How to mock BitmapFactory: Method decodeFile

Question

I have a program which creates thumbnail image from a full size image saved in the storage area . I am trying to test that functionality using mockito but it gives me the following error:

java.lang.RuntimeException: Method decodeFile in android.graphics.BitmapFactory not mocked

//Solved(Updated code)

I am running unit tests using mockito for the first time, Could someone please suggest what I am doing wrong(which I know definitely doing). I am also using ExifInterface to extract the metaData associated with the image but it is giving me the same error again: java.lang.RuntimeException: Method getAttribute in android.media.ExifInterface not mocked.

Here is the MainActivity class :(where I am running the method).

 public class MainActivity extends AppCompatActivity {

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            initValue();
        }

        public void initValue()
        {
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inJustDecodeBounds = true;
            Bitmap thumbnail = createThumbnailFromBitmap("/storage/emulator/0/demo/abcd", 100, 100);

 try {
            ExifInterface exifInterface = new ExifInterface("/storage/emulator/0/demo/abcd");
            String jsonData = exifInterface.getAttribute("UserComment");

            try {
                JSONObject rootJson = new JSONObject(jsonData);
                dateList.add(rootJson.getString("captured"));

            }

            catch(JSONException e)
            {
            }
        }
        catch(Exception e)
        {
            System.out.println("exception "+e);
        }
        }

        private Bitmap createThumbnailFromBitmap(String filePath, int width, int height){
            return ThumbnailUtils.extractThumbnail(BitmapFactory.decodeFile(filePath), width, height);
        }

    }

My test class:

 @RunWith(PowerMockRunner.class)
@PrepareForTest({BitmapFactory.class ,ThumbnailUtils.class})
    public class initValueTest {


        @Mock
        private Bitmap bitmap;


        @Test
    public void initValueTest()
    {
        PowerMockito.mockStatic(BitmapFactory.class);
        PowerMockito.mockStatic(ThumbnailUtils.class);
        when(BitmapFactory.decodeFile(anyString())).thenReturn(bitmap);
        MainActivity mainActivity =  new MainActivity();
        mainActivity.initValue();
    }
    }

Thanks for your help guys. Please excuse if I am doing anything wrong.

score 3 · Accepted Answer · answered Oct 24 '18 at 14:18

3

You can either:

Use power mock to mock static method decodeFile. See docks about it here
Extract bitmap decoding logic to a separate class, extract interface and provide different implementation at run time.

answered Oct 24 '18 at 14:18

Nikolay Ivanov

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1

Hey, Thanks a lot for your quick solution. I wish I could give more than marked as accepted answer and useful. Thanks a lot. I used PowerMockito.mockStatic(BitmapFactory.class); to mock the static method and it worked. – Paramita Oct 24 '18 at 14:33
So, that part was success, I have some more codes in that file which actually reads the metadata from the image using ExifInterface. I did the same mockStatic for the ExifInterface but it is giving me the same error again: Method getAttribute in android.media.ExifInterface not mocked – Paramita Oct 24 '18 at 14:38
As I see in code. getAttribute method is not static so it won't work that way. You need to provide full mock for exifinterface instance and mock it methods. – Nikolay Ivanov Oct 24 '18 at 15:03
Can you write a sample code based on that, I do not know how to full mock that class. Thanks for your help again. – Paramita Oct 24 '18 at 15:08
Thanks for your reply , it helped me a lot. – Paramita Nov 28 '18 at 21:44
How can we extract bitmap decoding logic to a separate class? this method is static... – Vladislaw Vivaldy Sep 23 '20 at 10:05

How to mock BitmapFactory: Method decodeFile

1 Answers1