AppPreference.Java

import android.content.Context;
import android.content.SharedPreferences;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.util.Log;

import java.lang.reflect.Field;
import java.util.Set;
import java.util.prefs.AbstractPreferences;

/**
 * Created by vaibha.jani on 1/4/2016.
 */
public class AppPreferences {

    public static final class App {

        public static final String SAMPLE = "sample";
    }

    public static final class User {

        public static final String SAMPLE = "sample";
    }

    public static final String APP_PREFERENCES_FILE_NAME = "app_preferences";

    private static SharedPreferences sharedPreferencesSingleton;

    private static synchronized SharedPreferences getInstance() {

        if (sharedPreferencesSingleton == null) {

            Context context = BaseApplication.getInstance();
            sharedPreferencesSingleton = context.getSharedPreferences(APP_PREFERENCES_FILE_NAME, Context.MODE_PRIVATE);
        }

        return sharedPreferencesSingleton;
    }

    public static void deletePreference(String prefKey) {

        SharedPreferences sharedPreferences = getInstance();

        if (sharedPreferences.contains(prefKey)) {

            sharedPreferences.edit().remove(prefKey).apply();
        }
    }

    public static void deleteAllPreference() {

        SharedPreferences sharedPreferences = getInstance();

        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.clear();
        editor.apply();
        editor.commit();
    }

    public static void deleteUserPreference() {

        deletePreferenceForClass(User.class);
    }

    public static void deleteAppPreference() {

        deletePreferenceForClass(App.class);
    }

    private static void deletePreferenceForClass(Class<?> className) {

        Class<?> userClass = className;

        Field[] fields = userClass.getDeclaredFields();
        for (Field field : fields) {

            try {

                String fieldValue = (String) field.get(null);

                Log.d("DELETING PREF KEY", fieldValue);

                deletePreference(fieldValue);

            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        }
    }

    public static boolean contains(String key) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.contains(key);
    }

    //Booleans
    public static boolean getBoolean(String booleanKey) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.getBoolean(booleanKey, false);
    }

    public static boolean getBoolean(String booleanKey, boolean defaultValue) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.getBoolean(booleanKey, defaultValue);
    }

    public static boolean putBoolean(String booleanKey, boolean value) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.edit().putBoolean(booleanKey, value).commit();
    }

    //Integers
    public static int getInt(String intKey) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.getInt(intKey, 0);
    }

    public static int getInt(String intKey, int defaultValue) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.getInt(intKey, defaultValue);
    }

    public static boolean putInt(String intKey, int value) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.edit().putInt(intKey, value).commit();
    }

    //Strings
    public static String getString(String stringKey) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.getString(stringKey, null);
    }

    public static String getString(String stringKey, @Nullable String defaultValue) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.getString(stringKey, defaultValue);
    }

    public static boolean putString(String stringKey, String value) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.edit().putString(stringKey, value).commit();
    }


    //Floats
    public static Float getFloat(String stringKey) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.getFloat(stringKey, 0);
    }

    public static Float getFloat(String stringKey, float defaultValue) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.getFloat(stringKey, defaultValue);
    }

    public static boolean putFloat(String stringKey, float value) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.edit().putFloat(stringKey, value).commit();
    }

    //Strings Sets
    public static Set<String> getStringSet(String stringSetKey) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.getStringSet(stringSetKey, null);
    }

    public static Set<String> getStringSet(String stringSetKey, @Nullable Set<String> defaultValue) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.getStringSet(stringSetKey, defaultValue);
    }

    public static boolean putStringSet(String stringSetKey, Set<String> value) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.edit().putStringSet(stringSetKey, value).commit();
    }

    //Longs
    public static long getLong(String longKey) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.getLong(longKey, 0);
    }

    public static long getLong(String longKey, long defaultValue) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.getLong(longKey, defaultValue);
    }

    public static boolean putLong(String longKey, long longValue) {

        SharedPreferences sharedPreferences = getInstance();

        return sharedPreferences.edit().putLong(longKey, longValue).commit();
    }

    //Encrypted
    public static boolean putStringEncrypted(String key, String value) {

        SharedPreferences sharedPreferences = getInstance();

        value = EncryptionUtils.encrypt(value, BaseApplication.getInstance());

        return sharedPreferences.edit().putString(key, value).commit();
    }

    public static String getStringEncrypted(String key, String defaultValue) {

        SharedPreferences sharedPreferences = getInstance();

        if (sharedPreferences.contains(key)) {

            String value = sharedPreferences.getString(key, defaultValue);
            return EncryptionUtils.decrypt(value, BaseApplication.getInstance());

