مشکل هنگام چک کردن نصب بودن کافه بازار

سلام من از کد زیر برای تست کردن اینکه کافه بازار روی گوشی نصب  هست یا خیر استفاده می کنم اما وقتی کافه بازار روی گوشی نصب نیست برنامه فورس force close میشه . لطفا راهنمایی بفرمایید مشکل کجاست تشکر

اینم لاگ و کد کامل برنامه 

FATAL EXCEPTION: main
                                                                       java.lang.RuntimeException: Unable to start activity ComponentInfo{ir.omidghasemi/ir.omidghasemi.Buy1}: java.lang.NullPointerException
                                                                           at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
                                                                           at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
                                                                           at android.app.ActivityThread.access$600(ActivityThread.java:123)
                                                                           at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
                                                                           at android.os.Handler.dispatchMessage(Handler.java:99)
                                                                           at android.os.Looper.loop(Looper.java:137)
                                                                           at android.app.ActivityThread.main(ActivityThread.java:4424)
                                                                           at java.lang.reflect.Method.invokeNative(Native Method)
                                                                           at java.lang.reflect.Method.invoke(Method.java:511)
                                                                           at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
                                                                           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
                                                                           at dalvik.system.NativeStart.main(Native Method)
                                                                        Caused by: java.lang.NullPointerException
                                                                           at ir.omidghasemi.golvajeh.Utils.IabHelper.startSetup(IabHelper.java:267)
                                                                           at ir.omidghasemi.golvajeh.Buy1.onCreate(Buy1.java:214)
                                                                           at android.app.Activity.performCreate(Activity.java:4465)
                                                                           at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
                                                                           at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
                                                                           at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
                                                                           at android.app.ActivityThread.access$600(ActivityThread.java:123)
                                                                           at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
                                                                           at android.os.Handler.dispatchMessage(Handler.java:99)
                                                                           at android.os.Looper.loop(Looper.java:137)
                                                                           at android.app.ActivityThread.main(ActivityThread.java:4424)
                                                                           at java.lang.reflect.Method.invokeNative(Native Method)
                                                                           at java.lang.reflect.Method.invoke(Method.java:511)
                                                                           at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
                                                                           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
                                                                           at dalvik.system.NativeStart.main(Native Method)

  

public class Buy1 extends AppCompatActivity {

    Button kharid;

    Dialog wdialog;

    TextView kharidtxt;

      public static final String PREFS_NAME = "MyPrefsFile33";

    // Debug tag, for logging
    static final String TAG = "mytag";

    // SKUs for our products: the premium upgrade (non-consumable)
    static final String SKU_PREMIUM = "sg12";

    // Does the user have the premium upgrade?
    boolean mIsPremium = false;

    // (arbitrary) request code for the purchase flow
    static final int RC_REQUEST = 10021;

    // The helper object
    IabHelper mHelper;
    IabHelper.OnIabPurchaseFinishedListener mPurchaseFinishedListener;
    IabHelper.QueryInventoryFinishedListener mGotInventoryListener;







    //public key

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.buy1);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);


        wdialog = new Dialog(Buy1.this);
        wdialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
        wdialog.setContentView(R.layout.wdialog);
        wdialog.show();
        wdialog.setCancelable(false);


        final ProgressBar pbar = (ProgressBar) wdialog.findViewById(R.id.bar);

        kharidtxt = (TextView) wdialog.findViewById(R.id.kharidtxt);
        final Typeface Homa = Typeface.createFromAsset(getAssets(), "fonts/Homa.ttf");

        kharidtxt.setTypeface(Homa);

        pbar.setVisibility(View.VISIBLE);

// Create a Handler instance on the main thread
        final Handler handler = new Handler();

// Create and start a new Thread
        new Thread(new Runnable() {
            public void run() {
                try{
                    Thread.sleep(3000);
                }
                catch (Exception e) { } // Just catch the InterruptedException

                // Now we use the Handler to post back to the main thread
                handler.post(new Runnable() {
                    public void run() {
                        // Set the View's visibility back on the main UI Thread
                        pbar.setVisibility(View.INVISIBLE);
                        wdialog.hide();
                    }
                });
            }
        }).start();












        kharid = (Button) findViewById(R.id.kharid);


        kharid.setText("خرید 500 سکه به قیمت پانصد تومان");
        final Typeface Homa1 = Typeface.createFromAsset(getAssets(), "fonts/Homa.ttf");

        kharid.setTypeface(Homa1);

        //retrieve Coin
         SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
           G.omid = settings.getInt("key_point", G.omid);
          Level4.pointer = settings.getString("key_pointer", Level4.pointer);

kharid.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {

        if (isPackageInstalled("com.farsitel.bazaar")) {
            // Bazar is installed
            try {
                mHelper.launchPurchaseFlow(Buy1.this, SKU_PREMIUM, RC_REQUEST, mPurchaseFinishedListener, "payload-string");
            }
            catch (Exception e) {
                e.printStackTrace();
                Toast.makeText(Buy1.this,
                        "Reopen App and Try Again", Toast.LENGTH_SHORT).show();
            }
        }
        else {
           
