Question

我想用这个单元测试我的DAO实现：

public class BaseDAOImplTest {

    private EntityManagerFactory emFactory;
    private EntityManager em;
    private static Logger logger = Logger.getLogger(BaseDAOImplTest.class
            .getName());

    @Before
    public void setUp() throws SQLException, ClassNotFoundException {

        logger.info("Starting in-memory database for unit tests");

        try {

            //Creating testDB database
            Class.forName("org.apache.derby.jdbc.EmbeddedDriver");
            DriverManager.getConnection("jdbc:derby:memory:TestingDB;create=true");
            logger.info("Building JPA EntityManager for unit tests");

            //Creating Entity Manager
            emFactory = Persistence.createEntityManagerFactory("TestingDB");
            em = emFactory.createEntityManager();
        } catch (ClassNotFoundException e) {

            e.printStackTrace();
        }
    }

    @Test
    public void testPersistExcursion() {
        BaseDAOImpl baseDao = new BaseDAOImpl(Excursion.class, em);
        Calendar c = Calendar.getInstance();
        c.set(2013, 8, 24);
        Excursion ex1 = createExcursion(c.getTime(), 10, "Simple excursion 1", "New York", 35);
        ex1 = baseDao.persist(ex1);
        assertEquals(baseDao.findById(ex1.getId()), ex1);
    }

    @Test
    public void testPersist() {
        try {
            Class.forName("org.apache.derby.jdbc.EmbeddedDriver");
            String dbURL = "jdbc:derby:memory:TestingDB;create=true";
            Connection conn = getConnection(dbURL);
            EntityManagerFactory f = Persistence.createEntityManagerFactory("TestingDB");
            EntityManager em = f.createEntityManager();
            BaseDAOImpl b = new BaseDAOImpl(Excursion.class, em);
            Calendar c = Calendar.getInstance();
            c.set(2013, 8, 24);
            Excursion ex1 = createExcursion(c.getTime(), 10, "Simple excursion 1", "New York", 35);
            ex1 = b.persist(ex1);
            assertEquals(b.findById(ex1.getId()), ex1);
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(BaseDAOImplTest.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}

testPersist正在运行，结果是此测试通过了。但是在testPersistExcursion中，我在NullPointerException时收到错误，因为在setUp我得到了：

java.lang.ClassNotFoundException: org.apache.derby.jdbc.EmbeddedDriver

我只是想将EntityManager添加为全局并在setUp初始化，所以我不需要在每个单元测试中再次编写这些行（我在一些文章中看到它并且我认为它很好的形式给出）。但这有什么问题呢？为什么它在单元测试中工作但在setUp我找不到那个驱动程序？感谢

修改

我发现问题，那是在maven。我有错误的artifactId。但是现在我在"Unable to build EntityManagerFactory" <{1}}处遇到问题：emFactory = Persistence.createEntityManagerFactory("TestingDB");

我的持久单位：

<persistence-unit name="TestingDB" transaction-type="RESOURCE_LOCAL">
    <class>cz.infi.javatravelagency.entities.Reservation</class>
    <class>cz.infi.javatravelagency.entities.Trip</class>
    <class>cz.infi.javatravelagency.entities.Customer</class>
    <class>cz.infi.javatravelagency.entities.Excursion</class>
    <exclude-unlisted-classes>false</exclude-unlisted-classes>
    <properties>
      <property name="hibernate.connection.username" value="APP"/>
      <property name="hibernate.connection.driver" value="org.apache.derby.jdbc.EmbeddedDriver"/>
      <property name="hibernate.connection.password" value="APP"/>
      <property name="hibernate.connection.url" value="jdbc:derby:memory:TestingDB;create=true"/>
      <property name="hibernate.connection.autoReconnect" value="true" />  
      <property name="hibernate.connection.autoReconnectForPools" value="true" />  
      <property name="hibernate.dialect" value="org.hibernate.dialect.DerbyDialect" />  
    </properties>
  </persistence-unit>

Answer 1

好的，继续我的评论，我已经尝试了这个，它按预期工作。运行测试时，src / test / resources / META-INF中的测试特定persistence.xml将按预期获取。

然后，您可以创建一个BaseDao类，其长度如下：

public class BaseDao {

    private static EntityManagerFactory emf;

    public static EntityManager getEntityManager() {

        if (emf == null) {

            emf = Persistence.createEntityManagerFactory("test");
        }

        return emf.createEntityManager();
    }
}

}

哪个好多了！

单元测试数据库层DAO与内存中的derby

1 个答案: