public static boolean isImageInputStream imageFile try Image img = ImageIOreadimageFile; if img == null imggetWidthnull = 0 imggetHeightnull = 0 return

@Test public void testIsImage() { InputStream image1 = getClass().getResourceAsStream("test-image.jpg"); assertTrue(isImage(image1));

InputStream image2 = getClass().getResourceAsStream("test-image.png");
assertTrue(isImage(image2));

InputStream nonImage = getClass().getResourceAsStream("test-file.txt");
assertFalse(isImage(nonImage));

InputStream nonExistingFile = getClass().getResourceAsStream("non-existing-file.jpg");
assertFalse(isImage(nonExistingFile));