Mybatis 05 注解实现增删改查

public interface UserMapper {
    /*注解实现增删改查*/
    @Select("select * from tb_user")
    List<User> selectAll2();
    @Insert("insert into tb_user values(null,#{username},#{password},#{gender},#{addr})")
    void insert(User user);
    @Update("update tb_user set username=#{username},password=#{password},gender=#{gender},addr=#{addr} where id=#{id}")
    void updateUser(User user);
    @Delete("delete from tb_user where id=#{id}")
    void delete(int id);
}

import com.entity.Brand;
import com.entity.User;
import com.mapper.BrandMapper;
import com.mapper.UserMapper;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

public class TestUser {
/*注解实现增删改查*/
    @Test
    public void testSelectAll2() throws IOException {
        //1. 加载mybatis的核心配置文件，获取 SqlSessionFactory
        InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

        //2. 获取SqlSession对象，用它来执行sql
        SqlSession sqlSession = sqlSessionFactory.openSession();
        //3. 执行sql
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> list = mapper.selectAll2();
        System.out.println(list);
        //4. 释放资源
        sqlSession.close();
    }

    @Test
    public void testInsert() throws IOException {
        //1. 加载mybatis的核心配置文件，获取 SqlSessionFactory
        InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession(true);
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        User user = new User(null,"王王","123","男","赣州");
        mapper.insert(user);
        sqlSession.close();
    }

    @Test
    public void testUpdate() throws IOException {
        InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession(true);
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        User user = new User(4,"王维","123","男","赣州");
        mapper.updateUser(user);
        sqlSession.close();
    }
    @Test
    public void testDelete() throws IOException {
        InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession(true);
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        mapper.delete(4);
        sqlSession.close();
    }

}