模拟 RestTemplate.exchange() 方法给出空值答案

【问题标题】：Mocking RestTemplate.exchange() method gives null value模拟 RestTemplate.exchange() 方法给出空值
【发布时间】：2020-09-13 15:00:38
【问题描述】：

模拟 RestTemplate.exchange() 不起作用。 restTemplate.exchange() 模拟的响应在 BDS 适配器类中给出空值。我的测试用例因 BDSAdapter 类中的空指针异常而失败。（response.getStatusCodeValue() 给出空指针异常..Mockito 提示

未使用... -> 在 com..policydetails_adapters.BDSAdapterTest.getInsuranceHoldings(BDSAdapterTest.java:56) [MockitoHint] ...args 好吗？ -> 在 com.policydetails_adapters.BDSAdapter.fetchInsuranceDetails(BDSAdapter.java:77)

 Below are my classes.

测试类：

@RunWith(MockitoJUnitRunner.class)
public class BDSAdapterTest {

    @InjectMocks
    private BDSAdapter bdsAdapter;

    @Mock
    private BDSFetchInsuranceDetailsRequest bdsFetchInsuranceDetailsRequest;

    @Mock
    private RestTemplate restTemplate;

    @Mock
    Environment env;

    @Test
    public void getInsuranceHoldings() throws InsuranceHoldingsException {
        Mockito.when(restTemplate.exchange(
                ArgumentMatchers.anyString(),
                ArgumentMatchers.any(HttpMethod.class),
                ArgumentMatchers.any(),
                ArgumentMatchers.<Class<BDSFetchInsuranceDetailsResponse>>any()))
                             .thenReturn(sampleBDSCustomerInsuranceHoldings());
        BDSFetchInsuranceDetailsResponse bdsFetchInsuranceDetailsResponse = bdsAdapter.fetchInsuranceDetails("MBSG", "S6564318I", "1234", "007");
        assertNotNull("response is not null", bdsFetchInsuranceDetailsResponse);
    }


    public static ResponseEntity<BDSFetchInsuranceDetailsResponse> sampleBDSCustomerInsuranceHoldings() {
        BDSFetchInsuranceDetailsResponse bdsResponse = new BDSFetchInsuranceDetailsResponse();
        Header header = new Header();
        header.setChannelId("MBSG");
        header.setMsgId("4aBE50ZrQtjVuXfTyALJ");
        bdsResponse.setHeader(header);
        ResponseEntity<BDSFetchInsuranceDetailsResponse> response = new ResponseEntity<BDSFetchInsuranceDetailsResponse>(bdsResponse, HttpStatus.ACCEPTED);
        return response;
    }

}

我的实际课程

@组件公共类 BDSAdapter {

@Autowired
RestTemplate restTemplate;

@Autowired
BDSFetchInsuranceDetailsRequest bdsFetchInsuranceDetailsRequest;

@Autowired
Environment env;


public BDSFetchInsuranceDetailsResponse fetchInsuranceDetails(String channelId, String customerId,
        String insurerCode, String policyNumber) throws InsuranceHoldingsException {
    BDSFetchInsuranceDetailsResponse bdsFetchInsuranceDetailsResponse = null;
    try {
        logger.info("Inside BDSAdapter::fetchInsuranceDetails");
        Header header = new Header();
        header.setMsgId(RandomStringUtils.randomAlphanumeric(20));
        header.setChannelId(channelId);
        bdsFetchInsuranceDetailsRequest.setHeader(header);

        HttpHeaders requestHeaders = new HttpHeaders();

        requestHeaders.add("Accept", MediaType.APPLICATION_JSON_VALUE);
        HttpEntity<BDSFetchInsuranceDetailsRequest> requestEntity = new HttpEntity<>(bdsFetchInsuranceDetailsRequest, requestHeaders);

        ResponseEntity<BDSFetchInsuranceDetailsResponse> response = restTemplate.exchange(env.getProperty("bds_fetch_insurance_details_url"),HttpMethod.POST, requestEntity, BDSFetchInsuranceDetailsResponse.class);

        if(response.getStatusCodeValue() == 204) {
            throw new InsuranceHoldingsException(response.getStatusCode().toString(), "No Content");
        }
        bdsFetchInsuranceDetailsResponse = response.getBody();

    } catch (Exception e) {
        e.printStackTrace();
        }
    }
    return bdsFetchInsuranceDetailsResponse;
}

}

【问题讨论】：

标签： spring junit mockito resttemplate

【解决方案1】：

也许，因为 BDSFetchInsuranceDetailsResponse 的模拟将返回的不是 BDSFetchInsuranceDetailsResponse 的类，而是一些模拟类

【讨论】：

【解决方案2】：

restTemplate.exchange() 方法中的参数应该匹配。在此代码中 env.getProperty("bds_fetch_insurance_details_url") 返回与字符串不匹配的 null。所以它给出了空响应。在 When(restTemplate.exchange(-,-,-,-).thenReturn(myResponse) 之前添加了以下语句。它正在工作

`Mockito.when(env.getProperty("bds_fetch_insurance_details_url")).thenReturn("anyString")`;

【讨论】：