单元测试 - 获取java.lang.NullPointerException，当尝试使用mockito和powermo

Question

我试图用mockito/powermock模拟私有方法。我得到空指针异常
我尝试做的简单示例是：

实际类

import com.siriusforce.plugin.common.PluginSystem;
import com.wellsfargo.core.business.service.dp.fulfillment.MockitoBusinessService;
public class MockitoBusinessOperationImpl implements MockitoBusinessOperation{
    private MockitoBusinessService mockitoBusinessService = PluginSystem.INSTANCE.getPluginInjector().getInstance(MockitoBusinessService.class);   
    private Long Id;   
    public String creditAproved( Long Id){
       System.out.println("Came Inside MockitoBusinessOperationImpl");
       this.Id = Id; 
       if (this.Id != null){
           System.out.println("Inside creditaproved If statement");
           String Report =  mockitoBusinessService.creditReport(this.Id);
           System.out.println("Mock Object Injected from test class "+ Report);
           return Report;
       } else
           return "Went to Else Part";
    }
    private String inTestMethod(Long Id){
        return "this is working";
    }
}

测试类：

import static org.mockito.Mockito.spy;
import static org.mockito.Mockito.when;
import static org.powermock.api.mockito.PowerMockito.doReturn;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;
import com.siriusforce.plugin.common.PluginSystem;
public class MockitoBusinessServiceTest {
    @Mock
    MockitoBusinessService MockitoBusinessService ;
    @InjectMocks    
    private MockitoBusinessOperation MockitoBusinessOperation = PluginSystem.INSTANCE.getPluginInjector().getInstance(MockitoBusinessOperation.class);
    private Long Id;
    @BeforeMethod
    public void init() {
        MockitoAnnotations.initMocks(this);
        this.Id = 123L;
    }
    @PrepareForTest(MockitoBusinessOperation.class)
    @Test(enabled = true)
    public void testReCalculatePrepaids() throws Exception {
        MockitoBusinessOperation = spy(MockitoBusinessOperation);
        doReturn("this will work hopefully").when(MockitoBusinessOperation, "inTestMethod", this.Id);
        when(MockitoBusinessService.creditReport(this.Id)).thenReturn(new String("Decline by only Me")); 
        String mainReport = MockitoBusinessOperation.creditAproved(this.Id);  
        System.out.println("Indirect Call from actual class MainReport   " + mainReport);
    }
}

当我尝试运行它时，我得到一个NullPointerException：任何解决此问题的建议或任何其他嘲笑私有方法的方法。我不想使用给出的建议来保护该方法，这意味着更改实际方法。我不想对实际进行任何更改

class method
    <failure type="java.lang.NullPointerException">java.lang.NullPointerException
at org.powermock.api.mockito.internal.expectation.PowerMockitoStubberImpl.addAnswersForStubbing(PowerMockitoStubberImpl.java:68)
at org.powermock.api.mockito.internal.expectation.PowerMockitoStubberImpl.prepareForStubbing(PowerMockitoStubberImpl.java:123)
at org.powermock.api.mockito.internal.expectation.PowerMockitoStubberImpl.when(PowerMockitoStubberImpl.java:91)
at com.wellsfargo.core.business.service.dp.fulfillment.MockitoBusinessServiceTest.testReCalculatePrepaids(MockitoBusinessServiceTest.java:54)

Answer 1

你必须使用 PowerMockito.spy() 而不是 Mockito.spy() ！

尝试导入static org.powermock.api.mockito.PowerMockito.spy;