如何模拟 RestTemplate 交换？

Question

我想对assignApplicationsToUser 进行单元测试。给出了 applicationId 和用户 ID 的列表，并且我有一个 URL 来验证用户。我遇到了下面提到的异常。

java.lang.NullPointerException: Cannot invoke "com.fasterxml.jackson.databind.JsonNode.asText()" because the return value of "com.fasterxml.jackson.databind.JsonNode.get(String)" is null

AssignmentService.java

public class AssignmentService implements AssignemetServiceInterface {
    @Autowired
    AppInterceptor appInterceptor;
    @Autowired
    AssignmentRepository assignmentRepository;
    @Autowired
    private RestTemplate restTemplate;
    private String uri="http://localhost:8080/api/users/"+uuid;

    @Override
    public List<String> assignApplicationsToUser(List<String> applications, String uuid)
            throws SQLException, RequestEntityNotFoundException {

        HttpHeaders headers = new HttpHeaders();
        headers.set("token", appInterceptor.getLoggedInUser());
        HttpEntity<String> requestEntity = new HttpEntity<>(null, headers);
        String result = restTemplate.exchange(uri, HttpMethod.GET, requestEntity, String.class).getBody();

        ObjectMapper objectMapper = new ObjectMapper();
        List<String> response = new ArrayList<>();
        JsonNode responseJson = objectMapper.readTree(result);
        if (responseJson.get("data") == null
                    && responseJson.get("error").get("status").asText().equals("NOT_FOUND")) {
                throw new RequestEntityNotFoundException(uuid, "find");
        }

        for (String application : applications) {
        ApplicationAssignment isAssigned = assignmentRepository.findOneByApplicationId(application);
            if (isAssigned != null) {
                isAssigned.setIsUser(true);
                response.add(application + " reassigned to "+ uuid);
                isAssigned.setAssignedTo(uuid);
                this.assignmentRepository.save(isAssigned);
                } 
           else {
          ApplicationAssignment newApplication = new ApplicationAssignment(application, uuid, true);
    
            this.assignmentRepository.save(newApplication);
            response.add(application + " assigned successfully");
        }
       }
    return response;
}
}

样本输入： { 应用程序：["APP001","APP002","APP003","APP004"], uuid：“用户1” }

已编辑： 我已经添加了相同的示例响应。

{
    "data": {
        "id": "fa727274-5a74-428a-b0f6-501eebafd8e8",
        "name": "Akash",
        "email": "AkashTyagi@fico.com",
        "phone": 8799190991,
        "isActive": true,
        "createdBy": "abhishekjaiswal@fico.com",
        "updatedBy": null,
        "creationTimeStamp": "2021-08-11T11:23:05.356+00:00",
        "updationTimeStamp": null
    },
    "error": null,
    "timeStamp": "2021-08-16T05:02:04.866+00:00",
    "success": true
}

AssignmentServiceTest.java

@RunWith(MockitoJUnitRunner.class)
@SpringBootTest
public class AssignmentServiceTest {

    private static final Logger LOGGER = LoggerFactory.getLogger(AssignmentServiceTest.class);
    @InjectMocks
    private AssignmentService assignmentService;
    
    @Mock
    private AssignmentRepository assignmentRepo;
    
    @Mock
    private AppInterceptor appInterceptor;
    
    @Mock
    private RestTemplate restTemplate;
    
    ObjectMapper  objectMapper;
    String jsonString="{\r\n"
            + "    \"data\": {\r\n"
            + "        \"id\": \"fa727274-5a74-428a-b0f6-501eebafd8e8\",\r\n"
            + "        \"name\": \"Akash\",\r\n"
            + "        \"email\": \"AkashTyagi@fico.com\",\r\n"
            + "        \"phone\": 8799190991,\r\n"
            + "        \"isActive\": true,\r\n"
            + "        \"createdBy\": \"abhishekjaiswal@fico.com\",\r\n"
            + "        \"updatedBy\": null,\r\n"
            + "        \"creationTimeStamp\": \"2021-08-11T11:23:05.356+00:00\",\r\n"
            + "        \"updationTimeStamp\": null\r\n"
            + "    },\r\n"
            + "    \"error\": null,\r\n"
            + "    \"timeStamp\": \"2021-08-16T05:02:04.866+00:00\",\r\n"
            + "    \"success\": true\r\n"
            + "}";;
            
    JsonNode mock;
    
    @BeforeEach
    private void setUp() throws JsonMappingException, JsonProcessingException {
    
         objectMapper = new ObjectMapper();
         mock = org.mockito.Mockito.mock(JsonNode.class);
    }
    @Test
    public void test_assignApplicationsToUser() throws NullPointerException, SQLException, RequestEntityNotFoundException, IndexOutOfBoundsException,JsonProcessingException, URISyntaxException{

        LOGGER.info("Begin of test_assignApplicationToUser method");

        
        ApplicationAssignment applicationAssignment = new ApplicationAssignment("1","u1",true);
        ApplicationAssignment savedApplicationAssignment = new ApplicationAssignment("1","u2",true);
    

        ResponseEntity<String> myEntity = new ResponseEntity<String>("{\r\"error\":null\r}",HttpStatus.ACCEPTED);
        
        
        Mockito.when(restTemplate.exchange(
                ArgumentMatchers.anyString(),
                ArgumentMatchers.any(HttpMethod.class),
                ArgumentMatchers.any(),
                ArgumentMatchers.<Class<String>>any())).thenReturn(myEntity);
        
        Mockito.when(appInterceptor.getLoggedInUser()).thenReturn("abhishek@fico.com");

