一、需求
1.实现分层架构:bean dao service controller层
2.基于Servlet实现controller:登录成功进入欢迎页面;登录失败重新登录,并显示上次的登录用户名
3.前端:登录页面login.jsp 欢迎页面success.jsp
二、项目结构
bean层
User.java
package bean;
public class User {
private int id;
private String pwd;
private String nickname;
private String addr;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
public String getNickname() {
return nickname;
}
public void setNickname(String nickname) {
this.nickname = nickname;
}
public String getAddr() {
return addr;
}
public void setAddr(String addr) {
this.addr = addr;
}
public User(int id, String pwd, String nickname, String addr) {
super();
this.id = id;
this.pwd = pwd;
this.nickname = nickname;
this.addr = addr;
}
public User() {
super();
}
}
View Code
dao层
UserDAO.java
package dao;
import bean.User;
public interface UserDAO {
User selectUserById(int id);
}
View Code
UserDaoImpl.java
package dao;
import bean.User;
public class UserDaoImpl implements UserDAO {
@Override
public User selectUserById(int id) {
if(id==1) {
return new User(1,"123456","张三","山东烟台市莱山区");
} else {
return null;
}
}
}
View Code
service层
UserService.java
package service;
import bean.User;
public interface UserService {
boolean login(User user);
}
View Code
UserServiceImpl.java
package service;
import bean.User;
import dao.UserDAO;
public class UserServiceImpl implements UserService{
private UserDAO dao;
public UserServiceImpl(UserDAO dao) {
this.dao = dao;
}
@Override
public boolean login(User user) {
User userDB=dao.selectUserById(user.getId());
if(userDB!=null && userDB.getPwd().contentEquals(user.getPwd())) {
user.setNickname(userDB.getNickname());
user.setAddr(userDB.getAddr());
return true;
}else
return false;
}
}
View Code
controller层
checkLogin.java
检测登录情况
package controller;
import java.io.IOException;
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 bean.User;
import dao.UserDaoImpl;
import service.UserService;
import service.UserServiceImpl;
/**
* Servlet implementation class checkLogin
*/
@WebServlet("/checkLogin")
public class checkLogin extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public checkLogin() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.getWriter().append("Served at: ").append(request.getContextPath());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1处理请求参数
//2调用service进行处理
//3根据处理结果,重定向转发到Servlet jsp
request.setCharacterEncoding("utf-8");
String id=request.getParameter("name");
String pwd = request.getParameter("pwd");
UserService service = new UserServiceImpl(new UserDaoImpl());
User user=new User();
user.setId(Integer.parseInt(id));
user.setPwd(pwd);
if(service.login(user))//密码验证 登录成功进入欢迎页面
{
request.setAttribute("user",user.getNickname());
request.getRequestDispatcher("\\success.jsp").forward(request, response);
}
else//登录失败重新登录,并显示上次的登录用户名
{
request.setAttribute("name",user.getNickname());
request.getRequestDispatcher("\\login.jsp").forward(request, response);
}
}
}
前端
login.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>登录页面</title>
</head>
<body>
<form method="post" action=checkLogin>
<table>
<tr>
<td>输入用户名:</td>
<td><input type="text" name="name" value=<%=request.getAttribute("user") %>>
</td>
</tr>
<tr>
<td>输入密码:</td>
<td><input type="password" name="pwd" value=<%=request.getParameter("pwd")%>>
</td>
</tr>
<tr >
<td colspan=2><input type="submit" value="登录"></td>
</tr>
</table>
</form>
</body>
</html>
success.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@page import="java.util.*,bean.*"%>>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>欢迎页面</title>
</head>
<body>
<h1>登录成功</h1>
<h2>
欢迎您!<%=request.getAttribute("user")%>
</h2>
</body>
</html>