I have created a small XML parsing application for Android that displays information in a listview and then allows a user to click on the list view and a dialog with further info will pop up.

The problem is that when the screen orientation is changed when a dialog screen is open I get a null pointer error.

The null pointer occurs on the following line:

if(setting.getAddForPublicUserNames() == 1){

This line is part of my dialogPrepare method:

@Override
public void onPrepareDialog(int id, Dialog dialog) {
  switch(id) {
    case (SETTINGS_DIALOG) :                  

        afpunText = "";

        if(setting.getAddForPublicUserNames() == 1){
            afpunText = "Yes";
        }
        else{ 
            afpunText = "No";
        }
      String Text = "Login Settings: " + "\n" 
                       + "Password: " + setting.getPassword()  + "\n" 
                       + "Server: " + setting.getServerAddress() + "\n"
                       + "Register: " + setting.getRegistrarAddress() + "\n"
                       + "Realm: " + setting.getRealm() + "\n"
                       + "Public UserNames: " + afpunText  + "\n"
                       + "Preference Settings: " + "\n"
                       + "Request VDN: " + setting.getRequestVDN() + "\n"
                       + "Handover Settings: " + "\n"
                       + "Enable Handover: " + setting.getEnableHandover() + "\n"
                       + "Hand Over Number: " + setting.getHandoverNum() + "\n";

      AlertDialog settingsDialog = (AlertDialog)dialog; 
      settingsDialog.setTitle("Auth ID: " + setting.getUserName());

      tv = (TextView)settingsDialog.findViewById(R.id.detailsTextView);
      if (tv != null)
        tv.setText(Text);

      break;
  }
}

So the error is that my variable setting is null after the screen orientation changes.

I have tried to use the onSaveInstance state methods to fix that as follows:

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {    


  for(int i = 0; i < settings.size(); i++){
  savedInstanceState.putString("Username"+i, settings.get(i).getUserName());
  savedInstanceState.putString("Password"+i, settings.get(i).getPassword());
  savedInstanceState.putString("Server"+i, settings.get(i).getServerAddress());
  savedInstanceState.putString("Registrar"+i, settings.get(i).getRegistrarAddress());
  savedInstanceState.putString("Realm"+i, settings.get(i).getRealm());
  savedInstanceState.putInt("PUserNames"+i, settings.get(i).getAddForPublicUserNames());
  savedInstanceState.putString("RequestVDN"+i, settings.get(i).getRequestVDN());
  savedInstanceState.putString("EnableHandOver"+i, settings.get(i).getEnableHandover());
  savedInstanceState.putString("HandOverNum"+i, settings.get(i).getHandoverNum()); 
  }

  super.onSaveInstanceState(savedInstanceState);
}

and

@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
  super.onRestoreInstanceState(savedInstanceState);
  //Check to see if this is required

  // Restore UI state from the savedInstanceState.
  // This bundle has also been passed to onCreate.
  for(int i = 0; i<settings.size(); i++){
  settings.get(i).setUserName(savedInstanceState.getString("Username"+i));
  settings.get(i).setPassword(savedInstanceState.getString("Password"+i)) ;
  settings.get(i).setServerAddress(savedInstanceState.getString("Server"+i));
  settings.get(i).setRegistrarAddress(savedInstanceState.getString("Registrar"+i));
  settings.get(i).setRealm(savedInstanceState.getString("Realm"+i));
  settings.get(i).setAddForPublicUserNames(savedInstanceState.getInt("PUserNames"+i));
  settings.get(i).setRequestVDN(savedInstanceState.getString("RequestVDN"+i));
  settings.get(i).setEnableHandover(savedInstanceState.getString("EnableHandOver"+i));
  settings.get(i).setHandoverNum(savedInstanceState.getString("HandOverNum"+i));
  }

}

However the error still remains, I think I have to save the selected setting from what was selected from the ListView? But how do I save a setting object in onSavedInstance?