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📁 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

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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
}

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🧩 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);
}

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📄 UserMapper.xml（XML 映射文件）

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//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>

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🧠 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 {@Autowiredprivate 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);}
}

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🌐 UserController.java

@RestController
@RequestMapping("/users")
public class UserController {@Autowiredprivate UserService userService;@GetMapping("/{id}")public User getUser(@PathVariable Integer id) {return userService.getUserById(id);}@GetMappingpublic List<User> getAllUsers() {return userService.getAllUsers();}@PostMappingpublic void addUser(@RequestBody User user) {userService.addUser(user);}@PutMappingpublic void updateUser(@RequestBody User user) {userService.updateUser(user);}@DeleteMapping("/{id}")public void deleteUser(@PathVariable Integer id) {userService.deleteUser(id);}
}

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⚙️ application.yml

spring:datasource:url: jdbc:mysql://localhost:3306/user_db?useSSL=false&serverTimezone=UTCusername: rootpassword: yourpassworddriver-class-name: com.mysql.cj.jdbc.Drivermybatis:mapper-locations: classpath:mapper/*.xmltype-aliases-package: com.example.usermanagement.entity

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🚀 UserManagementApplication.java

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

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