            // not installed
        }
    }
});

        String base64EncodedPublicKey = "MIHNMA0GCSqGSIb3DQEBAQUAA4G7ADCBtwKBrwC6gWT4meJSsSkcu9Qy5YLr/EyMAUOGLA6jmyySm0GAtabD1zKMSbDc1YSh7SDx/Kr4qM60T0iXXvkh4CvHfPmCjOqJ2ZlaBsLoZz9NtVsF3SyY0YbzbaEMKXZnw3L0UTrjSKhbDHWJohrUC/aEP3porcY0nmKYkXQr0W5WkCZfDPN+o9AWPchY70de8AkasQHKg/lP99BnbI4vVKgjWkKe7D64HQmsO2Ycbe53LkMCAwEAAQ==";

        mHelper = new IabHelper(Buy1.this, base64EncodedPublicKey);


        mGotInventoryListener = new IabHelper.QueryInventoryFinishedListener() {
            public void onQueryInventoryFinished(IabResult result, Inventory inventory) {
                Log.d(TAG, "Query inventory finished.");
                if (result.isFailure()) {
                    Log.d(TAG, "Failed to query inventory: " + result);
                    return;
                }
                else {
                    Log.d(TAG, "Query inventory was successful.");
                    // does the user have the premium upgrade?
                    mIsPremium = inventory.hasPurchase(SKU_PREMIUM);
                    if (mIsPremium){
                        MasrafSeke(inventory.getPurchase(SKU_PREMIUM));
                    }
                    // update UI accordingly

                    Log.d(TAG, "User is " + (mIsPremium ? "PREMIUM" : "NOT PREMIUM"));
                }

                Log.d(TAG, "Initial inventory query finished; enabling main UI.");
            }
        };

        mPurchaseFinishedListener = new IabHelper.OnIabPurchaseFinishedListener() {
            public void onIabPurchaseFinished(IabResult result, Purchase purchase) {
                if (result.isFailure()) {
                    Log.d(TAG, "Error purchasing: " + result);
                    Toast.makeText(Buy1.this, "خرید ناموفق بود", Toast.LENGTH_SHORT).show();
                    return;
                }
                else if (purchase.getSku().equals(SKU_PREMIUM)) {
                    // give user access to premium content and update the UI

                    Toast.makeText(Buy1.this,"خرید موفق",Toast.LENGTH_SHORT).show();


                    MasrafSeke(purchase);


                }
            }
        };


        Log.d(TAG, "Starting setup.");
        mHelper.startSetup(new IabHelper.OnIabSetupFinishedListener() {
            public void onIabSetupFinished(IabResult result) {
                Log.d(TAG, "Setup finished.");

                if (!result.isSuccess()) {
                    // Oh noes, there was a problem.
                    Log.d(TAG, "Problem setting up In-app Billing: " + result);
                }
                // Hooray, IAB is fully set up!
                mHelper.queryInventoryAsync(mGotInventoryListener);
            }
        });



    }// oncreate









    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        Log.d(TAG, "onActivityResult(" + requestCode + "," + resultCode + "," + data);

        // Pass on the activity result to the helper for handling
        if (!mHelper.handleActivityResult(requestCode, resultCode, data)) {
            super.onActivityResult(requestCode, resultCode, data);
        } else {
            Log.d(TAG, "onActivityResult handled by IABUtil.");
        }
    }


    @Override
    public void onDestroy() {
        //از سرویس در زمان اتمام عمر activity قطع شوید
        super.onDestroy();
        if (mHelper != null) mHelper.dispose();
        mHelper = null;
    }


    private void MasrafSeke(Purchase kala){
        // برای اینکه کاربر فقط یکبار بتواند از کالای فروشی استفاده کند
        // باید بعد از خرید آن کالا را مصرف کنیم
        // در غیر اینصورت کاربر با یکبار خرید محصول می تواند چندبار از آن استفاده کند
        mHelper.consumeAsync(kala, new IabHelper.OnConsumeFinishedListener() {
            @Override
            public void onConsumeFinished(Purchase purchase, IabResult result) {
                if (result.isSuccess())

                    G.omid = G.omid + 500;
                Level4.pointer = String.valueOf(G.omid);
                Level4.point.setText(Level4.pointer);
                SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
                SharedPreferences.Editor editor = settings.edit();
                editor.putInt("key_point", G.omid);
                editor.putString("key_pointer", Level4.pointer);

                // Commit the edits!

                editor.commit();
                Toast.makeText(Buy1.this, "خرید 500 سکه با موفقیت انجام شد", Toast.LENGTH_SHORT).show();
                finish();

                Log.d(TAG, "NATIJE masraf: " + result.getMessage() + result.getResponse());

            }
        });
    }

    public boolean isPackageInstalled(String PackageName) {
        PackageManager manager = getPackageManager();
        boolean isAppInstalled = false;
        try {
            manager.getPackageInfo(PackageName, PackageManager.GET_ACTIVITIES);
            isAppInstalled = true;
        }
        catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
        return isAppInstalled;
    }


}