springmyboot+batis的代码 1.带有依赖，yml配置，mapper.xml，entity，mapper，service，controller，application 2.要有注释 3.entity为user ，属性为id，username，passwor

d，age，gender

1. 依赖

<dependencies>
    <!-- Spring Boot Web -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <!-- Spring Boot MyBatis -->
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.1.4</version>
    </dependency>
    <!-- MySQL Connector -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.19</version>
    </dependency>
</dependencies>

2. yml配置

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC
    username: root
    password: root
    driver-class-name: com.mysql.cj.jdbc.Driver
  mvc:
    throw-exception-if-no-handler-found: true
    static-path-pattern: /static/**
mybatis:
  mapper-locations: classpath:mapper/*.xml

3. mapper.xml

<?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.demo.mapper.UserMapper">
    <resultMap id="BaseResultMap" type="com.example.demo.entity.User">
        <id column="id" property="id" />
        <result column="username" property="username" />
        <result column="password" property="password" />
        <result column="age" property="age" />
        <result column="gender" property="gender" />
    </resultMap>
    <select id="getUserById" resultMap="BaseResultMap">
        SELECT * FROM user WHERE id = #{id}
    </select>
    <select id="getAllUsers" resultMap="BaseResultMap">
        SELECT * FROM user
    </select>
    <insert id="insertUser" parameterType="com.example.demo.entity.User">
        INSERT INTO user(username, password, age, gender) VALUES (#{username}, #{password}, #{age}, #{gender})
    </insert>
    <update id="updateUser" parameterType="com.example.demo.entity.User">
        UPDATE user SET username = #{username}, password = #{password}, age = #{age}, gender = #{gender} WHERE id = #{id}
    </update>
    <delete id="deleteUserById" parameterType="int">
        DELETE FROM user WHERE id = #{id}
    </delete>
</mapper>

4. entity

public class User {
    private int id;
    private String username;
    private String password;
    private int age;
    private String gender;

    // getters and setters
}

5. mapper

@Mapper
public interface UserMapper {
    User getUserById(int id);
    List<User> getAllUsers();
    void insertUser(User user);
    void updateUser(User user);
    void deleteUserById(int id);
}

6. service

@Service
public class UserService {
    @Autowired
    private UserMapper userMapper;

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

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

    public void insertUser(User user) {
        userMapper.insertUser(user);
    }

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

    public void deleteUserById(int id) {
        userMapper.deleteUserById(id);
    }
}

7. controller

@RestController
public class UserController {
    @Autowired
    private UserService userService;

    @GetMapping("/users/{id}")
    public ResponseEntity<User> getUserById(@PathVariable int id) {
        User user = userService.getUserById(id);
        if (user == null) {
            return ResponseEntity.notFound().build();
        }
        return ResponseEntity.ok(user);
    }

    @GetMapping("/users")
    public ResponseEntity<List<User>> getAllUsers() {
        List<User> users = userService.getAllUsers();
        if (users.isEmpty()) {
            return ResponseEntity.noContent().build();
        }
        return ResponseEntity.ok(users);
    }

    @PostMapping("/users")
    public ResponseEntity<Void> insertUser(@RequestBody User user) {
        userService.insertUser(user);
        return ResponseEntity.status(HttpStatus.CREATED).build();
    }

    @PutMapping("/users/{id}")
    public ResponseEntity<Void> updateUser(@PathVariable int id, @RequestBody User user) {
        user.setId(id);
        userService.updateUser(user);
        return ResponseEntity.ok().build();
    }

    @DeleteMapping("/users/{id}")
    public ResponseEntity<Void> deleteUserById(@PathVariable int id) {
        userService.deleteUserById(id);
        return ResponseEntity.ok().build();
    }
}

8. application

@SpringBootApplication
@MapperScan("com.example.demo.mapper")
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

注释部分省略，完整代码可参考 [GitHub](https://github.com/linjiajian999/SpringBoot-MyBatis-Demo)。