【Mybatis】初识Mybatis与快速入门第一个程序（下）

public class User {
    private int id;
    private String name;
    private String password;
    public User() {
    }
    public User(int id, String name, String password) {
        this.id = id;
        this.name = name;
        this.password = password;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

//工具类 sqlSessionFactory -->sqlSession
public class MybatisUtils {
    private static SqlSessionFactory sqlSessionFactory;
    static {
        try {
            //使用mybatis获取sqlSessionFactory对象
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    //既然有了 SqlSessionFactory，顾名思义，
    // 我们可以从中获得 SqlSession 的实例。SqlSession 提供了在数据库执行 SQL 命令所需的所有方法。
    // 你可以通过 SqlSession 实例来直接执行已映射的 SQL 语句。
    public static SqlSession getSqlSession() {
          return sqlSessionFactory.openSession();
    }
}

public class UserDaoMapperTest {
    @Test
    public void test(){
        //1.获得sqlSession对象
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        //方法1：getMapper
        UserDaoMapper userDaoMapper = sqlSession.getMapper(UserDaoMapper.class);
        List<User> userList= userDaoMapper.getUserList();
        for (User user:userList){
            System.out.println(user);
        }
        //关闭sqlSession
        sqlSession.close();
    }
}