android - How to get Exif data from an InputStream rather than a File?

Question

The reason why I am asking this is because the callback of the file chooser Intent returns an Uri.

Open file chooser via Intent:

Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Select Picture"), CHOOSE_IMAGE_REQUEST);

Callback:

@Override
public void onActivityResult(int requestCode, int resultCode, final Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == CHOOSE_IMAGE_REQUEST && resultCode == Activity.RESULT_OK) {

        if (data == null) {
            // Error
            return;
        }

        Uri fileUri = data.getData();
        InputStream in = getContentResolver().openInputStream(fileUri);

        // How to determine image orientation through Exif data here?
    }
}

One way would be to write the InputStream to an actual File, but this seems like a bad workaround for me.

Answer 1

After the 25.1.0 support library was introduced, now is possible to read exif data from URI contents (content:// or file://) through an InputStream.

Example: First add this line to your gradle file:

compile 'com.android.support:exifinterface:25.1.0'

Uri uri; // the URI you've received from the other app
InputStream in;
try {
  in = getContentResolver().openInputStream(uri);
  ExifInterface exifInterface = new ExifInterface(in);
  // Now you can extract any Exif tag you want
  // Assuming the image is a JPEG or supported raw format
} catch (IOException e) {
  // Handle any errors
} finally {
  if (in != null) {
    try {
      in.close();
    } catch (IOException ignored) {}
  }
}

For more information check: Introducing the ExifInterface Support Library, ExifInterface.