Android - Storing/retrieving strings with shared preferences

Question

As the title says, I want to save and retrieve certain strings. But my code won't pass through the first line neither in retrieve or store. I tried to follow this link: http://developer.android.com/guide/topics/data/data-storage.html

private void savepath(String pathtilsave, int i) {
    String tal = null;
    // doesn't go past the line below
    SharedPreferences.Editor editor = getPreferences(MODE_PRIVATE).edit();
    tal = String.valueOf(i);
    editor.putString(tal, pathtilsave);
    editor.commit();
}

and my retrieve method:

public void getpaths() {
    String tal = null;
    // doesn't go past the line below
    SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
    for (int i = 1; i <= lydliste.length - 1; i++) {
        tal = String.valueOf(i);
        String restoredText = settings.getString(tal, null);
        if (restoredText != null) {
            lydliste[i] = restoredText;
        }
    }
}

lydliste is a static string array. PREFS_NAME is

public static final String PREFS_NAME = "MyPrefsFile";

Answer 1

To save to preferences:

PreferenceManager.getDefaultSharedPreferences(context).edit().putString("MYLABEL", "myStringToSave").apply();  

To get a stored preference:

PreferenceManager.getDefaultSharedPreferences(context).getString("MYLABEL", "defaultStringIfNothingFound"); 

Where context is your Context.

---

If you are getting multiple values, it may be more efficient to reuse the same instance.

 SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
 String myStrValue = prefs.getString("MYSTRLABEL", "defaultStringIfNothingFound");
 Boolean myBoolValue = prefs.getBoolean("MYBOOLLABEL", false);
 int myIntValue = prefs.getInt("MYINTLABEL", 1);

And if you are saving multiple values:

Editor prefEditor = PreferenceManager.getDefaultSharedPreferences(context).edit();
prefEditor.putString("MYSTRLABEL", "myStringToSave");
prefEditor.putBoolean("MYBOOLLABEL", true);
prefEditor.putInt("MYINTLABEL", 99);
prefEditor.apply();  

---

Note: Saving with apply() is better than using commit(). The only time you need commit() is if you require the return value, which is very rare.

Answer 2

private static final String PREFS_NAME = "preferenceName";

public static boolean setPreference(Context context, String key, String value) {
    SharedPreferences settings = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = settings.edit();
    editor.putString(key, value);
    return editor.commit();
}

public static String getPreference(Context context, String key) {
    SharedPreferences settings = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
    return settings.getString(key, "defaultValue");
}

Answer 3

I solved it! It didn't work when I called the methods from within the class! I had to call it from another class for some reason, and write "classname.this" as Context parameter. Here's the final working:

SharedPreferences settings = ctx.getSharedPreferences(PREFS_NAME, 0);
    settings = ctx.getSharedPreferences(PREFS_NAME, 0);
    SharedPreferences.Editor editor = settings.edit();
    editor.putString(tal, pathtilsave);
     editor.commit(); 

Answer 4

Simple steps to save a String with SharedPreferences:

public class MainActivity extends AppCompatActivity {


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    SharedPreferences prefs = this.getSharedPreferences("com.example.nec.myapplication", Context.MODE_PRIVATE);

    prefs.edit().putString("userName", "NEC").apply();

    String name = prefs.getString("userName", "");

    Log.i("saved string", name);
}

Answer 5

try it with context:

final SharedPreferences settings = context.getSharedPreferences(
            PREFS_NAME, 0);

return settings.getString(key, null);

Answer 6

If you do not care about the return value of commit() better use apply() as it being asynchronous is faster that commit().

final SharedPreferences prefs =  context.getSharedPreferences("PREFERENCE_NAME",
                Context.MODE_PRIVATE);
SharedPreferences.Editor editor = prefs.edit();
editor.putString("key", "value");
editor.apply();

As per docs

Unlike commit(), which writes its preferences out to persistent storage synchronously, apply() commits its changes to the in-memory SharedPreferences immediately but starts an asynchronous commit to disk and you won't be notified of any failures. If another editor on this SharedPreferences does a regular commit() while a apply() is still outstanding, the commit() will block until all async commits are completed as well as the commit itself.

Answer 7

The SharedPreferences class allows you to save preferences specific to an android Application.

API version 11 introduced methods putStringSet and getStringSet which allows the developer to store a list of string values and retrieve a list of string values, respectively.

An example of storing an array of strings using SharedPreferences can be done like so:

// Get the current list.

SharedPreferences settings = this.getSharedPreferences("YourActivityPreferences", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
Set<String> myStrings = settings.getStringSet("myStrings", new HashSet<String>());

// Add the new value.

myStrings.add("Another string");


// Save the list.
 editor.putStringSet("myStrings", myStrings); editor.commit();