模拟嵌套函数给NPE [英] mocking nested function is giving NPE

问题描述

我在尝试编写单元测试用例
时遇到空指针异常这是类的详细信息：

Hi I am getting Null Pointer Exception while trying to write unit test cases Here is the class detail:

public CreateDraftCampaignResponse createDraftCampaign(CreateDraftCampaignRequest request) throws InvalidInputsException,
        DependencyException, UnauthorizedException {
    CreateDraftCampaignResponse draftCampaignResponse = null;

    try {
        DraftCampaignDetails createdDraft = draftCampaignI.createDraftCampaign(ConvertionUtil
                .getDraftCampaignDetailsfromCreateDraftRequest(request));
        draftCampaignResponse = new CreateDraftCampaignResponse();
        draftCampaignResponse.setDraftCampaignId(createdDraft.getDraftId());       
    }
    catch (Exception e) {
        log.error("Create Draft Campaign Exception", e);
        throw e;
    }
    return draftCampaignResponse;
}

这是ConvertionUtil类：

This is the ConvertionUtil class:

 public static DraftCampaignDetails getDraftCampaignDetailsfromCreateDraftRequest(CreateDraftCampaignRequest request) {

    DraftCampaignDetails draftCampaign = new DraftCampaignDetails();

    DraftCampaignDetailsBase draftCampaignDetailsBase = request
            .getDraftCampaignDetailsBase(); (This is giving exception)
    draftCampaign.setCampaignBudget(draftCampaignDetailsBase
            .getCampaignBudget());
    draftCampaign.setCampaignName(draftCampaignDetailsBase
            .getCampaignName());
    draftCampaign.setDraftCampaignState(draftCampaignDetailsBase
            .getDraftCampaignState());

    draftCampaign.setCreatedUser(request.getUser());

    draftCampaign.setObfuscatedEntityId(request.getObfuscatedEntityId());
    draftCampaign.setCampaignInfo(request.getCampaignInfo());

    return draftCampaign;
}

这就是我尝试过的：

 @Test
 public void createDraft_newDraft() {
     DraftCampaignActivity draftContoller = new DraftCampaignActivity();

     CreateDraftCampaignRequest request = createRequest();
     DraftCampaignDetails details = buildDraftDetails();
     if(draftCampaignI == null){
         System.out.println("sccdscscd");
     }
     //ConvertionUtil action1 = PowerMockito.mock(ConvertionUtil.class);
     //PowerMockito.when(action1.getDraftCampaignDetailsfromCreateDraftRequest(request)).thenReturn(details);
     when(util.getDraftCampaignDetailsfromCreateDraftRequest(request)).thenReturn(details);
     when(draftCampaignI.createDraftCampaign(details)).thenReturn(details);




     CreateDraftCampaignResponse response = new CreateDraftCampaignResponse();
     draftContoller.createDraftCampaign(request);
     response.setDraftCampaignId(details.getDraftId());  
     Assert.assertEquals(response.getDraftCampaignId(),"ww");



 }

我正在获得NPE 。我是Mockito和其他框架的新手。

I am getting NPE. I am a novice in Mockito and other framework. Please help!

推荐答案

它不起作用，因为您尝试模拟静态方法，您做得不好，以至于它调用导致您遇到这种情况的NPE的真实方法。

It doesn't work because you try to mock a static method and you don't do it properly such that it calls the real method which leads to this NPE in your case.

要使用 Powermock 模拟静态方法，您需要：

To mock a static method using Powermock, you need to:

1. 使用 @RunWith（PowerMockRunner.class）批注测试用例的类级别。


2. 在测试的类级别使用 @PrepareForTest（ClassThatContainsStaticMethod.class）批注


3. 使用 PowerMock.mockStatic（ClassThatContainsStaticMethod.class）模拟该类的所有方法。

1. Use the @RunWith(PowerMockRunner.class) annotation at the class-level of the test case.
2. Use the @PrepareForTest(ClassThatContainsStaticMethod.class) annotation at the class-level of the test case.
3. Use PowerMock.mockStatic(ClassThatContainsStaticMethod.class) to mock all methods of this class.

因此，您的情况应该是：

So in your case, you should have something like:

@RunWith(PowerMockRunner.class)
public class MyTestClass {
    @Test
    @PrepareForTest(ConvertionUtil.class)
    public void createDraft_newDraft() {
        ...
        PowerMockito.mockStatic(ConvertionUtil.class);
        PowerMockito.when(
            ConvertionUtil.getDraftCampaignDetailsfromCreateDraftRequest(request)
        ).thenReturn(details);
        ...
    }

有关如何使用Powermock模拟静态方法。

这篇关于模拟嵌套函数给NPE的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！