How to use SharedPreferences to save and read from a Class

Question

I want to use the SharedPreferences in a Class that has no Activity. I have wrote this code but im still getting an error. Can you help me out please?

package com.example.keypass;

import android.content.Context;
import android.content.SharedPreferences;


public class test {
    SharedPreferences sharedPreferences;


    public void loadInt(){
        sharedPreferences = this.getSharedPreferences("com.example.keypass",Context.MODE_PRIVATE);
        int usrPassword = sharedPreferences.getInt("meinInteger", 0);
    }

}

If I use the same code in a Class with Activity it works. But in this class is not working.

Answer 1

Here Maybe this help

Its a good practice making separate class file for shared prefrence

first, create a file(class) name Constants.java

   public class Constants {
    
        static Constants _instance;
    
        Context context;
        SharedPreferences sharedPref;
        SharedPreferences.Editor sharedPrefEditor;
    
        public static Constants instance(Context context) {
            if (_instance == null) {
                _instance = new Constants();
                _instance.configSessionUtils(context);
            }
            return _instance;
        }

    public static Constants instance() {
        return _instance;
    }

    public void configSessionUtils(Context context) {
        this.context = context;
        sharedPref = context.getSharedPreferences("AppPreferences", Activity.MODE_PRIVATE);
        sharedPrefEditor = sharedPref.edit();
    }

    public void storeValueString(String key, String value) {
        sharedPrefEditor.putString(key, value);
        sharedPrefEditor.commit();
    }

    public String fetchValueString(String key) {
        return sharedPref.getString(key, null);
    }
}

The above code will generate an XML file inside your phone with the name AppPreferences

where you can store value in key-value pair

Now go to an activity where you want to access shared preference

Constants.instance(this.getApplicationContext());

Now when you want to store inside shared preference use like that

Constants.instance().storeValueString("companyKey", "Brainwash Inc.");

now when you want to fetch data from shared prefrence

String companyName = (Constants.instance().fetchValueString("companyKey"));

Note Its for Activity if you want to use inside fragments use getactivity() instead of getapplicationcontext()