Toast for retrieving SharedPreferences returns empty value

Question

I am trying to store the SIM Serial number as a value into the SharedPreferences but when i do a Toast to test for the value it is empty.

    TelephonyManager tMgr=(TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);
    String ss = tMgr.getSimSerialNumber();

    // Writing data to SharedPreferences
    Editor editor = sp.edit();
    editor.putString("serial", ss);
    editor.commit();

    String value = settings.getString("serial", "");
    Toast.makeText(this, value, Toast.LENGTH_LONG).show();  

Answer 1

• Storing the serial:

  SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
  SharedPreferences.Editor editor = prefs.edit();
  editor.putString("serial", ss);
  editor.commit();
  

• Retrieving the serial:

  SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
  String value = prefs.getString("serial", "000000000000");
  

where 000000000000 is the default value that will be returned to you if the sharedPreferences is not stored.

Answer 2

   public void saveSerial(String serial){
      SharedPreferences prefs = getSharedPreferences("SIMSerial",Context.MODE_PRIVATE);
      SharedPreferences.Editor editor = prefs.edit();
      editor.putString("Serial", serial);
      editor.commit();
     }
    public String getSerial(){
      String getSIMSerial;
      SharedPreferences prefs = getSharedPreferences("SIMSerial",Context.MODE_PRIVATE);
      getSIMSerial = prefs.getString("Serial", "Default value");
        return getSIMSerial;
     }

The serial number will be stored in a xml that you can found at /data/data/YOUR_APP/shared_prefs/

Answer 3

Short answer: Check on how you're instantiating your settings variable. You were using sp.edit(), so it should probably be sp.getString too.