在Junit中模拟嵌套对象

Question

我有一个服务我是这样嘲笑的：

@ExtendWith(MockitoExtension.class)
class MyServiceTest {

@InjectMocks
MyService myService;



    @Test
    void testSendRec() {
       myService.sendDocRec(.. pass params..);
    }

}

服务：

@Service
public class MyService {

    String sendDocRec( params ) {

       // builds request
       HttpUriRequestBase request = getRequest(  params );

        String response = doRequest(request);
    }

    public String doRequest(ClassicHttpRequest request) {
    String result = null;

        try (CloseableHttpClient httpclient = HttpClients.custom()
                .setConnectionManager(this.connectionManager)
                .setConnectionManagerShared(true) 
                .setDefaultRequestConfig(this.requestConfig)
                .build()) {

            final HttpClientContext clientContext = HttpClientContext.create();

            try (CloseableHttpResponse response = httpclient.execute(request, clientContext)) {

                result = EntityUtils.toString(response.getEntity());
            
            }
        } catch (URISyntaxException e) {
            log.error("Invalid URI {}", e);
        } catch (IOException e) {
            log.error("Failed to make HTTP Request {}", e);
        } catch (ParseException e) {
            log.error("Failed parsing response body {}", e);
        }

        return result;
    }

}

我需要能够模拟“CloseableHttpResponse Response = http client . execute(request，clientContext)”，这样“response”对象就是我提前创建的。我希望一些嘲讽的when/then构造可以解决这个问题。我会很感激如何做到这一点的想法。谢谢！

Answer 1

用现在的代码结构是做不到的。正在测试的方法中创建httpclient对象。所以不能被嘲讽。

您需要将 httpclient 对象创建委托给另一个属于不同类（类似于 HttpClientFactory 类）的方法。该 HttpClientFactory 类应该只负责创建 httpClient 实例。如果需要，可以为类编写单独的单元测试用例。

 @Inject
 private HttpClientFactory httpClientFactory;

      public String doRequest(ClassicHttpRequest request) {
        String result = null;
    
            try (CloseableHttpClient httpclient = httpClientFactory.getInstance()) {
    
                final HttpClientContext clientContext = HttpClientContext.create();
    
                try (CloseableHttpResponse response = httpclient.execute(request, clientContext)) {
    
                    result = EntityUtils.toString(response.getEntity());
                
                }
            } catch (URISyntaxException e) {
                log.error("Invalid URI {}", e);
            } catch (IOException e) {
                log.error("Failed to make HTTP Request {}", e);
            } catch (ParseException e) {
                log.error("Failed parsing response body {}", e);
            }
    
            return result;
        }

现在，您可以模拟如下响应:

 @Mock
 private HttpClientFactory httpClientFactory;

public String testDoRequest(ClassicHttpRequest request) {
....
    CloseableHttpClient mockedClient = mock(CloseableHttpClient.class);
    CloseableHttpResponse mockedResponse = mock(CloseableHttpResponse.class);
    when(httpClientFactory.getInstance()).thenReturn(mockedClient);
    when(mockedClient.execute(eq(request), any(clientContext))).thenReturn(mockedResponse);
....}