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，password

1.带有依赖，yml配置，mapper.xml，entity，mapper，service，controller，application

pom.xml

<dependencies>
    <!-- Spring Boot Starter -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>

    <!-- MyBatis Starter -->
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.1.3</version>
    </dependency>

    <!-- MySQL Connector -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.23</version>
    </dependency>

    <!-- Spring Boot Starter Test -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

application.yml

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/mydb
    username: root
    password: root
    driver-class-name: com.mysql.cj.jdbc.Driver
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true
  main:
    web-application-type: servlet
mybatis:
  mapper-locations: classpath:mapper/*.xml

UserMapper.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.mapper.UserMapper">
    <resultMap id="UserMap" type="com.example.entity.User">
        <id column="id" property="id"/>
        <result column="username" property="username"/>
        <result column="password" property="password"/>
    </resultMap>

    <select id="getUserById" resultMap="UserMap" parameterType="int">
        SELECT * FROM user WHERE id = #{id}
    </select>

    <select id="getUserByUsername" resultMap="UserMap" parameterType="string">
        SELECT * FROM user WHERE username = #{username}
    </select>

    <insert id="insertUser" parameterType="com.example.entity.User">
        INSERT INTO user(username, password) VALUES (#{username}, #{password})
    </insert>

    <update id="updateUser" parameterType="com.example.entity.User">
        UPDATE user SET username = #{username}, password = #{password} WHERE id = #{id}
    </update>

    <delete id="deleteUser" parameterType="int">
        DELETE FROM user WHERE id = #{id}
    </delete>
</mapper>

User.java

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

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

UserMapper.java

@Mapper
public interface UserMapper {
    User getUserById(int id);

    User getUserByUsername(String username);

    void insertUser(User user);

    void updateUser(User user);

    void deleteUser(int id);
}

UserService.java

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

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

    public User getUserByUsername(String username) {
        return userMapper.getUserByUsername(username);
    }

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

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

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

UserController.java

@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    private UserService userService;

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

    @GetMapping("/username/{username}")
    public User getUserByUsername(@PathVariable String username) {
        return userService.getUserByUsername(username);
    }

    @PostMapping("/")
    public void insertUser(@RequestBody User user) {
        userService.insertUser(user);
    }

    @PostMapping("/{id}")
    public void updateUser(@PathVariable int id, @RequestBody User user) {
        user.setId(id);
        userService.updateUser(user);
    }

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

Application.java

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

2.要有注释

注释已添加在代码中。

3.entity为user，属性为id，username，password

User.java

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

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}