How to mock a void static method to throw exception with Powermock?

Question

I am trying to use Powermock and Mockito to mock a void static method to throw exception as below. But I met a problem. Unless I make the two invocations of Adder.add() with the same argument, the mocked IOException won't be thrown.

BTW, I've added @RunWith(PowerMockRunner.class) and @PrepareForTest(Adder.class) to the unit test class.

class Adder{     public static void add(int i) throws IOException{         return;     } }  @Test public void testAdder() throws IOException{     PowerMockito.mockStatic(Adder.class);     PowerMockito.doThrow(new IOException()).when(Adder.class);     Adder.add(12);     try {         Adder.add(11);     } catch (Exception e) {         // TODO Auto-generated catch block         e.printStackTrace();     }     // assert things  } 

Thanks in advance. :)

Answer is as below.

After consulting here http://code.google.com/p/powermock/issues/detail?id=278 , in fact Adder.add(12) above is part of setting up mock static method. It means when invoking Adder.add() with argument 12, IOException will be thrown. It is hard to understand, right? :) So it should be written as below.

PowerMockito.mockStatic(Adder.class); PowerMockito.doThrow(new IOException()).when(Adder.class); Adder.add(anyInt()); 

Answer 1

Answer is as below.

After consulting here http://code.google.com/p/powermock/issues/detail?id=278 , in fact Adder.add(12) above is part of setting up mock static method. It means when invoking Adder.add() with argument 12, IOException will be thrown. It is hard to understand, right? :) So it should be written as below.

PowerMockito.mockStatic(Adder.class); PowerMockito.doThrow(new IOException()).when(Adder.class); Adder.add(anyInt()); 

EDIT:
Link is dead, try Internet Archive one instead.

Answer 2

Or

PowerMockito.mockStatic(Adder.class); PowerMockito.doThrow(new IOException()).when(Adder.class, "add", Mathers.eq(12));