How to mock static method in Java?

java, junit, mockito, powermock, tdd

Solution

I have no experience with PowerMock, but since you didn't get an answer yet I'm just been reading through the documentation to see if I can help you a bit on your way.

I found that you need to prepare PowerMock so that I knows which static methods it needs to prepare to be mocked. Like so:

@RunWith(PowerMockRunner.class)
@PrepareForTest(BlockAbstractFactory.class) // <<=== Like that
public class testFileGenerator {
    // rest of you class
}

Here you can find more information.

Does that help?

Problem

I have a class `FileGenerator`, and I'm writing a test for the `generateFile()` method that should do the following: 1) it should call the static method `getBlockImpl(FileTypeEnum)` on `BlockAbstractFactory` 2) it should populate variable `blockList` from the subclass method `getBlocks()` 3) it should call a static method `createFile` from a final helper class `FileHelper` passing a String parameter 4) it should call the run method of each `BlockController` in the blockList So far, I have this empty method: ``` public class FileGenerator { // private fields with Getters and Setters public void generateBlocks() { } } ``` I am using JUnit, Mockito to mock objects and I've tried using PowerMockito to mock static and final classes (which Mockito doesn't do). My problem is: my first test (calling method `getBlockList()` from `BlockAbstractFactory`) is passing, even though there is no implementation in `generateBlocks()`. I have implemented the static method in `BlockAbstractFactory` (returning null, so far), to avoid Eclipse syntax errors. How can I test if the static method is called within `fileGerator.generateBlocks()`? Here's my Test Class, so far: ``` @RunWith(PowerMockRunner.class) public class testFileGenerator { FileGenerator fileGenerator = new FileGenerator(); @Test public void shouldCallGetBlockList() { fileGenerator.setFileType(FileTypeEnum.SPED_FISCAL); fileGenerator.generateBlocks(); PowerMockito.mockStatic(BlockAbstractFactory.class); PowerMockito.verifyStatic(); BlockAbstractFactory.getBlockImpl(fileGenerator.getFileType()); } } ```

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