java - 如何测试 EntityManager.persist() 调用

Question

我在 Spring 容器中进行了一个简单的测试:

public class JpaCategoryRepositoryTest extends AbstractJpaJavaTestBase {

    @Inject
    private CategoryService categoryService;

    @Test
    public void testStoreCategory(){
        final Category category = new CategoryBuilder()
                .name("Test category")
                .build();
        assertEquals("Cateogory ID is not assigned", 0L, category.getId());
        categoryService.storeCategory(category);
        assertNotEquals("Category ID is persistent", 0L, category.getId());
    }
}

assertNotEquals 失败。我以为交易还没有提交。好的，我已经更新了测试，添加了事务管理:

public class JpaCategoryRepositoryTest extends AbstractJpaJavaTestBase {

    @Inject
    private CategoryService categoryService;

    @Inject
    TransactionTemplate transactionTemplate;

    @Test
    public void testStoreCategory(){
        final Category category = new CategoryBuilder()
                .name("Test category")
                .build();
        assertEquals("Cateogory ID is not assigned", 0L, category.getId());
        transactionTemplate.execute(new TransactionCallback<Void>() {
            @Override
            public Void doInTransaction(TransactionStatus status) {
                categoryService.storeCategory(category);
                return null;
            }
        });
        assertNotEquals("Category ID is persistent", 0L, category.getId());
    }
}

但这并没有帮助。在集成测试期间测试实体已保存的最佳模式是什么？当我在测试失败后检查表时，实际的实体被保存。

Answer 1

在 JPA 规范中，何时准确设置实体的 ID 取决于 JPA 实现。但是，必须在将实体写入数据库时​​设置它。您可以通过调用entityManager.flush()来强制执行此操作。因此，将一个entityManager添加到您的测试中:

@PersistenceContext
private EntityManager entityManager;

并在存储实体后调用flush():

categoryService.storeCategory(category);
entityManager.flush();

应该修复你的测试。

另请参阅:When does the JPA set a @GeneratedValue @Id