JUNIT 测试中未创建 Hibernate 事务

Question

Initially, the data was not being committed to the database immediately upon the change in the frontend. The transaction was never created and committed, which is why I have added the transaction part to the code. It works well now but when I test the same method after writing the transaction part one of the test cases fail throwing NPE( null pointer exception) while the remaining test cases which use the same method pass. I am a Rookie at Spring Hibernate, Trying to understand the reason behind the failure.

DummyDAO.java

public void remove(final int roleId, final int round, final int gameId)
    {
        Preconditions.checkArgument(roleId > 0, INVALID_ROLEID);
        Preconditions.checkArgument(round > 0, INVALID_ROUND);
        Preconditions.checkArgument(gameId > 0, INVALID_GAMEID);
        Session session = factory.openSession();
        final Transaction transaction = session.beginTransaction();
        try
        {
            Query query = session.getNamedQuery(REMOVE);
            query.setParameter(ROLE_ID, roleId);
            query.setParameter(ROUND, round);
            query.setParameter(GAME_ID, gameId);
            query.executeUpdate();
            transaction.commit();
        }
        finally
        {
            session.close();
        }
    }

In the below-mentioned test cases, the first test case fails throwing a null pointer exception at transaction.commit() in the dao method. When I debug the test case, I see that the transaction has a null value. Not sure why the transaction is not getting created. The second Test case runs well.

DummyDAOTest.java

@Test
    public void remove_getNamedQueryValidName_NoError()
    {
        final ArgumentCaptor<String> argumentCaptor = ArgumentCaptor
                .forClass(String.class);
        roleQuestionRoundDAO.remove(ROLE_ID_ONE, ROUND_ONE, GAME_ID_ONE);
        verify(session).getNamedQuery(argumentCaptor.capture());
        assertEquals(RoleQuestionRoundDAO.REMOVE, argumentCaptor.getValue());
    }

@Test
    public void remove_roleId_SetParameterFails()
    {
        doThrow(HibernateException.class).when(queryMocked).setParameter(eq("roleId"), eq(ROLE_ID_ONE));
        expectedException.expect(HibernateException.class);
        roleQuestionRoundDAO.remove(ROLE_ID_ONE, ROUND_ONE, GAME_ID_ONE);
    }

StackTrace (console)

java.lang.NullPointerException
    at dummy.model.RoleQuestionRoundDAO.remove(RoleQuestionRoundDAO.java:288)
    at dummy.model.RoleQuestionRoundDAOTest.remove_getNamedQueryValidName_NoError(RoleQuestionRoundDAOTest.java:790)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
    at org.junit.rules.ExpectedException$ExpectedExceptionStatement.evaluate(ExpectedException.java:239)
    at org.junit.rules.RunRules.evaluate(RunRules.java:20)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:539)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:761)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:461)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:207)

QUERY:

<query name="remove">
        <![CDATA[update RoleQuestionRound rq set rq.activeInd = 0 where rq.roleQuestionRoundComposite.round = :round and rq.roleQuestionRoundComposite.roleId = :roleId and rq.roleQuestionRoundComposite.gameId = :gameId]]>
    </query>

Answer 1

If I use a catch block to catch the Null Pointer Exception then the test cases passes. I am not sure why would I have to catch the exception which is not being thrown at all, wrt other test cases.