How to Write/Read in JavaFX with Gluon Plugin - javafx

Question

I am trying to write/read files in JavaFX while using the Gluon plugin, and I am not having any luck. If i run the program as a Desktop App, it works fine, I've even used the same functions in Android IDE and it works fine, however if I send the program to my phone with Gluon, it does not work. I wanting to know how to save/read to files in Gluon, and what have I done wrong, and why does it work as Desktop and on Android but not Gluon. The two fcns I used are:
public void writeToFile() {
try {
FileOutputStream f = new FileOutputStream("Meal1_Protein.txt");
f.write(choice.getBytes()); //Choice is input from a dropdown
f.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
Toast toast = new Toast(choice);
toast.show();
}
public void readFromFile(){
try {
FileInputStream f = new FileInputStream("Meal1_Protein.txt");
InputStreamReader is = new InputStreamReader(f);
BufferedReader br = new BufferedReader(is);
StringBuffer buff = new StringBuffer();
String lines;
while((lines = br.readLine())!=null){
buff.append(lines);
buff.append("\n");
}
carbInput.setText(buff.toString()); // inserting into a txtfield
//to see if it I can read strings back in.
Toast toast = new Toast(buff.toString());
toast.show();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}