.jsp：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<img src="static/img/logo.png">
欢迎${user.username}登陆!!!
</body>
</html>aaa.jsp：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
this is page aaa
</body>
</html>三、准备Controller代码
package com.lanson.controller;
import com.lanson.pojo.User;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
/**
* @Author: Lansonli
* @Description: MircoMessage:Mark_7001
*/
@WebServlet(urlPatterns = "/loginController.do")
public class LoginController extends HttpServlet {
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
// 获取用户名和密码
String username = req.getParameter("user");
String password = req.getParameter("pwd");
System.out.println(username);
System.out.println(password);
// 链接数据库校验登录
// 登录成功,将用户信息放入Session域
User user =new User(username,password);
req.getSession().setAttribute("user", user);
// 跳转到欢迎页
resp.sendRedirect("welcome.jsp");
}
}四、准备登录控制过滤器
package com.lanson.filter;
import com.lanson.pojo.User;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
/**
* @Author: Lansonli
* @Description: MircoMessage:Mark_7001
*/
@WebFilter(urlPatterns = "/*")// 任何资源都要进行过滤,
public class Filter1_LoginFilter implements Filter {
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
HttpServletRequest req=(HttpServletRequest)servletRequest;
HttpServletResponse resp=(HttpServletResponse) servletResponse;
//无论是否登录过,都要放行的资源 登录页 登录校验Controller 和一些静态资源
String requestURI = req.getRequestURI();
System.out.println(requestURI);
if(requestURI.contains("login.jsp")|| requestURI.contains("loginController.do")|| requestURI.contains("/static/")){
// 直接放行
filterChain.doFilter(req,resp);
// 后续代码不再执行
return;
}
// 需要登录之后才能访问的资源,如果没登录,重定向到login.jsp上,提示用户进行登录
HttpSession session = req.getSession();
Object user = session.getAttribute("user");
if(null != user){// 如果登录过 放行
filterChain.doFilter(req,resp);
}else{// 没有登录过,跳转至登录页
resp.sendRedirect("login.jsp");
}
}
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void destroy() {
}
}原创声明：本文系作者授权腾讯云开发者社区发表，未经许可，不得转载。
如有侵权，请联系 cloudcommunity@tencent.com 删除。
原创声明：本文系作者授权腾讯云开发者社区发表，未经许可，不得转载。
如有侵权，请联系 cloudcommunity@tencent.com 删除。
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