Hi, I saved the diagram using:
try {
FileOutputStream fileOut = openFileOutput(fileName,Context.MODE_PRIVATE);
fileOut.flush();
diagram.saveTo(fileOut);
fileOut.close;
} catch (IOException e) {
    e.printStackTrace();
}

and I load it using:
try {
    FileInputStream inputStream = openFileInput(o);
     diagram.loadFrom(inputStream);
      inputStream.close();
  } catch (IOException e) {
        e.printStackTrace();
}

but I would like to know in which folder of the device it saves the diagram, because I need the file saved, could you tell me or is there another way to save the file in order to get it outside the application? I don't mean the diagram but the file serialized when saved, in which folder does it put it?

I found the path the problem is that I cannot access to it, I can simply read the string with the name of the path but I cannot access to the files and I need a way to get the files saved. In this way I have the name of the folder but I cannot find the folder on my device.