How to check if SharedPreferences exists or not

Question

I'm checking in this way if the file exists, but I need to go beyond, I need to know if there is one in specific, is there any way?

File f = new File("/data/data/com.eventrid.scanner/shared_prefs/Eventrid.xml");
          if (f.exists()){

          }
          else{

          }  

Answer 1

SharedPreferences has a contains(String key) method, which can be used to check if an entry with the given key exists.

http://developer.android.com/reference/android/content/SharedPreferences.html

Answer 2

Well, one could do:

    SharedPreferences sharedPrefs = getSharedPreferences("sp_name", MODE_PRIVATE);
    SharedPreferences.Editor ed;
    if(!sharedPrefs.contains("initialized")){
        ed = sharedPrefs.edit();

        //Indicate that the default shared prefs have been set
        ed.putBoolean("initialized", true);

        //Set some default shared pref
        ed.putString("myDefString", "wowsaBowsa");

        ed.commit();
    }  

Answer 3

Another solution:

If you know the exact number of preferences you have you can:

public void isPreferencesSet(Context context){
    SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
    return (sharedPreferences.getAll().size() == exactNumberOfPreferences);
}

This works because the preferences file stored in /data/data/myApp/shared_prefs/myApp_prefrences.xml contains a preference's value pair only if its value has been set.

Answer 4

Check if SharedPreferences key exists:

    SharedPreferences mPrefs = PreferenceManager.getDefaultSharedPreferences(this);
    if(mPrefs.getAll().containsKey("KeyName")){

Answer 5

You can try this

 fun checkLoginInfo(): Boolean{
    val saveLogin = sharedPreferences.getBoolean(SAVE_LOGIN, false)
    return saveLogin
}

 Checks whether the preferences contains a preference. 
 @param(SAVE_LOGIN) key The name of the preference to check.
 @param(false) default
 @return Returns true if the preference exists in the preferences, otherwise false.