如何使用PowerMock模拟ServletFileUpload的创建？

Question

我要测试是否在某个类中创建了ServletFileUpload类的实例。

这是正在测试的类：

public class ClassBeingTested {
    public void run()
    {
        new ServletFileUpload();
    }
}

这是测试：

@RunWith(PowerMockRunner.class)
@PrepareForTest(ServletFileUpload.class)
public class MyTest {
    @Test
    public void testServletUploadCreation() throws Exception {
        // Setup mock
        final ServletFileUpload fileUpload = createMockAndExpectNew(
                ServletFileUpload.class);
        replay(fileUpload, ServletFileUpload.class);

        // Invoke method under test
        final ClassBeingTested objectUnderTest = new ClassBeingTested();
        objectUnderTest.run();

        // Verify that ServletFileUpload instance was created
        verify(fileUpload, ServletFileUpload.class);
    }

}

verify语句引发以下异常：

java.lang.AssertionError: 
  Expectation failure on verify:
    org.apache.commons.fileupload.servlet.ServletFileUpload(): expected: 1, 
      actual: 0
    at org.powermock.api.easymock.internal.invocationcontrol.NewInvocationControlAssertionError.throwAssertionErrorForNewSubstitutionFailure(NewInvocationControlAssertionError.java:21)
    at org.powermock.api.easymock.PowerMock.verifyClass(PowerMock.java:2279)
    at org.powermock.api.easymock.PowerMock.verify(PowerMock.java:1646)
    at MyTest.testServletUploadCreation(MyTest.java:21)

为什么？ 我该如何解决？

请注意， 这种模拟构造函数的方式可以在我的代码的其他地方使用。

Answer 1

似乎您需要将此行@PrepareForTest(ServletFileUpload.class)更改为@PrepareForTest(ClassBeingTested.class)