如何将更新的图像输出到图库？

Question

The exif interface is used in my application to write new data to a stored image,captured using the camera intent in Android.

The problem is when the image file is output to storage, my code for updating the attributes of the image doesn't actually update the stored image when I view details of the image in the gallery.

For example I use the UserComment tag to add some generic text as a test input but this is not displayed in the image's details on the device.

My question is, how can I check if the data is actually being written to the file?

If I know that the attributes are being appended to the image then I can debug the storage of the file as the problem.

This is the getOutputPhotoFile() method which retrieves the last captured image in the directory of the project:

private File getOutputPhotoFile() throws IOException {
          File directory = new File(Environment.getExternalStoragePublicDirectory(
                        Environment.DIRECTORY_PICTURES), getPackageName());
          if (!directory.exists()) {
            if (!directory.mkdirs()) {
              Log.e(TAG, "Failed to create storage directory.");
              return null;
            }
          }


          String timeStamp = new SimpleDateFormat("yyyMMdd_HHmmss", Locale.ENGLISH).format(new Date());

          File[] files = directory.listFiles();

          File origFile =  new File(directory.getPath(), "IMG_" + timeStamp + ".jpg");

          if(files.length!=0) {
              File newestFile = files[files.length-1];
              origFile =  new File(directory.getPath() + File.separator + newestFile.getName());
          }

          String mString = "Generic Text..";     
          ExifInterface exifFile = new ExifInterface(origFile.getAbsolutePath());
          exifFile.setAttribute("UserComment", mString);

          exifFile.setAttribute(ExifInterface.TAG_GPS_LATITUDE,
            String.valueOf(latituteField.toString()));

          exifFile.setAttribute(ExifInterface.TAG_GPS_LONGITUDE, 
            String.valueOf(longitudeField.toString()));

          exifFile.saveAttributes();

      return origFile; 

    }

Answer 1

Upon looking into ExifInterface API , it seems that there is no Exif TAG with the name "UserComment".

It seems that it only supports TAGs mentioned in the given API.

After setting the location values, you can use same ExifInterface API getAttribute(ExifInterface.TAG_GPS_LATITUDE,) and getAttribute(ExifInterface.TAG_GPS_LONGITUDE) to check whether the file has the values set.