如何模拟REST模板交换？

Question

我有一项服务,我需要通过休息询问外部服务器以获取一些信息:

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();
    }
}

我该如何编写JUnit测试getListofObjectsA()？

我试过以下:

@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,那就说明responseEntitty是null.如何正确模拟我的测试restTemplate.exchange？

Answer 1

你不需要MockRestServiceServer对象.注释@InjectMocks不是@Inject.下面是一个应该有效的示例代码

@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));
    }

Answer 2

ResponseEntity<String> responseEntity = new ResponseEntity<String>("sampleBodyString", HttpStatus.ACCEPTED);
when(restTemplate.exchange(
                           Matchers.anyString(), 
                           Matchers.any(HttpMethod.class),
                           Matchers.<HttpEntity<?>> any(), 
                           Matchers.<Class<String>> any()
                          )
                         ).thenReturn(responseEntity);

Answer 3

这是未处理的ArgumentMatchers类的示例

when(restTemplate.exchange(
                ArgumentMatchers.anyString(),
                ArgumentMatchers.any(HttpMethod.class),
                ArgumentMatchers.any(),
                ArgumentMatchers.<Class<String>>any()))
             .thenReturn(responseEntity);

Answer 4

对我来说，我必须使用Matchers.any（URI.class）

Mockito.when(restTemplate.exchange(Matchers.any(URI.class), Matchers.any(HttpMethod.class), Matchers.<HttpEntity<?>> any(), Matchers.<Class<Object>> any())).thenReturn(myEntity);

Answer 5

这项工作在我这边。

ResourceBean resourceBean = initResourceBean();
ResponseEntity<ResourceBean> responseEntity  
    = new ResponseEntity<ResourceBean>(resourceBean, HttpStatus.ACCEPTED);
when(restTemplate.exchange(
    Matchers.anyObject(), 
    Matchers.any(HttpMethod.class),
    Matchers.<HttpEntity> any(), 
    Matchers.<Class<ResourceBean>> any())
 ).thenReturn(responseEntity);