Check Android device Iranian sim-card operator

IranSimCardUtil.java

package com.mirhoseini;

import android.content.Context;
import android.telephony.TelephonyManager;

public class IranSimCardUtil {

    public static String MCI_OPERATOR = "43211";
    // Telecommunication Kish
    public static String TKC_OPERATOR = "43214";
    // Mobile Telecommunications Company of Esfahan
    public static String MTCE_OPERATOR = "43219";
    public static String RIGHTEL_OPERATOR = "43220";
    public static String TALIYA_OPERATOR = "43232";
    public static String IRANCELL_OPERATOR = "43235";
    // Telecommunication Company of Iran
    public static String TCI_OPERATOR = "43270";
    static IranianSimCardOperators iranianSimCardOperators = null;

    /**
     * Check sim-card operator in Iran such as MTN-Irancell, MCI, Rightel, Taliya, ...
     *
     * @param context Context of application
     * @return
     */
    public static IranianSimCardOperators getSimCardOperator(Context context) {
        if (iranianSimCardOperators == null) {
            TelephonyManager manager = (TelephonyManager) context
                    .getSystemService(Context.TELEPHONY_SERVICE);

            if (checkSimExistence(context)) {
                String strSimOperator = manager.getSimOperator();
                if (strSimOperator.equals(MCI_OPERATOR))
                    iranianSimCardOperators = IranianSimCardOperators.MCI;
                else if (strSimOperator.equals(TKC_OPERATOR))
                    iranianSimCardOperators = IranianSimCardOperators.TKC;
                else if (strSimOperator.equals(MTCE_OPERATOR))
                    iranianSimCardOperators = IranianSimCardOperators.MTCE;
                else if (strSimOperator.equals(RIGHTEL_OPERATOR))
                    iranianSimCardOperators = IranianSimCardOperators.RIGHTEL;
                else if (strSimOperator.equals(TALIYA_OPERATOR))
                    iranianSimCardOperators = IranianSimCardOperators.TALIYA;
                else if (strSimOperator.equals(IRANCELL_OPERATOR))
                    iranianSimCardOperators = IranianSimCardOperators.IRANCELL;
                else if (strSimOperator.equals(TCI_OPERATOR))
                    iranianSimCardOperators = IranianSimCardOperators.TCI;
                else {
                    iranianSimCardOperators = IranianSimCardOperators.UNKNOWN;
                }
            } else {
                iranianSimCardOperators = null;
            }
        }
        return iranianSimCardOperators;
    }

    /**
     * Check if sim-card exist
     *
     * @param context Context of application
     * @return
     */
    public static boolean checkSimExistence(Context context) {
        TelephonyManager manager = (TelephonyManager) context
                .getSystemService(Context.TELEPHONY_SERVICE);
        return manager.getSimState() == TelephonyManager.SIM_STATE_READY ? true
                : false;
    }

    public enum IranianSimCardOperators {
        MCI, TKC, MTCE, TALIYA, IRANCELL, TCI, RIGHTEL, UNKNOWN
    }
    
}