88
To write,
SharedPreferences prefs = PreferenceManager
.getDefaultSharedPreferences(this);
JSONArray jsonArray = new JSONArray();
jsonArray.put(1);
jsonArray.put(2);
Editor editor = prefs.edit();
editor.putString("key", jsonArray.toString());
System.out.println(jsonArray.toString());
editor.commit();
To Read,
try {
JSONArray jsonArray2 = new JSONArray(prefs.getString("key", "[]"));
for (int i = 0; i < jsonArray2.length(); i++) {
Log.d("your JSON Array", jsonArray2.getInt(i)+"");
}
} catch (Exception e) {
e.printStackTrace();
}
Other way to do same:
//Retrieve the values
Gson gson = new Gson();
String jsonText = Prefs.getString("key", null);
String[] text = gson.fromJson(jsonText, String[].class); //EDIT: gso to gson
//Set the values
Gson gson = new Gson();
List<String> textList = new ArrayList<String>(data);
String jsonText = gson.toJson(textList);
prefsEditor.putString("key", jsonText);
prefsEditor.apply();
Using GSON in Java:
public void saveArrayList(ArrayList<String> list, String key){
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(activity);
SharedPreferences.Editor editor = prefs.edit();
Gson gson = new Gson();
String json = gson.toJson(list);
editor.putString(key, json);
editor.apply();
}
public ArrayList<String> getArrayList(String key){
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(activity);
Gson gson = new Gson();
String json = prefs.getString(key, null);
Type type = new TypeToken<ArrayList<String>>() {}.getType();
return gson.fromJson(json, type);
}
Using GSON in Kotlin
fun saveArrayList(list: java.util.ArrayList<String?>?, key: String?) {
val prefs: SharedPrefSo from the android developer site on Data Storage:
User Preferences
Shared preferences are not strictly for saving "user preferences," such as what ringtone a user has chosen. If you're interested in creating user preferences for your application, see PreferenceActivity, which provides an Activity framework for you to create user preferences, which will be automatically persisted (using shared preferences).
So I think it is okay since it is simply just key-value pairs which are persisted.
To the original poster, this is not that hard. You simply just iterate through your array list and add the items. In this example I use a map for simplicity but you can use an array list and change it appropriately:
// my list of names, icon locations
Map<String, String> nameIcons = new HashMap<String, String>();
nameIcons.put("Noel", "/location/to/noel/icon.png");
nameIcons.put("Bob", "another/location/to/bob/icon.png");
nameIcons.put("another name", "last/location/icon.png");
SharedPreferences keyValues = getContext().getSharedPreferences("name_icons_list", Context.MODE_PRIVATE);
SharedPreferences.Editor keyValuesEditor = keyValues.edit();
for (String s : nameIcons.keySet()) {
// use the name as the key, and the icon as the value
keyValuesEditor.putString(s, nameIcons.get(s));
}
keyValuesEditor.commit()
You would do something similar to read the key-value pairs again. Let me know if this works.
Update: If you're using API level 11 or later, there is a method to write out a String Set
I loaded an array of waist sizes (already created in my array.xml) into my preferences.xml file with the code below. @array/pant_inch_size is the id of the entire array.
<ListPreference
android:title="choosepantsize"
android:summary="Choose Pant Size"
android:key="pantSizePref"
android:defaultValue="34"
android:entries="@array/pant_inch_size"
android:entryValues="@array/pant_inch_size" />
This populated the menu with choices from the array. I set the default size as 34, so when the menu pops up, they see size 34 is pre-selected.