Saving Bitmap to External Storage in Android API 28 Result in 0 B file

Question

I'm trying to save a bitmap to external storage. I have used the code that I have found in android - save image into gallery. However, the resulting file is 0 B in size but do contain thumbnail. My code is:

private fun saveBitmap(bitmap: Bitmap, name: String) {
    val contentValues = contentValuesOf(
        MediaStore.MediaColumns.TITLE to name,
        MediaStore.MediaColumns.DISPLAY_NAME to name,
        MediaStore.MediaColumns.MIME_TYPE to "images/jpeg",
        MediaStore.MediaColumns.DATE_ADDED to System.currentTimeMillis()
    )

    val resolver = contentResolver
    val uri = resolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, contentValues)
    val outputStream = resolver.openOutputStream(uri!!)!!
    bitmap.compress(Bitmap.CompressFormat.JPEG, 80, outputStream)
    outputStream.flush()
    outputStream.close()
}

`the resulting file is 0 B in size but do contain thumbnail. `? That is impossible. If a file is 0 bytes then it contains nothing and certainly not a thumbnail. How did you determine that all? — blackapps, Jan 17 '20 at 09:17
are you added read and write permission in manifest file? above Marshmallow version need user permission. — GParekar, Jan 17 '20 at 09:22
@GParekar Yes, I've added permission to write to external storage — H. Artajaya, Jan 17 '20 at 09:26

score 1 · Accepted Answer · answered Jan 17 '20 at 11:24

Rather than saving to JPEG try saving as PNG

try (FileOutputStream out = new FileOutputStream(filename)) {
    bmp.compress(Bitmap.CompressFormat.PNG, 100, out); // bmp is your Bitmap instance
    // PNG is a lossless format, the compression factor (100) is ignored
} catch (IOException e) {
    e.printStackTrace();
}

Please find similar question answered here

Also as mention in comment please check, have you taken permission for read/write access? If not then please refer the below code.

if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
Log.v(TAG,"Permission is granted");
//File write logic here
return true;

}

Thanks, by changing the format to png it fixed the problem. But why is changing the format to png fixed the problem? Is jpeg not supported by android? — H. Artajaya, Jan 21 '20 at 06:54

Saving Bitmap to External Storage in Android API 28 Result in 0 B file

1 Answers1