JUnit＆Mockito：如何将字段值注入Spring组件？

Question

I'm trying to test Spring @Repository component but first I've to inject table name to let this work properly.

Here's what I made. It's simple DAO:

@Repository
@Transactional
public class AccountDAO {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    private String table = "accounts"; <-- I need to inject this value from tests
    ...
}

the unit test:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:spring-web-servlet.xml")
@Transactional
public class AccountDaoTest {

    @Autowired
    private AccountDAO accountDAO;

    @Before
    public void init() {
        accountDAO = Mockito.spy(accountDAO);
        ReflectionTestUtils.setField(accountDAO, "table", "accounts_test");
    }

    ...
}

The problem is that ReflectionTestUtils ignores field assignment and accountDAO still uses accounts table name value instead of accounts_test .

How can I round this problem?

Answer 1

You can use two techniques to change the table name stored in private variable:

1. ReflectionTestUtils without mockito spying.
2. Use Mockito's annotations @Spy and @InjectMocks

But this is not very reliable integration testing, because when somebody changes table schema, your test wouldn't catch the problem. There are ways how to tackle such problem:

1. If your application executes delta-scripts to migrate DB schema and metadata to latest version (eg by using Liquibase or FlyWay), you can recreate DB schema in-memery/embedded database (eg H2, HSQL) during test and run test against against original table. This is modern approach.
2. If your company architecture is old fashioned, where some DBAs execute SQL delta scripts independently on your app deployment, there has to be some DEV DB environment. Use that environment for your integration testing. You can tidy up/prepare your table for testing upfront.

Answer 2

Here, your want to separate real database and integration test database. Your goal is to test that DAO layer works well. I suggest to remove completely Mockito and use DBUnit for instance.

Then, you keep your DAO, Spring an JUnit. Injecting another table name is not necessary.

DBUnit allows you to create a small database only used for testing according to a XML dataset.

Something like this:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {PersistenceContext.class})
@TestExecutionListeners({ DependencyInjectionTestExecutionListener.class,
    DirtiesContextTestExecutionListener.class,
    TransactionalTestExecutionListener.class,
    DbUnitTestExecutionListener.class })
@DatabaseSetup("my-dbunit-dataset.xml")
public class AccountDAOTest {

    @Autowired
    private AccountDAO accountDAO;

    @Test
    public void findAllAccounts() {
        assertThat(accountDAO.findAll().size(), is(2));
    }
}

my-dbunit-dataset.xml :

<dataset>
    <account id="1" value1="foo" />
    <account id="2" value1="bar" />
</dataset>

DBunit is really powerfull. You can find the official link here :

http://dbunit.sourceforge.net/howto.html DbUnit - Getting started

Answer 3

You can also define a setter method for table field:

protected void setTable(String pTableName) this.table = pTableName; }

and invoke the setter in the test class before() method.