day02 Spring Boot整合Mybatis进行CRUD

1.在数据库中新建一个数据库，添加一张表

2.创建一个Spring Initializr模块

3.在pom.z中添加依赖

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.39</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.6</version>
            <optional>true</optional>
        </dependency>

4.在自动生成的包下新建entity包、service包、serviceimpl包、mapper包、controller包

5.在entity中新建User类

@Data
public class Course {
    private Long courseId;
    private String courseName;
    private Long userId;
    private String courseClass;
    private String cover;
    private String courseCode;
    private Short finished;
}

（注解不能少，且所有的属性都用封装属性）；

6.在service中新建UserService接口，serviceimpl中实现service方法

public interface UserService {
    List<User> selectAll();

    User getOne(long userId);

    void delete(long userId);

    void insert(User user);

    void update(User user );
}

@Service
public class UserServiceImpl implements UserService {
    @Resource
    private UserMapper userMapper;

    @Override
    public List<User> selectAll() {
        return userMapper.selectAll();
    }

    @Override
    public User getOne(long userId) {
        return userMapper.getOne(userId);
    }

    @Override
    public void delete(long userId) {
        userMapper.delete(userId);
    }

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

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

（注解不要漏掉）

7.在mapper中新建UserMapper接口编写数据库的增删改查方法

public interface UserMapper {
    @Results({@Result(column = "user_id",property = "userId"),
            @Result(column = "mobile",property = "mobile"),
            @Result(column = "password",property = "password"),
            @Result(column = "username",property = "username"),
            @Result(column = "avatar",property = "avatar")
    })
    @Select("SELECT * FROM t_sys_user ")
    List<User> selectAll();


    @Results({@Result(column = "user_id",property = "userId"),
            @Result(column = "mobile",property = "mobile"),
            @Result(column = "password",property = "password"),
            @Result(column = "username",property = "username"),
            @Result(column = "avatar",property = "avatar")
    })
    @Select("SELECT * FROM t_sys_user WHERE user_id = #{userId} ")
    User getOne(Long userId);

    @Delete("DELETE FROM t_sys_user WHERE user_id = #{userId} ")
    void delete(Long userId);

    @Insert("INSERT INTO t_sys_user(mobile,password,username,avatar) VALUES(#{mobile},#{password},#{username},#{avatar})")
    void insert(User user);

    @Update("UPDATE t_sys_user SET username=#{username},password=#{password},avatar=#{avatar} WHERE user_id=#{userId} ")
    void update(User user);
}

8.在resources的application.properties中添加数据库驱动和指定文件映射

##数据库配置
spring.datasource.url=jdbc:mysql://localhost:3306/db_spring?useUnicode=true&characterEncoding=utf-8&useSSL=false
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

#指定实体类映射的包
mybatis.type-aliases-package=com.springboot.mybatis.entity

9.对UserServiceImpl进行单元测试，无异常通过CRUD

@RunWith(SpringRunner.class)
@SpringBootTest
public class UserServiceImplTest {

    @Resource
    private UserService userService;

    @Test
    public void selectAll() {
        List<User> userList=userService.selectAll();
        userList.forEach(user -> System.out.println(user));
    }

    @Test
    public void getOne() {
        User user=userService.getOne(1);
        System.out.println(user);
    }

    @Test
    public void delete() {
        userService.delete(1);
    }

    @Test
    public void insert() {
        User user=new User();
        user.setMobile("14531321864");
        user.setPassword("444");
        user.setUsername("张壮壮");
        user.setAvatar("user4.jpg");
        userService.insert(user);
    }

    @Test
    public void update() {
        User user=userService.getOne(3L);
        user.setAvatar("1.jpg");
        userService.update(user);
    }
}

（注解！）

9.运行SpringbootMybatisApplication

@SpringBootApplication
@MapperScan("com.springboot.mybatis.mapper")
public class SpringbootMybatisApplication {

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

}

（SpringbootMybatisApplication为自动生成，只需在类上在添加MapperScan注解）

10.在controller中新建UserController类

@RestController
@RequestMapping(value = "/api")
public class UserController {

    @Resource
    private UserService userService;

    @RequestMapping(value = "/users",method = RequestMethod.GET)
    public List<User> selectAll(){
        return userService.selectAll();
    }

    @RequestMapping(value = "/user/{id}",method = RequestMethod.GET)
    public User getOne(@PathVariable("id") long id){
        return userService.getOne(id);
    }

    @RequestMapping(value = "/user/{id}",method = RequestMethod.DELETE)
    public void delete(@PathVariable("id") long id){
        userService.delete(id);
    }

    @RequestMapping(value = "/user",method = RequestMethod.POST)
    public void addUser(@RequestBody User user){
        userService.insert(user);
    }

    @RequestMapping(value = "/user",method = RequestMethod.PUT)
    public void updateUser(@RequestBody User user){
        userService.update(user);
    }
}