1、新增pom依賴

<!-- mysql -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.46</version>
</dependency>
<!-- mybatis -->
<dependency>
    <groupId>org.mybatis.spring.boot</
 
groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.3.2</version>
</dependency>
<!-- springboot實現熱部署 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-devtools</artifactId
 
>
    <optional>true</optional>
</dependency>
<!-- 單元測試 -->
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
</dependency>

2、註解方式配置

application.properties

mybatis.type-aliases-package
 
=cn.xupengzhuang.entity
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/zhuang-blogger?useUnicode=true&characterEncoding=utf-8
spring.datasource.username=root
spring.datasource.password=root

springboot會自動載入spring.datasource.*相關配置，資料來源就會自動注入到sqlSessionFactory中，sqlSessionFactory會自動注入到Mapper中

啟動類中新增對mapper包掃描

@SpringBootApplication
@MapperScan("cn.xupengzhuang.mapper")
public class ZhuangBloggerApplication {

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

}

3、實體類

public class UserEntity {
    private static final long serialVersionUID = 1L;
    private Long id;
    private String userName;
    private String passWord;
    private UserSexEnum userSex;
    private String nickName;

    public UserEntity() {
        super();
    }

    public UserEntity(String userName, String passWord, UserSexEnum userSex) {
        super();
        this.passWord = passWord;
        this.userName = userName;
        this.userSex = userSex;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long 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;
    }

    public UserSexEnum getUserSex() {
        return userSex;
    }

    public void setUserSex(UserSexEnum userSex) {
        this.userSex = userSex;
    }

    public String getNickName() {
        return nickName;
    }

    public void setNickName(String nickName) {
        this.nickName = nickName;
    }

    @Override
    public String toString() {
        // TODO Auto-generated method stub
        return "userName " + this.userName + ", pasword " + this.passWord + "sex " + userSex.name();
    }
}

4、列舉類

public enum UserSexEnum {
    MAN, WOMAN
}

5、開發Mapper

public interface UserMapper {
    @Select("SELECT * FROM users")
    @Results({
            @Result(property = "userSex",  column = "user_sex", javaType = UserSexEnum.class),
            @Result(property = "nickName", column = "nick_name")
    })
    List<UserEntity> getAll();

    @Select("SELECT * FROM users WHERE id = #{id}")
    @Results({
            @Result(property = "userSex",  column = "user_sex", javaType = UserSexEnum.class),
            @Result(property = "nickName", column = "nick_name")
    })
    UserEntity getOne(Long id);

    @Insert("INSERT INTO users(userName,passWord,user_sex) VALUES(#{userName}, #{passWord}, #{userSex})")
    void insert(UserEntity user);

    @Update("UPDATE users SET userName=#{userName},nick_name=#{nickName} WHERE id =#{id}")
    void update(UserEntity user);

    @Delete("DELETE FROM users WHERE id =#{id}")
    void delete(Long id);

}

6、使用

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

    @Autowired
    private UserMapper userMapper;

    @GetMapping("/getUsers")
    public List<UserEntity> getUsers() {
        List<UserEntity> users=userMapper.getAll();
        return users;
    }

    @GetMapping("/getUser/{id}")
    public UserEntity getUser(@PathVariable("id") Long id) {
        UserEntity user=userMapper.getOne(id);
        return user;
    }

    @PostMapping("/add")
    public void save(UserEntity user) {
        userMapper.insert(user);
    }

    @PutMapping("/update")
    public void update(UserEntity user) {
        userMapper.update(user);
    }

    @DeleteMapping("/delete/{id}")
    public void delete(@PathVariable("id") Long id) {
        userMapper.delete(id);
    }
}

7、測試

@RunWith(SpringRunner.class)
@SpringBootTest
public class UserMapperTest {
    @Autowired
    private UserMapper userMapper;

    @Test
    public void testInsert() throws Exception {
        userMapper.insert(new UserEntity("aa", "a123456", UserSexEnum.MAN));
        userMapper.insert(new UserEntity("bb", "b123456", UserSexEnum.WOMAN));
        userMapper.insert(new UserEntity("cc", "b123456", UserSexEnum.WOMAN));

        Assert.assertEquals(3, userMapper.getAll().size());
    }

    @Test
    public void testQuery() throws Exception {
        List<UserEntity> users = userMapper.getAll();
        System.out.println(users.toString());
    }

    @Test
    public void testUpdate() throws Exception {
        UserEntity user = userMapper.getOne(30l);
        System.out.println(user.toString());
        user.setNickName("neo");
        userMapper.update(user);
        Assert.assertTrue(("neo".equals(userMapper.getOne(30l).getNickName())));
    }
}