store/retrieve array list of objects from/to shared preferences example

PrefsUtils.java

import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;

class PrefsUtils {

    private static final String DATA_BASE_RECORDS = "db records", DEFAULT = "";

    static List<Person> allRecords(Context context) {
        List<Person> temp;
        SharedPreferences db = PreferenceManager.getDefaultSharedPreferences(context);
        Gson gson = new Gson();
        String content = db.getString(DATA_BASE_RECORDS, DEFAULT);

        if (content.isEmpty()) {
            temp = new ArrayList<>();
        } else {
            Type type = new TypeToken<List<Person>>() {
            }.getType();
            temp = gson.fromJson(content, type);
        }
        return temp;
    }

    static void addRecord(Context context, String... s){
        List<Person> temp = allRecords(context);
        SharedPreferences db = PreferenceManager.getDefaultSharedPreferences(context);
        SharedPreferences.Editor editor = db.edit();
        temp.add(new Person(s[0], s[1], s[2]));
        Gson gson = new Gson();
        String dbs = gson.toJson(temp);
        editor.putString(DATA_BASE_RECORDS, dbs).apply();
    }
}