Passing an Array to an ArrayAdapter from shared preferences. Android

Question

Afternoon all,

I'm pretty new to android and java in general so I'm not sure if what I'm trying to achieve is possible this way.

I'm trying to implement a Get and Set method in a shared preference class to save an Array and get it out again when required. In a perfect world I would use the code below:

public class dataStorage {
private SharedPreferences sharedPreferences;
private static String PREF_NAME = "prefs";

public dataStorage() {
    // Blank
}

private static String[] getPuzzleList(Context context, String key)
{
    return getPrefs(context).getArray(PREF_NAME, Context.MODE_PRIVATE);

}

private static void setPuzzleList(Context context, String key, String[] stringArray)
{
    SharedPreferences.Editor editor = getPrefs(context).edit();
    editor.putArray(key, stringArray);
    editor.commit();
}

private static SharedPreferences getPrefs(Context context) {
    return context.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE);
}

public static String getPuzzle(Context context, String key) {
    return getPrefs(context).getString(key, "default_string");
}

public static void setPuzzle(Context context, String key, String value) {
    SharedPreferences.Editor editor = getPrefs(context).edit();
    editor.putString(key , value);
    editor.commit();
}
}

My get and set for the individual puzzles work fine because putString and getString are valid methods, whereas getArray and `putArray are not.

Is there a method call I can use to pass string arrays in and out of shared preferences or will I have to implement forloops in order to save them as individual strings? And when I want to pass to an ArrayAdapter, use another for loop to get all the strings into one array again?

Any feedback welcome. Thanks.

Convert your array to a Set and use the get/setStringSet() methods. See: http://stackoverflow.com/questions/7057845/save-arraylist-to-sharedpreferences. — Gary Bak, Apr 22 '16 at 19:14

score 1 · Answer 1 · answered Apr 22 '16 at 19:29

you can put a Set:

private static void setPuzzleList(Context context, String key, String[] stringArray) {
    SharedPreferences.Editor editor = getPrefs(context).edit();
    Set<String> set = new HashSet<String>();
    set.addAll(Arrays.asList(stringArray));
    editor.putStringSet("key", set);
    editor.commit();
}

score 0 · Answer 2 · answered Apr 22 '16 at 19:20

Storing an array

public static void storeArray()
{
    SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
    SharedPreferences.Editor editor = sp.edit();


    for(int i=0;i<stringArray.length;i++)  
    {
       editor.putString("key" + i, stringArray[i]);  
    }

 editor.commit();     
}

Passing an Array to an ArrayAdapter from shared preferences. Android

2 Answers2