これを試してみてください:
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
Uri selectedImageUri = data.getData();
String picturePath = getPath(getActivity().getApplicationContext(), selectedImageUri);
File file = new File(picturePath);
Date fileDate = new Date(file.lastModifiedDate());
int timestamp = Math.round(fileDate.getTime()/1000);
}
}
public static String getPath(Context context, Uri uri) {
String result = null;
String[] proj = { MediaStore.Images.Media.DATA };
Cursor cursor = context.getContentResolver().query(uri, proj, null, null, null);
if(cursor != null){
if (cursor.moveToFirst()) {
int column_index = cursor.getColumnIndexOrThrow(proj[0]);
result = cursor.getString(column_index);
}
cursor.close();
}
if(result == null) {
result = "Not found";
}
return result;
}