controller层，mapper层.domain层，service层详细描述

当我们进行Java Web应用程序的开发时，通常会采用四层架构。下面是每个层次的详细描述：

1. Controller层：这个层次负责接收和处理HTTP请求，相当于Web应用程序的入口。它的主要职责是从请求中提取出必要的参数，调用Service层的方法来处理业务逻辑，然后将结果返回给客户端。Controller层通常由Spring MVC、Struts等Web框架提供支持。

2. Service层：这个层次负责实现业务逻辑和业务流程。它是整个应用程序的核心，负责处理各种业务需求，比如用户注册、登录、商品购买等等。Service层通常由Spring框架提供支持，其中包括声明式事务管理、AOP、IOC等功能。

3. Mapper层：这个层次负责与数据库进行交互，实现数据的CRUD操作。Mapper层通常由MyBatis框架提供支持，它的主要特点是使用XML文件来描述SQL语句，从而将Java代码和SQL语句进行分离，使得代码更加清晰、易于维护。

4. Domain层：这个层次定义了数据模型和业务实体。它是整个应用程序的基础，负责封装数据、定义业务对象、提供数据校验等功能。Domain层通常由JavaBean来实现，其中包括POJO、DTO、VO等对象，它们在整个应用程序中都是非常重要的组成部分。

总之，四层架构是一种非常有效的开发模式，可以帮助我们更好地组织代码、分离关注点，从而提高应用程序的可维护性、可扩展性和可重用性。

相关问题

controller层，mapper层.domain层，service层

这是一个典型的四层架构，通常用于Java Web应用程序的开发。其中，controller层负责接收和处理HTTP请求，mapper层负责与数据库进行交互，domain层定义了数据模型和业务实体，service层则负责实现业务逻辑和业务流程。这个四层架构可以有效地分离不同的关注点，使得代码更加清晰、易于维护。

用springboot springsecurity mybatisplus写一个登录以及退出的权限设置 含有domain层 controller层 service层以及mapper层

好的，下面是一个简单的示例代码：

1. 首先，创建一个User实体类，用于存储用户信息

package com.example.demo.domain;

import lombok.Data;

@Data
public class User {
    private Long id;
    private String username;
    private String password;
    private String role;
}

2. 创建一个UserMapper接口，用于操作数据库

package com.example.demo.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.demo.domain.User;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface UserMapper extends BaseMapper<User> {
}

3. 创建一个UserService接口及其实现类，用于处理业务逻辑

package com.example.demo.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.example.demo.domain.User;

public interface UserService extends IService<User> {
    User getUserByUsername(String username);
}

package com.example.demo.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.example.demo.domain.User;
import com.example.demo.mapper.UserMapper;
import com.example.demo.service.UserService;
import org.springframework.stereotype.Service;

@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {

    @Override
    public User getUserByUsername(String username) {
        return lambdaQuery().eq(User::getUsername, username).one();
    }
}

4. 创建一个WebSecurityConfig类，用于配置Spring Security

package com.example.demo.config;

import com.example.demo.handler.CustomAuthenticationFailureHandler;
import com.example.demo.handler.CustomAuthenticationSuccessHandler;
import com.example.demo.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private UserService userService;

    @Autowired
    private CustomAuthenticationSuccessHandler customAuthenticationSuccessHandler;

    @Autowired
    private CustomAuthenticationFailureHandler customAuthenticationFailureHandler;

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
                .antMatchers("/", "/login").permitAll()
                .anyRequest().authenticated()
                .and()
                .formLogin()
                .loginPage("/login")
                .successHandler(customAuthenticationSuccessHandler)
                .failureHandler(customAuthenticationFailureHandler)
                .permitAll()
                .and()
                .logout()
                .logoutSuccessUrl("/")
                .permitAll();
    }

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(userDetailsService()).passwordEncoder(passwordEncoder());
    }

    @Bean
    public UserDetailsService userDetailsService() {
        return username -> userService.getUserByUsername(username);
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }
}

5. 创建一个CustomAuthenticationSuccessHandler类和一个CustomAuthenticationFailureHandler类，用于处理登录成功和登录失败的逻辑

package com.example.demo.handler;

import org.springframework.security.core.Authentication;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.web.authentication.SimpleUrlAuthenticationSuccessHandler;
import org.springframework.stereotype.Component;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Component
public class CustomAuthenticationSuccessHandler extends SimpleUrlAuthenticationSuccessHandler {

    @Override
    public void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response,
                                        Authentication authentication) throws IOException, ServletException {
        UserDetails userDetails = (UserDetails) authentication.getPrincipal();
        request.getSession().setAttribute("username", userDetails.getUsername());
        super.onAuthenticationSuccess(request, response, authentication);
    }
}

package com.example.demo.handler;

import org.springframework.security.authentication.BadCredentialsException;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.authentication.SimpleUrlAuthenticationFailureHandler;
import org.springframework.stereotype.Component;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Component
public class CustomAuthenticationFailureHandler extends SimpleUrlAuthenticationFailureHandler {

    @Override
    public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response,
                                        AuthenticationException exception) throws IOException, ServletException {
        if (exception.getClass().isAssignableFrom(BadCredentialsException.class)) {
            response.sendRedirect("/login?error=1");
        } else {
            super.onAuthenticationFailure(request, response, exception);
        }
    }
}

6. 创建一个UserController类，用于处理登录和退出的请求

package com.example.demo.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;

@Controller
public class UserController {

    @GetMapping("/")
    public String index() {
        return "index";
    }

    @GetMapping("/login")
    public String login() {
        return "login";
    }

    @PostMapping("/logout")
    public String logout() {
        return "redirect:/";
    }
}

7. 最后，创建一个login.html页面和一个index.html页面，用于展示登录和退出的效果

login.html：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Login</title>
</head>
<body>
<h1>Login</h1>
<form action="/login" method="post">
    <p><label>Username:</label> <input type="text" name="username"></p>
    <p><label>Password:</label> <input type="password" name="password"></p>
    <p><input type="submit" value="Login"></p>
</form>
<c:if test="${param.error != null}">
    <p style="color: red">Incorrect username or password.</p>
</c:if>
</body>
</html>

index.html：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Index</title>
</head>
<body>
<h1>Hello, ${sessionScope.username}!</h1>
<form action="/logout" method="post">
    <p><input type="submit" value="Logout"></p>
</form>
</body>
</html>

以上就是一个简单的Spring Boot + Spring Security + MyBatis Plus的登录以及退出的权限设置示例代码。