1. 设置登录界面（JSP文件）
<%--
Created by IntelliJ IDEA.
User: Administrator
Date: 2020/9/12
Time: 10:16
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<form action="${ pageContext.request.contextPath}/login" method="post">
<input type="text" name="user">
<br>
<input type="password" name="pwd">
<br>
<input type="checkbox" name="check">
记住密码
<input type="submit" value="登录">
</form>
</body>
</html>
<%@ page import="com.fy.domain.User" %><%--
Created by IntelliJ IDEA.
User: Administrator
Date: 2020/9/12
Time: 11:16
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
欢迎您，<span><%= ((User)session.getAttribute("user")).getUsername() %></span>
</body>
</html>
2. 连接导数据库
- 配置文件导入c3p0
- 导入包
- 创建连接池
package com.fy.utils;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import javax.sql.DataSource;
public class JdbcUtils {
//提供c3p0的day0904的连接池
private static DataSource ds = new ComboPooledDataSource("myc3p0");
public static DataSource getDataSource(){
return ds;
}
}
3. User
package com.fy.domain;
public class User {
private int id;
private String username;
private String password;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
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;
}
}
4. UserDao(Dbutils)
package com.fy.dao;
import com.fy.domain.User;
import com.fy.utils.JdbcUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
//登录功能
public class UserDao {
public User login(User u) throws Exception{
QueryRunner qr = new QueryRunner(JdbcUtils.getDataSource());
String sql = "select * from user where username = ? and password = ?";
return qr.query(sql, new BeanHandler<User>(User.class) ,u.getUsername(),u.getPassword());
}
}
5. 代码实现
package com.fy.servlet;
import com.fy.dao.UserDao;
import com.fy.domain.User;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
import java.net.URLEncoder;
//自定义到服务器名称
@WebServlet("/login")
public class LoginServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//编码设置
request.setCharacterEncoding("utf-8");
String username = request.getParameter("user");
String password = request.getParameter("pwd");
User u = new User();
u.setUsername(username);
u.setPassword(password);
UserDao dao = new UserDao();
User user = null;
try {
user = dao.login(u);
} catch (Exception e) {
e.printStackTrace();
}
if(user == null){
// 登录失败
Cookie userCookie = new Cookie("username", "");
Cookie pwdCookie = new Cookie("password", "");
Cookie checkCookie = new Cookie("check", "");
userCookie.setMaxAge(0);
pwdCookie.setMaxAge(0);
checkCookie.setMaxAge(0);
userCookie.setPath(request.getContextPath()+"/login.jsp");
pwdCookie.setPath(request.getContextPath()+"/login.jsp");
checkCookie.setPath(request.getContextPath()+"/login.jsp");
response.addCookie(userCookie);
response.addCookie(pwdCookie);
response.addCookie(checkCookie);
HttpSession session = request.getSession();
session.setAttribute("login_error", "用户名或者密码有误");
response.sendRedirect(request.getContextPath()+"/login.jsp");
}
else{
// 登录成功
String check = request.getParameter("check");
System.out.println(check);
if(check != null){
// 勾选了记住密码
username = URLEncoder.encode(username, "utf-8");
Cookie userCookie = new Cookie("username", username);
Cookie pwdCookie = new Cookie("password", password);
Cookie checkCookie = new Cookie("check", "checked");
userCookie.setMaxAge(600);
pwdCookie.setMaxAge(600);
checkCookie.setMaxAge(600);
userCookie.setPath(request.getContextPath()+"/login.jsp");
pwdCookie.setPath(request.getContextPath()+"/login.jsp");
checkCookie.setPath(request.getContextPath()+"/login.jsp");
response.addCookie(userCookie);
response.addCookie(pwdCookie);
response.addCookie(checkCookie);
}else{
Cookie userCookie = new Cookie("username", "");
Cookie pwdCookie = new Cookie("password", "");
Cookie checkCookie = new Cookie("check", "");
userCookie.setMaxAge(0);
pwdCookie.setMaxAge(0);
checkCookie.setMaxAge(0);
userCookie.setPath(request.getContextPath()+"/login.jsp");
pwdCookie.setPath(request.getContextPath()+"/login.jsp");
checkCookie.setPath(request.getContextPath()+"/login.jsp");
response.addCookie(userCookie);
response.addCookie(pwdCookie);
response.addCookie(checkCookie);
}
HttpSession session = request.getSession();
session.setAttribute("user", user);
response.sendRedirect(request.getContextPath()+"/home.jsp");
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
6. 运行结果
数据库数据
服务器打开访问, 将数据库中的存储数据信息进行登录
登录成功
项目总览
