如何使用jmockit的Mockups API模拟EntityManager？

Question

我在模拟EntityManager时遇到了问题。一切编译完成后，测试运行，但模拟的方法返回null。

当我在模拟的'find‘方法中设置断点时，应用程序永远不会在那里挂起。我设法用这种方式成功地用静态方法模拟了不同的类--但用这种方法我遇到了问题。

我使用Jmockit 1.7和Java 1.8.0。我试图模拟的类是: javax.persistence.EntityManager

如果需要更多信息，请联系我们。如果有任何帮助，我将非常感激。

下面是我的代码：

@RunWith(JMockit.class)
public class ShapefileSerializerTest {

    @Mocked
    private EntityManager em;

    @BeforeClass
    public static void setUpBeforeClass() throws Exception {
        new MockDatabase();
    }

    @Test
    public void testPrepareShapefile() {
        String[][] data = new String[][] {{"1", "100"}, {"1", "101"}, {"1", "102"}, {"1", "103"}, {"2", "200"}, {"2", "201"}};

        List<Map<String, String>> featuresData = Stream.of(data).map(row -> {
            Map<String, String> map = new HashMap<>(2);
            map.put("layerId", row[0]);
            map.put("id", row[1]);
            return map;
        }).collect(Collectors.toList());

        ShapefileSerializer shapefileSerializer = new ShapefileSerializer("shapefiles");
        // if I do not set up the em here - then it will be null inside the tested class
        Deencapsulation.setField(shapefileSerializer, em);

        Response response = shapefileSerializer.prepareShapefile(featuresData);

        assertEquals(Status.OK.getStatusCode(), response.getStatus());
    } 

    public static final class MockDatabase extends MockUp<EntityManager> {
        @Mock
        @SuppressWarnings("unchecked")
        public <T> T find(Class<T> entityClass, Object primaryKey) {
            return (T) new ProjectLayer();
        }
    }
}

Answer 1

将JMockit升级到1.8版或更高版本，并将测试类更改为以下内容：

@RunWith(JMockit.class)
public class ShapefileSerializerTest {
    @Mocked EntityManager em;

    @Test
    public void testPrepareShapefile() {
        String[][] data = ...
        List<Map<String, String>> featuresData = ...

        ShapefileSerializer shapefileSerializer = new ShapefileSerializer("shapefiles");
        Deencapsulation.setField(shapefileSerializer, em);

        new Expectations() {{
            em.find((Class<?>) any, any); result = new ProjectLayer();
        }};

        Response response = shapefileSerializer.prepareShapefile(featuresData);

        assertEquals(Status.OK.getStatusCode(), response.getStatus());
    } 
}