单元测试给出NullPointerException

如何解决单元测试给出NullPointerException

我正在尝试为handler编写一个单元测试用例。功能。但是，它返回空指针异常。 当我在单元测试中打印请求对象时，它返回null。但是，我已经初始化了请求对象，但不确定为什么它给出了空指针异常。数据对象有问题吗？我错过了什么吗？有人可以帮忙吗？谢谢！

public class ServicesHandlerTest {

    @Mock
    private RestTemplate restTemplate;

    @Mock
    private ObjectMapper mapper;

    @Mock
    private AuthHandler AuthHandler;

    @InjectMocks
    ServicesHandler handler;

    @Before
    public void init() {
        MockitoAnnotations.initMocks(this);
    }

    @After
    public void tearDown() throws Exception {
    }

    @Test
    public void testSuccess() throws Exception {
        Data data = new Data();
        data.setRequestId(UUID.randomUUID().toString());  
        data.setRequestedQuantity(10);

        Request request = new Request();
        request.setData(data );

        System.out.println("request = " + request);
        ServicesHandler handler = new ServicesHandler();
        Mockito.when(AuthHandler.requestToken()).thenReturn("randomString");
Mockito.when(msAuthHandler.createAuthorizationBearerHttpHeaders("randomString")).thenReturn(any());
        Mockito.when(restTemplate.postForEntity(anyString(),any(),eq(String.class))).thenReturn(new ResponseEntity<String>(HttpStatus.OK));
        handler.sendRequest(request);
    }

 @Component
 public class ServicesHandler extends AbstractHandler {

    @Value("${api.host}")
    private String msApiHost;

    @Value("${base.path}")
    private String BasePath;

    @Autowired
    private AuthHandler authHandler;

    public AuthHandler getAuthHandler() {
        return authHandler;
    }



   public ResponseEntity<String> sendRequest(Request pr) throws Exception {
    
   ResponseEntity<String> response = null;

        try {
            String requestToken = getAuthHandler().requestToken();

            HttpHeaders headers = getAuthHandler().createAuthorizationBearerHttpHeaders(requestToken);
            
            String apiUrl = ApiHost + BasePath;

            RestTemplate restTemplate = new RestTemplate();
            MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter = new MappingJackson2HttpMessageConverter();
            ObjectMapper objectMapper = new ObjectMapper();
            objectMapper.setSerializationInclusion(Include.NON_NULL);
            mappingJackson2HttpMessageConverter.setobjectMapper(objectMapper);
            restTemplate.getMessageConverters().add(mappingJackson2HttpMessageConverter);

        httpentity<Request> request = new httpentity<Request>(pr,headers);
            response = restTemplate.postForEntity(apiUrl,request,String.class);
        } catch (HttpStatusCodeException e) {
            logger.error("Error when sending for provisioning " + e.getResponseBodyAsstring(),e);
            return ResponseEntity.status(e.getStatusCode()).body(e.getResponseBodyAsstring());
        } catch (Exception e) {
            throw e;
        }

        return response;
   }
 }

public class Data {
    private String requestId;
    private Integer requestedQuantity;

    public String getRequestId() {
        return requestId;
    }

    public void setRequestId(String requestId) {
        this.requestId = requestId;
    }

    public Integer getRequestedQuantity() {
        return requestedQuantity;
    }

    public void setRequestedQuantity(Integer requestedQuantity) {
        this.requestedQuantity = requestedQuantity;
    }
}

在getAuthHandler().requestToken();内的handler.sendRequest(request);函数中给我一个错误

下面是堆栈跟踪：

java.lang.NullPointerException at com.xyz.abc.sendRequest(ServicesHandler.java:443) at com.xyz.abc.ServicesHandlerTest.testSuccess(ServicesHandlerTest.java:150) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498)

解决方法

您应该使用ServicesHandler将模拟注入@InjectMocks中，有关更多信息，请参见文档MockitoAnnotations.initMocks

public class ServicesHandlerTest {

    @InjectMocks
    private ServicesHandler;

    @Mock
    private RestTemplate restTemplate;

    @Mock
    private ObjectMapper mapper;

    @Mock
    private AuthHandler AuthHandler;

    @Before
    public void init() {
        MockitoAnnotations.initMocks(this);
    }

    @After
    public void tearDown() throws Exception {
    }

    @Test
    public void testSuccess() throws Exception {
         Data data = new Data();
         data.setRequestId(UUID.randomUUID().toString());  
         data.setRequestedQuantity(10);

         Request request = new Request();
         request.setData(data );

         System.out.println("request = " + request);
    
    
   Mockito.when(AuthHandler.requestToken()).thenReturn("randomString");
    Mockito.when(restTemplate.postForEntity(anyString(),any(),eq(String.class))).thenReturn(new ResponseEntity<String>(HttpStatus.OK));
    handler.sendRequest(request);
   }
}