单元测试DAO

Question

I've been trying to do a unit test of my DAO but I haven't find out the way to do it yet and I'm feeling a little desperate. I have a tiny DAO that looks like this:

public interface ElectionsDao {
    List<String> getDates();
}

I'm using Spring framework to do DI using SimpleJdbcTemplate . My implementation looks like this:

public class ElectionsDaoImpl extends SimpleJdbcDaoSupport implements ElectionsDao {
    public List<String> getDates() {
        List<String> dates = new ArrayList<String>();
        try {
            dates = getSimpleJdbcTemplate().query("SELECT electiondate FROM electiondate", new StringRowMapper());
        } catch (DataAccessException ex){
            throw new RuntimeException(ex);
        }
        return dates;
    }

    protected static final class StringRowMapper implements ParameterizedRowMapper<String> {
        public String mapRow(ResultSet rs, int line) throws SQLException {
            String string = new String(rs.getString("electiondate"));
            return string;
        }
    }
}

What I want to do is just a unit test of getDates() using EasyMock but I haven't found the way to do it. I'm so confused. Can anybody help me please?

Answer 1

It looks as though getSimpleJdbcTemplate is the biggest problem for unit testing. One way you could test is to extend the class under test and override the getSimpleJdbcTemplate method eg

public class ElectionDaoTest {

    /** Class under test */
    private ElectionsDaoImpl dao;

    @Before
    public void setUp() {
        dao = new ElectionsDaoImpl(){
            SimpleJdbcTemplate getSimpleJdbcTemplate(){
                // Return easy mock version here.
            }
        };
    }

    @Test
    // Do tests
}

There may be an easier way with EasyMock, but I'm not that familiar with it.

Answer 2

Thank you for your comments. I decided to do the test using Spring. My test code ended like this:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations="classpath:beans.xml")
public class DBConectionTest{

    @Resource
    private ElectionsDao electionsDao;

    @Test
    public void testGetDates(){
        List<String> dates = electionsDao.getDates();
        assertNotNull(dates);
    }
}

I'm using the same xml file that I use when running my project. Hope it helps someone.