---

📁 示例项目结构（基于 Maven）

user-management/
├── src/
│   ├── main/
│   │   ├── java/
│   │   │   └── com/example/usermanagement/
│   │   │       ├── controller/
│   │   │       │   └── UserController.java
│   │   │       ├── service/
│   │   │       │   ├── UserService.java
│   │   │       │   └── impl/
│   │   │       │       └── UserServiceImpl.java
│   │   │       ├── mapper/
│   │   │       │   └── UserMapper.java
│   │   │       ├── entity/
│   │   │       │   └── User.java
│   │   │       └── UserManagementApplication.java
│   │   ├── resources/
│   │   │   ├── mapper/
│   │   │   │   └── UserMapper.xml
│   │   │   ├── application.yml
│   │   │   └── logback-spring.xml (可选)
│   └── test/
│       └── java/
│           └── com/example/usermanagement/
│               └── UserServiceTests.java
├── pom.xml

---

各部分说明：

🧱 User.java（实体类）

package com.example.usermanagement.entity;

public class User {
    private Integer id;
    private String name;
    private String email;

    // Getters & Setters
}

---

🧩 UserMapper.java（Mapper 接口）

package com.example.usermanagement.mapper;

import com.example.usermanagement.entity.User;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

@Mapper
public interface UserMapper {
    User findById(Integer id);
    List<User> findAll();
    int insert(User user);
    int update(User user);
    int deleteById(Integer id);
}

---

📄 UserMapper.xml（XML 映射文件）

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
  PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.example.usermanagement.mapper.UserMapper">

    <select id="findById" resultType="com.example.usermanagement.entity.User">
        SELECT * FROM user WHERE id = #{id}
    </select>

    <select id="findAll" resultType="com.example.usermanagement.entity.User">
        SELECT * FROM user
    </select>

    <insert id="insert">
        INSERT INTO user(name, email) VALUES (#{name}, #{email})
    </insert>

    <update id="update">
        UPDATE user SET name=#{name}, email=#{email} WHERE id=#{id}
    </update>

    <delete id="deleteById">
        DELETE FROM user WHERE id=#{id}
    </delete>

</mapper>

---

🧠 UserService.java 和 UserServiceImpl.java

public interface UserService {
    User getUserById(Integer id);
    List<User> getAllUsers();
    void addUser(User user);
    void updateUser(User user);
    void deleteUser(Integer id);
}

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

    public User getUserById(Integer id) {
        return userMapper.findById(id);
    }

    public List<User> getAllUsers() {
        return userMapper.findAll();
    }

    public void addUser(User user) {
        userMapper.insert(user);
    }

    public void updateUser(User user) {
        userMapper.update(user);
    }

    public void deleteUser(Integer id) {
        userMapper.deleteById(id);
    }
}

---

🌐 UserController.java

@RestController
@RequestMapping("/users")
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping("/{id}")
    public User getUser(@PathVariable Integer id) {
        return userService.getUserById(id);
    }

    @GetMapping
    public List<User> getAllUsers() {
        return userService.getAllUsers();
    }

    @PostMapping
    public void addUser(@RequestBody User user) {
        userService.addUser(user);
    }

    @PutMapping
    public void updateUser(@RequestBody User user) {
        userService.updateUser(user);
    }

    @DeleteMapping("/{id}")
    public void deleteUser(@PathVariable Integer id) {
        userService.deleteUser(id);
    }
}

---

⚙️ application.yml

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/user_db?useSSL=false&serverTimezone=UTC
    username: root
    password: yourpassword
    driver-class-name: com.mysql.cj.jdbc.Driver

  mybatis:
    mapper-locations: classpath:mapper/*.xml
    type-aliases-package: com.example.usermanagement.entity

---

🚀 UserManagementApplication.java

@SpringBootApplication
public class UserManagementApplication {
    public static void main(String[] args) {
        SpringApplication.run(UserManagementApplication.class, args);
    }
}

---