用户模块实现

用户模块是商城系统的基础模块，包括用户注册、登录、信息查询等功能。本节将学习如何实现完整的用户模块。

本节将学习：用户注册、用户登录、用户信息查询，以及密码加密（BCrypt）。

用户注册

注册流程

注册实现

package com.example.ecommerce.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.example.ecommerce.entity.User;
import com.example.ecommerce.exception.BusinessException;
import com.example.ecommerce.mapper.UserMapper;
import com.example.ecommerce.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {
    
    @Autowired
    private PasswordEncoder passwordEncoder;
    
    @Override
    @Transactional(rollbackFor = Exception.class)
    public User register(User user) {
        // 1. 检查用户名是否已存在
        User existUser = baseMapper.selectOne(
            new LambdaQueryWrapper<User>()
                .eq(User::getUsername, user.getUsername())
        );
        if (existUser != null) {
            throw new BusinessException("Username already exists");
        }
        
        // 2. 检查邮箱是否已存在
        existUser = baseMapper.selectOne(
            new LambdaQueryWrapper<User>()
                .eq(User::getEmail, user.getEmail())
        );
        if (existUser != null) {
            throw new BusinessException("Email already exists");
        }
        
        // 3. 加密密码
        user.setPassword(passwordEncoder.encode(user.getPassword()));
        
        // 4. 设置默认状态
        user.setStatus(1);
        
        // 5. 保存用户
        save(user);
        
        return user;
    }
}

Controller 实现

@PostMapping("/register")
public Result<User> register(@RequestBody @Valid User user) {
    User registered = userService.register(user);
    return Result.success("User registered successfully", registered);
}

用户登录

登录流程

登录实现

@Override
public User login(String username, String password) {
    // 1. 根据用户名查询用户
    User user = baseMapper.selectOne(
        new LambdaQueryWrapper<User>()
            .eq(User::getUsername, username)
    );
    
    if (user == null) {
        throw new BusinessException("Invalid username or password");
    }
    
    // 2. 检查用户状态
    if (user.getStatus() == 0) {
        throw new BusinessException("User is disabled");
    }
    
    // 3. 验证密码
    if (!passwordEncoder.matches(password, user.getPassword())) {
        throw new BusinessException("Invalid username or password");
    }
    
    return user;
}

Controller 实现

@PostMapping("/login")
public Result<User> login(@RequestParam String username, 
                          @RequestParam String password) {
    User user = userService.login(username, password);
    return Result.success("Login successful", user);
}

用户信息查询

查询实现

@Override
public User getById(Long id) {
    User user = super.getById(id);
    if (user == null) {
        throw new BusinessException("User not found");
    }
    // 清除敏感信息
    user.setPassword(null);
    return user;
}

@Override
public User getByUsername(String username) {
    return baseMapper.selectOne(
        new LambdaQueryWrapper<User>()
            .eq(User::getUsername, username)
    );
}

@Override
public User getByEmail(String email) {
    return baseMapper.selectOne(
        new LambdaQueryWrapper<User>()
            .eq(User::getEmail, email)
    );
}

Controller 实现

@GetMapping("/{id}")
public Result<User> getUser(@PathVariable Long id) {
    User user = userService.getById(id);
    return Result.success(user);
}

@GetMapping("/username/{username}")
public Result<User> getUserByUsername(@PathVariable String username) {
    User user = userService.getByUsername(username);
    if (user == null) {
        throw new BusinessException("User not found");
    }
    return Result.success(user);
}

密码加密（BCrypt）

BCrypt 简介

BCrypt 是一种密码哈希函数，专门用于密码存储。它使用盐值（salt）和可配置的成本因子，提供强大的密码加密。

PasswordEncoder 配置

package com.example.ecommerce.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.security.crypto.password.PasswordEncoder;

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

密码加密使用

@Autowired
private PasswordEncoder passwordEncoder;

// 加密密码
String encodedPassword = passwordEncoder.encode("plainPassword");

// 验证密码
boolean matches = passwordEncoder.matches("plainPassword", encodedPassword);

密码更新

@Override
@Transactional(rollbackFor = Exception.class)
public boolean updatePassword(Long userId, String oldPassword, String newPassword) {
    User user = getById(userId);
    if (user == null) {
        throw new BusinessException("User not found");
    }
    
    // 验证旧密码
    if (!passwordEncoder.matches(oldPassword, user.getPassword())) {
        throw new BusinessException("Invalid old password");
    }
    
    // 加密新密码
    user.setPassword(passwordEncoder.encode(newPassword));
    
    // 更新密码
    return updateById(user);
}

完整用户模块示例

UserService 接口

package com.example.ecommerce.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.example.ecommerce.entity.User;

public interface UserService extends IService<User> {
    User register(User user);
    User login(String username, String password);
    User getByUsername(String username);
    User getByEmail(String email);
    boolean updatePassword(Long userId, String oldPassword, String newPassword);
    boolean updateProfile(Long userId, User user);
}

UserController 完整示例

package com.example.ecommerce.controller;

import com.example.ecommerce.common.Result;
import com.example.ecommerce.entity.User;
import com.example.ecommerce.service.UserService;
import jakarta.validation.Valid;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/api/users")
public class UserController {
    
    @Autowired
    private UserService userService;
    
    @PostMapping("/register")
    public Result<User> register(@RequestBody @Valid User user) {
        User registered = userService.register(user);
        return Result.success("User registered successfully", registered);
    }
    
    @PostMapping("/login")
    public Result<User> login(@RequestParam String username, 
                              @RequestParam String password) {
        User user = userService.login(username, password);
        return Result.success("Login successful", user);
    }
    
    @GetMapping("/{id}")
    public Result<User> getUser(@PathVariable Long id) {
        User user = userService.getById(id);
        return Result.success(user);
    }
    
    @PutMapping("/{id}")
    public Result<User> updateUser(@PathVariable Long id, 
                                   @RequestBody @Valid User user) {
        user.setId(id);
        userService.updateById(user);
        return Result.success("User updated successfully", user);
    }
    
    @PutMapping("/{id}/password")
    public Result<?> updatePassword(@PathVariable Long id,
                                     @RequestParam String oldPassword,
                                     @RequestParam String newPassword) {
        userService.updatePassword(id, oldPassword, newPassword);
        return Result.success("Password updated successfully");
    }
}

官方资源

Spring Security PasswordEncoder：https://docs.spring.io/spring-security/reference/features/authentication/password-storage.html
BCrypt 算法：https://en.wikipedia.org/wiki/Bcrypt

本节小结

在本节中，我们实现了：

第一个是用户注册。 检查用户名和邮箱是否已存在，加密密码后保存用户。

第二个是用户登录。 验证用户名和密码，检查用户状态。

第三个是用户信息查询。 根据 ID、用户名、邮箱查询用户信息。

第四个是密码加密。 使用 BCrypt 加密密码，确保密码安全。

这就是用户模块实现。用户模块是系统的基础，为其他模块提供用户认证和授权支持。

在下一节，我们将学习如何实现商品模块，包括商品管理、商品搜索等功能。