Javaweb - MyBatis 精华篇

//pojo 实体类层
public class User {
    private Integer id;
    private String name;
    private String username;
    private String gender;
    private Short age;
 
    public User(Integer id, String name, String username,String gender, Short age) {
        this.id = id;
        this.name = name;
        this.username = username;
        this.gender = gender;
        this.age = age;
    }
 
    public User() {
    }
 
    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", username='" + username + '\'' +
                ", gender=" + gender +
                ", age=" + age +
                '}';
    }
 
    public Integer getId() {
        return id;
    }
 
    public void setId(Integer id) {
        this.id = id;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
 
    public String getUsername() {
        return username;
    }
 
    public void setUsername(String username) {
        this.username = username;
    }
 
    public String getGender() {
        return gender;
    }
 
    public void setGender(String gender) {
        this.gender = gender;
    }
 
    public Short getAge() {
        return age;
    }
 
    public void setAge(Short age) {
        this.age = age;
    }
}
 
//业务逻辑层
@Mapper//在运行时，会自动生成该接口的实现类对象（代理对象），并且将该对象交给IOC容器管理
public interface UserMapper {
    //查询全部用户对象
    @Select("select * from t_user")
    public List<User>  list();
 
}
 
//测试层面
 
@SpringBootTest
class SpringbootMybatisQuickstartApplicationTests {
    @Autowired//将UserMapper 此接口需要在接口前声明@Mapper注解  放入IOC 容器管理的对象创建出来
    private UserMapper userMapper;
 
    @Test
    void textListUser() {
        List<User> list = userMapper.list();
        list.stream().forEach(user ->  System.out.println(user));
    }
 
}