java - 如何模拟 REST 模板交换？

Question

我有一项服务，我需要通过 rest 向外部服务器询问一些信息:

public class SomeService {

    public List<ObjectA> getListofObjectsA() {
        List<ObjectA> objectAList = new ArrayList<ObjectA>();
        ParameterizedTypeReference<List<ObjectA>> typeRef = new ParameterizedTypeReference<List<ObjectA>>() {};
        ResponseEntity<List<ObjectA>> responseEntity = restTemplate.exchange("/objects/get-objectA", HttpMethod.POST, new HttpEntity<>(ObjectAList), typeRef);
        return responseEntity.getBody();
    }
}

如何为 getListofObjectsA() 编写 JUnit 测试？

我尝试过以下方法:

@RunWith(MockitoJUnitRunner.class)
public class SomeServiceTest {
    private MockRestServiceServer mockServer;

    @Mock
    private RestTemplate restTemplate;

    @Inject
   private SomeService underTest;

@Before
public void setup() {
    mockServer = MockRestServiceServer.createServer(restTemplate);
    underTest = new SomeService(restTemplate);
    mockServer.expect(requestTo("/objects/get-objectA")).andExpect(method(HttpMethod.POST))
            .andRespond(withSuccess("{json list response}", MediaType.APPLICATION_JSON));
}

    @Test
    public void testGetObjectAList() {
    List<ObjectA> res = underTest.getListofObjectsA();
    Assert.assertEquals(myobjectA, res.get(0));
}

但是上面的代码不起作用，它表明 responseEntitty 是 null。如何更正我的测试以正确模拟 restTemplate.exchange？

Answer 1

您不需要 MockRestServiceServer 对象。注释是 @InjectMocks 而不是 @Inject。下面是一个应该可以工作的示例代码

@RunWith(MockitoJUnitRunner.class)
public class SomeServiceTest {
    @Mock
    private RestTemplate restTemplate;

    @InjectMocks
    private SomeService underTest;

    @Test
    public void testGetObjectAList() {
        ObjectA myobjectA = new ObjectA();
        //define the entity you want the exchange to return
        ResponseEntity<List<ObjectA>> myEntity = new ResponseEntity<List<ObjectA>>(HttpStatus.ACCEPTED);
        Mockito.when(restTemplate.exchange(
            Matchers.eq("/objects/get-objectA"),
            Matchers.eq(HttpMethod.POST),
            Matchers.<HttpEntity<List<ObjectA>>>any(),
            Matchers.<ParameterizedTypeReference<List<ObjectA>>>any())
        ).thenReturn(myEntity);

        List<ObjectA> res = underTest.getListofObjectsA();
        Assert.assertEquals(myobjectA, res.get(0));
    }