Mocking rest client class using mockito throw null pointer exception

Question

Hi i have class RestClientUtil which perform all the connection related operation with server and get the response using rest Services. When i tried to mock my restClientUtil its mocked successfully but when i tried calling method of this class,method will return response as null.when i see restClientUtil variable in debug mode ,property of this class like pbsOrderStatusUrl sellerCode etc are coming null may be because of this reason response is coming null so please tell me the way to write mockito of my OrderStatusUpdate which is based upon response of RestClientUtil class

This is the method of RestClientUtilClass

 public class RestClientUtil{
       @Value("#{externalProperties['PBSUrl']}")
      private String pbsUrl;

    @Value("#{externalProperties['PBSOrderStatusUrl']}")
    private String pbsOrderStatusUrl;

    @Value("#{externalProperties['sellerCode']}")
    private String sellerCode;

    @Value("#{externalProperties['PAYMENT_CLIENT_URL']}")
    private String paymentClientURL;

    @Value("#{externalProperties['PBS_COMMUNICATION_URL']}")
    private String pbsCommunicationURL;

    private WebResource webResource;    

public com.mycompany.wrapper.orderstatusupdate.resp.Response orderStatusUpdateToProvider(
            com.mycompany.wrapper.orderstatusupdate.req.Request req, String specificURL)
            throws EcomGenericException {
        com.mycompany.wrapper.orderstatusupdate.resp.Response response = null;
        int i = 0;
        for (; i < 3; i++) {
//pbsUrl is some UrlTo differntServer
            try {
                Client client = Client.create();
                WebResource webResource = client.resource(UriBuilder.fromUri(
                        pbsUrl).build());
                log.debug("Input to the PBS system for orderStatusUpdateToProvider ==> "
                        + req);
                MultivaluedMap queryParams = new MultivaluedMapImpl();
                queryParams.add("sellerCode", sellerCode);
                response = webResource.path("seller").path("orders")
                        .path(specificURL).queryParams(queryParams)
                        .header("correlationId", req.getCorrelationId())
                        .type(MediaType.APPLICATION_XML)
                        .post(com.mycompany.wrapper.orderstatusupdate.resp.Response.class,
                                req);
                log.trace("response ==> " + response);
                if (null == response) {
                    log.error("Order Update Status  is null");
                    throw new EcomGenericException("validation_500");
                }
                break;
            } catch (UniformInterfaceException e) {

            }
        }

        return response;
    }
}

This is the class where i am calling RestClientUtil Method

     @Service
    public class OrderStatusUpdate {

        private static final Logger logger = Logger
                .getLogger(OrderStatusUpdate.class);
        @Resource(name = "restClientUtil")
        protected RestClientUtil restClientUtil;

        @Resource(name = "blOrderService")
        protected OrderService orderService;
        public void setRestClientUtil(RestClientUtil restClientUtil) {
            this.restClientUtil = restClientUtil;
        }

        public void setOrderService(OrderService orderService) {
            this.orderService = orderService;
        }


        public void orderStatusUpdate(Order order, String providerStatus, String targetStatus,
                String dateTime, String targetURI) throws EcomGenericException,  org.broadleafcommerce.core.pricing.service.exception.PricingException {

            Request request = new ObjectFactory()
                    .createRequest();
            Request.Order orderReq = new Request.Order();
            orderReq.setOrderId(order.getOrderNumber());
            orderReq.setStatus(providerStatus);
            orderReq.setDateTime(dateTime);
            request.setOrder(orderReq);
            request.setCorrelationId(UUID.randomUUID().toString());
            com.mycompany.wrapper.orderstatusupdate.resp.Response response = restClientUtil.orderStatusUpdateToProvider(request,targetURI);
            if (response != null && ApplicationConstants.PROVIDER_SUCCESS_IDENTIFIER.equals(response.getStatus().getCode())) {
                order.setStatus(CustomOrderStatus.getInstance(targetStatus));
                orderService.save(order, false);
            } else {
logger.error("OrderStatusUpdate call failed from the Provider end for ECOM OrderID " +order.getId()+ " with ErrorCode "+ response.getStatus().getCode() + " with Error message "+ response.getStatus().getMessage());
            throw new EcomGenericException("validation_500");
            }
        }

    }

This is the mockito Test i tried to implement

  public class OrderStatusUpdateTest {

    protected RestClientUtil restClientUtil;

    protected OrderService orderService;

    protected OrderStatusUpdate orderStatusUpdate;
    protected Request request;
    private Response response;
    private Order blcOrder;
    private com.mycompany.account.CustomOrderStatus CustomOrderStatus;

    @Before
    public void setUp() {
     restClientUtil=mock(RestClientUtil.class);
     orderService=mock(OrderService.class);
     blcOrder=new OrderImpl();
     request=new Request();
     blcOrder.setStatus(CustomOrderStatus.PAYMENT_COMPLETED);
     orderStatusUpdate=new OrderStatusUpdate();
     orderStatusUpdate.setOrderService(orderService);
     orderStatusUpdate.setRestClientUtil(restClientUtil);
     Request.Order order=new Request.Order();
     order.setOrderId("123455");
     order.setStatus("PAYMENT COMPLETED");
     order.setDateTime("2013-11-21T09:30:47+0500");
     request.setCorrelationId("12343");
     request.setOrder(order);

     when(restClientUtil.orderStatusUpdateToProvider(request, "http://localhost:8080/")).thenReturn(response);
    }

    @Test
    public void test() throws PricingException {

        orderStatusUpdate.orderStatusUpdate(blcOrder, "PAYMENT COMPLETED","IN_PAYMENT", "2013-11-21T09:30:47+0500", "http://localhost:8080/");
        verify(restClientUtil.orderStatusUpdateToProvider(request, "http://localhost:8080/"));
        verify(orderService.save(blcOrder, false));

        fail("Not yet implemented");
    }

}

this is the error log

 java.lang.NullPointerException
    at com.mycompany.api.service.orderstatusupdate.OrderStatusUpdate.orderStatusUpdate(OrderStatusUpdate.java:72)
    at com.mycompany.api.service.orderstatusupdate.test.OrderStatusUpdateTest.test(OrderStatusUpdateTest.java:56)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Answer 1

In the line:

when(restClientUtil.orderStatusUpdateToProvider(request,"http://localhost:8080")).thenReturn(response);

response is not initialized.

The if-else condition is incorrect in orderStatusUpdate method, because if the response is null , the logger still tries to access the status code from it.