        } else {

            return defaultValue;
        }
    }

    public static String getStringEncrypted(String key) {

        return AppPreferences.getStringEncrypted(key, null);
    }

    public static boolean putLongEncrypted(String key, long value) {

        return AppPreferences.putStringEncrypted(key, Long.toString(value));
    }

    public static long getLongEncrypted(String key, long defaultValue) {

        String value = AppPreferences.getStringEncrypted(key, null);

        if(value == null) {

            return defaultValue;

        } else {

            long longValue = defaultValue;

            try {

                longValue = Long.parseLong(value);

            } catch (NumberFormatException e) {
                e.printStackTrace();
            }

            return longValue;
        }
    }
    
    public static long getLongEncrypted(String key) {

        return AppPreferences.getLongEncrypted(key, 0);
    }
    
    public static boolean putIntEncrypted(String key, int value) {

        return AppPreferences.putStringEncrypted(key, Integer.toString(value));
    }

    public static int getIntEncrypted(String key, int defaultValue) {

        String value = AppPreferences.getStringEncrypted(key, null);

        if(value == null) {

            return defaultValue;

        } else {

            int intValue = defaultValue;

            try {

                intValue = Integer.parseInt(value);

            } catch (NumberFormatException e) {
                e.printStackTrace();
            }

            return intValue;
        }
    }

    public static int getIntEncrypted(String key) {

        return AppPreferences.getIntEncrypted(key, 0);
    }

    public static boolean putBooleanEncrypted(String key, boolean value) {

        return AppPreferences.putStringEncrypted(key, Boolean.toString(value));
    }

    public static boolean getBooleanEncrypted(String key, boolean defaultValue) {

        String value = AppPreferences.getStringEncrypted(key, null);

        if(value == null) {

            return defaultValue;

        } else {

            boolean boolValue = defaultValue;

            try {

                boolValue = Boolean.parseBoolean(value);

            } catch (NumberFormatException e) {
                e.printStackTrace();
            }

            return boolValue;
        }
    }

    public static boolean getBooleanEncrypted(String key) {

        return AppPreferences.getBooleanEncrypted(key, false);
    }


    public static boolean putFloatEncrypted(String key, float value) {

        return AppPreferences.putStringEncrypted(key, Float.toString(value));
    }

    public static float getFloatEncrypted(String key, float defaultValue) {

        String value = AppPreferences.getStringEncrypted(key, null);

        if(value == null) {

            return defaultValue;

        } else {

            float floatValue = defaultValue;

            try {

                floatValue = Float.parseFloat(value);

            } catch (NumberFormatException e) {
                e.printStackTrace();
            }

            return floatValue;
        }
    }

    public static float getFloatEncrypted(String key) {

        return AppPreferences.getFloatEncrypted(key, 0);
    }

}

EncryptionUtils.java

import android.content.Context;
import android.provider.Settings;
import android.util.Base64;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;

/**
 * Created by vaibhav on 31/3/16.
 */
public class EncryptionUtils {

    protected static final String UTF8 = "utf-8";

    private static final char[] SEKRIT =  new char[] {'1', '2', '3', '4', '5','6'} ;

    // INSERT A RANDOM PASSWORD HERE.
    // Don't use anything you wouldn't want to
    // get out there if someone decompiled
    // your app.

    public static String encrypt(String value, Context context) {

        try {
            final byte[] bytes = value != null ? value.getBytes(UTF8) : new byte[0];
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWithMD5AndDES");
            SecretKey key = keyFactory.generateSecret(new PBEKeySpec(SEKRIT));
            Cipher pbeCipher = Cipher.getInstance("PBEWithMD5AndDES");
            pbeCipher.init(Cipher.ENCRYPT_MODE, key, new PBEParameterSpec(Settings.Secure.getString(context.getContentResolver(), Settings.System.ANDROID_ID).getBytes(UTF8), 20));
            return new String(Base64.encode(pbeCipher.doFinal(bytes), Base64.NO_WRAP), UTF8);

        } catch (Exception e) {
            throw new RuntimeException(e);
        }

    }

    public static String decrypt(String value, Context context) {
        try {
            final byte[] bytes = value != null ? Base64.decode(value, Base64.DEFAULT) : new byte[0];
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWithMD5AndDES");
            SecretKey key = keyFactory.generateSecret(new PBEKeySpec(SEKRIT));
            Cipher pbeCipher = Cipher.getInstance("PBEWithMD5AndDES");
            pbeCipher.init(Cipher.DECRYPT_MODE, key, new PBEParameterSpec(Settings.Secure.getString(context.getContentResolver(), Settings.System.ANDROID_ID).getBytes(UTF8), 20));
            return new String(pbeCipher.doFinal(bytes), UTF8);

        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

}