     
        Mockito.when(mock.get("data")).thenReturn(mock);
        Mockito.when(mock.get("error")).thenReturn(mock);
        Mockito.when(mock.get("error").asText()).thenReturn("FOUND");
        LOGGER.info("Node value "+ mock.asText());
        
        Mockito.when(assignmentRepo.findOneByApplicationId("1")).thenReturn(applicationAssignment);
        Mockito.when(assignmentRepo.save(ArgumentMatchers.any())).thenReturn(savedApplicationAssignment);
 
        // Mock the input List of applications
        List<String> listOfApplication = new ArrayList<>();
        listOfApplication.add("app1");
        listOfApplication.add("app2");
        List<String> response = assignmentService.assignApplicationsToUser(listOfApplication,"u1");
        assertEquals(response.get(0),"app1 assigned successfully");
    }
}

Answer 1

在主代码中，创建两个 pojo，如下所示，代表其余调用的响应。

@JsonIgnoreProperties(ignoreUnknown = true)
public class UserDataResponse {

    @JsonProperty("data")
    UserInfo userInfo;

    @JsonProperty("error")
    String error;

    @JsonProperty("success")
    boolean success;


}

@JsonIgnoreProperties(ignoreUnknown = true)
public class UserInfo {

    @JsonProperty("id")
    String id;

    @JsonProperty("name")
    String name;

    @JsonProperty("email")
    String email;

    @JsonProperty("phone")
    String phone;

    @JsonProperty("isActive")
    boolean isActive;

    @JsonProperty("createdBy")
    String createdBy;

    @JsonProperty("updatedBy")
    String updatedBy;
}

在 AssignmentService 类中更改您的代码以获取如下响应，因为这是基于 HttpStatus 代码处理其余响应的更好方法，而不是尝试在 json 中添加元素。所以你的主要休息电话如下所示：

        String result = restTemplate.exchange(uri, HttpMethod.GET, requestEntity, String.class);

        if(result.getStatusCode()==HttpStatus.OK){
            UserDataResponse userDataResponse = readResponse(result,UserDataResponse.class);
            
        }else if(result.getStatusCode()==HttpStatus.NOT_FOUND){
            throw new RequestEntityNotFoundException(uuid, "find");
        }

// You can make below code as part of the helper class and use it anywhere you want.
      private <T> T readResponse(ResponseEntity<String> responseEntity,Class<T> classType){
        T object;
        try {
                object = objectMapper.readValue(responseEntity.getBody(),classType);
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        return null;
    }

测试代码： 将 AppInterceptor、repository 和 resttemplate 等服务的所有变量模拟为注入到 AssignmentService。 将以下所有代码放在 AssingmentServiceTest 等测试类中

    @Mock
    AppInterceptor appInterceptor;

    @Mock
    AssignmentRepository assignmentRepository;

    @Mock
    RestTemplate restTemplate;

    @InjectMocks
    AssignmentService assignmentService;

    ObjectMapper objectMapper = new ObjectMapper();

    @Test
    public void test_assignApplicationsToUser(){

        UserDataResponse restResponse = new UserDataResponse();
        String jsonString="{\r\n"
                + "    \"data\": {\r\n"
                + "        \"id\": \"fa727274-5a74-428a-b0f6-501eebafd8e8\",\r\n"
                + "        \"name\": \"Akash\",\r\n"
                + "        \"email\": \"AkashTyagi@fico.com\",\r\n"
                + "        \"phone\": 8799190991,\r\n"
                + "        \"isActive\": true,\r\n"
                + "        \"createdBy\": \"abhishekjaiswal@fico.com\",\r\n"
                + "        \"updatedBy\": null,\r\n"
                + "        \"creationTimeStamp\": \"2021-08-11T11:23:05.356+00:00\",\r\n"
                + "        \"updationTimeStamp\": null\r\n"
                + "    },\r\n"
                + "    \"error\": null,\r\n"
                + "    \"timeStamp\": \"2021-08-16T05:02:04.866+00:00\",\r\n"
                + "    \"success\": true\r\n"
                + "}";

        restResponse = readResponse(jsonString, UserDataResponse.class);
        ResponseEntity<String> myEntity = new ResponseEntity<String>(restResponse.toString(),HttpStatus.OK);
        Mockito.when(resttemplate.exchange(
                ArgumentMatchers.anyString(),
                ArgumentMatchers.any(HttpMethod.class),
                ArgumentMatchers.any(),
                ArgumentMatchers.<Class<String>>any())
    ).thenReturn(myEntity);

        // You can create a ApplicationAssignment pojo and pass it in thenReturn
        ApplicationAssignment applicationAssignment = new ApplicationAssingment(1,"sd");
        Mockito.when(assignmentRepository.findOneByApplicationId(ArgumentMatchers.any())).thenReturn(assignmentRepository);

        Mockito.when(appInterceptor.getLoggedInUser).thenReturn("token");

        // You can mock the response here but looks like that response is not used anywhere
        ApplicationAssignment savedApplicationAssignment = new ApplicationAssignment(1,"ss");
        Mockito.when(assignmentRepository.save(ArgumentMatchers.any())).thenReturn(savedApplicationAssignment);

        // Mock the input List of applications
        List<String> listOfApplication = new ArrayList<>();
        listOfApplication.add("app1");
        listOfApplication.add("app2");
        List<String> response = assignmentService.assignApplicationsToUser(listOfApplication,"1212");
        assertEquals(response[0],"app1 reassigned to 1212");
  }