Question

I am writing an app to save password with a login interface. The user can change the login password. First time, I use the following code to save the password, so that the password will not reset when the app relaunch:

@Override
public void onSaveInstanceState(Bundle savedInstanceState){
    savedInstanceState.putString("pwd", currentPwd);
    super.onSaveInstanceState(savedInstanceState);
}

@Override
public void onRestoreInstanceState(Bundle savedInstanceState){
    currentPwd = savedInstanceState.getString("pwd");
}

But after I asked that, someone in this website suggested me to use “SharedPreferences”. So, I changed the code as follow:

@Override public void onCreate(Bundle savedInstanceState) {     
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.main);
    SharedPreferences settings = getSharedPreferences("setting", 0);
    currentPwd = settings.getString("pwd", "abc");
}

@Override public void onStop(){
    super.onStop();
    SharedPreferences settings = getSharedPreferences("setting", 0);
    SharedPreferences.Editor editor = settings.edit();
    editor.putString("pwd", currentPwd);
    editor.commit();
} 

After my experiment, I found that the password will be reset after one hour which the same as the first code. Have I changed it wrong for the second code? Or there are any suggested way to solve it? Thank you.

Answer 1

Not sure I’m following your code, but here is how I would do this:

To get password:

SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
sp.getString("pwd", "abc");

To set password:

SharedPreferences.Editor editor = sp.edit();
editor.putString("pwd", currentPwd);
editor.commit();

Hope that helps