Question

我正在和Mockito一起使用Junit。我想测试EntityManager，我得到java.lang.NullPointerException

以下是我的尝试，主类方法是，

@Override
    public ReplicationPerspective buildReplicationPerspective(final String replicationDomain)
        throws ReplicationStateException {
        try {
            System.out.println("Test");
            final ReplicationPerspective localPerspective =
                this.replicationPerspectiveQuery.findReplicationPerspective(replicationDomain);

            List<String> ncdKeys = new ArrayList<String>();
            for (NodeChangeDelta ncd : this.nodeChangeDeltaQuery.findByChangeStatus(
                replicationDomain, ChangeStatus.PENDING)) {
                ncdKeys.add(ncd.getKey());
            }
            localPerspective.setPendingNodeChangeDeltaKeys(ncdKeys);

            LOGGER.debug("Local perspective is {} ", localPerspective);
            return localPerspective;
        }
        catch (Throwable t) {
            LOGGER.error("Failed to build replication perspective", t);
            throw new ReplicationStateException(t);
        }
    }

replicationPerspectiveQuery Bean文件方法是，

@PersistenceContext
    private EntityManager em;

@Override
    public ReplicationPerspective findReplicationPerspective(final String replicationDomain) {
        Validate.notBlank(replicationDomain);

        ReplicationPerspective perspective =
            this.em.find(ReplicationPerspective.class, replicationDomain);
        if (perspective == null) {
            this.replicationPerspectiveInitializer
                .initializeReplicationPerspective(replicationDomain);
            perspective = this.em.find(ReplicationPerspective.class, replicationDomain);
        }

        return perspective;
    }

我的测试用例方法是，

@Test
    public void testBuildReplicationPerspective() throws ReplicationStateException {
            this.replicationStateServiceBean =
                new ReplicationStateServiceBean(null, null, null, null,
                    new ReplicationPerspectiveQueryBean(), null, null);

            this.em = Mockito.mock(EntityManager.class);
            Mockito.when(this.em.find(ReplicationPerspective.class, REPLICATION_DOMAIN))
                .thenReturn(null);

            this.replicationStateServiceBean.buildReplicationPerspective(REPLICATION_DOMAIN);
    }

我在下面一行的replicationPerspectiveQuery Bean文件中遇到NPE错误

ReplicationPerspective perspective =
            this.em.find(ReplicationPerspective.class, replicationDomain);

如何测试实体经理，帮我解决。

我也试过像下面那样嘲笑但是没有用，

Mockito.when(this.replicationPerspectiveQuery.findReplicationPerspective(REPLICATION_DOMAIN)).thenReturn(null);

Answer 1

你缺乏让Mockito进行实际注射的指示。现在你已经模拟了EntityManager，但它没有在任何地方使用。

您可以将bean声明为测试类的成员，并使用@InjectMocks对其进行注释，让Mockito为您进行布线。

有关更多信息和示例，另请参阅the documentation。

使用JUnit Mockito测试EntityManager

1 个答案: