Spring使用RowMapper将数据中的每一行封装成用户定义的类

Posted 2020-08-14

1.dao

public interface MapperSelecteAllEmpDao {
    public List<Emp> all();
}

2.实现类

public class MapperAllEmpImpl extends JdbcDaoSupport implements
        MapperSelecteAllEmpDao {

    @Override
    public List<Emp> all() {
        String sql = "select * from emp";
        List<Emp> list = this.getJdbcTemplate().query(sql, new EmpRowMapper());
        return list;
    }
}

3.继承rowMapper接口，返回自定义类型

public class EmpRowMapper implements RowMapper<Emp> {

    @Override
    public Emp mapRow(ResultSet rs, int arg1) throws SQLException {
        Emp emp = new Emp();
        emp.setId(rs.getInt("id"));
        emp.setName(rs.getString("name"));
        emp.setAge(rs.getInt("age"));
        return emp;
    }
}

4.测试

@Test
    // Spring使用rowMapper查询表中所有记录
    public void rowMapperAll() {
        ApplicationContext ac = new ClassPathXmlApplicationContext(
                "applicationContext.xml");

        MapperSelecteAllEmpDao mapperSelectAll = (MapperSelecteAllEmpDao) ac
                .getBean("mapperAll");

        List<Emp> empList = mapperSelectAll.all();

        for (Emp emp : empList) {
            System.out.println(emp.getName());
        }
    }