How can I mock private static method with PowerMockito?

Question

I\'m trying to mock private static method anotherMethod(). See code below

public class Util {
    public static String method(){
        return          


        

Answer 1

To to this, you can use PowerMockito.spy(...) and PowerMockito.doReturn(...).

Moreover, you have to specify the PowerMock runner at your test class, and prepare the class for testing, as follows:

@PrepareForTest(Util.class)
@RunWith(PowerMockRunner.class)
public class UtilTest {

   @Test
   public void testMethod() throws Exception {
      PowerMockito.spy(Util.class);
      PowerMockito.doReturn("abc").when(Util.class, "anotherMethod");

      String retrieved = Util.method();

      Assert.assertNotNull(retrieved);
      Assert.assertEquals(retrieved, "abc");
   }
}

Hope it helps you.

Answer 2

If anotherMethod() takes any argument as anotherMethod(parameter), the correct invocation of the method will be:

PowerMockito.doReturn("abc").when(Util.class, "anotherMethod", parameter);

Answer 3

I'm not sure what version of PowerMock you are using, but with the later version, you should be using @RunWith(PowerMockRunner.class) @PrepareForTest(Util.class)

Saying this, I find using PowerMock to be really problematic and a sure sign of a poor design. If you have the time/opportunity to change the design, I would try and do that first.