使用PowerMock模拟在测试类的构造函数中调用的私有方法

Question

我不知道Powermock是否可以实现这一点。我需要使用Powermock来模拟在我需要测试的类的构造函数中调用的私有方法。所以我有一个这样的测试类：

@RunWith(PowerMockRunner.class)
@PrepareForTest(XMLTransaction.class)
public class CloseSummaryOrCloseTrailerResponseTest {
    public final static String URL="WL_APPSERVER";
    private XMLTransaction xmlTransaction; 

    @Before
    public void initMocks() throws Exception {
        xmlTransaction = PowerMockito.spy(new XMLTransaction(URL)); 
        PowerMockito.doAnswer(new org.mockito.stubbing.Answer<Object>() {
            @Override
            public Object answer(InvocationOnMock invocation) throws Throwable {
                return null; //does nothing
            }
        }).when(xmlTransaction.getClass(), "initialize");
        PowerMockito.doNothing().when(xmlTransaction.getClass(), "initialize");             
    }

    @Test
    public void whenCloseSummaryResponseNoErrorExpectCorrectXmlMsgProduced () throws Exception
    {
    //set the mock object here
        try {                    
            String actualXmlScannerMsg = xmlTransaction.closeSummaryResponseToXMLNoErrors(mockCloseTrailerResponse);
            Assert.assertNotNull(actualXmlScannerMsg);
            Assert.assertEquals(msgNoCarReturnCharCloseSummaryResponse, actualXmlScannerMsg);   
        }
        catch(JsonProcessingException jEx)
        {
            Assert.fail("JsonProcessingException: " + jEx.getMessage());
        }
        catch(Exception ex)
        {
            Assert.fail("Exception occurred: " + ex.getMessage());
        }
    }
}

创建间谍时，我得到一个空指针异常。构造函数new XMLTransaction（URL）调用initialize方法，这是我什么都不做的方法。

有没有办法解决这个问题。如果我使用默认构造函数，则不会创建该类。

Answer 1

我想出来了......我创建了一个默认构造函数，并将在initialize方法中实例化的所有类设置为null。从initMock（）中删除了这个

PowerMockito.doAnswer(new org.mockito.stubbing.Answer<Object>() {
            @Override
            public Object answer(InvocationOnMock invocation) throws Throwable {
                return null; //does nothing
            }
        }).when(xmlTransaction.getClass(), "initialize");
        PowerMockito.doNothing().when(xmlTransaction.getClass(), "initialize");