Руководство по лицензированию Android -Последний шаг

Мое приложение уже готово к отправке, но недавно я узнал о лицензировании.

Я нашел пошаговое руководство в Интернете:http://twistbyte.com/tutorial/using-the-android-licensing-service-step-by-step

Я импортировал библиотеку лицензирования в Eclipse и создал класс LicenseCheckActivity, как описано в руководстве.

Я нахожусь на последнем шаге руководства, пункт номер 7. В руководстве сказано, что мой класс должен расширяться LicenseCheckActivity. Однако класс, в котором я хотел бы проверить лицензирование, уже расширяет Activity.

Как я могу использовать метод checkLicense()из моего класса LicenseCheckActivity?

Вот мой код:

protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.splash);

    // Check the license
    LicenseCheckActivity  l = new LicenseCheckActivity();
    checkLicense();

Это дает мне следующую ошибку:

Cannot instantiate the type LicenseCheckActivity

Вот мой LicenseCheckActivityкласс

public abstract class LicenseCheckActivity extends Activity {

static boolean licensed = true;
static boolean didCheck = false;
static boolean checkingLicense = false;
static final String BASE64_PUBLIC_KEY = "MY BASE KEY";

LicenseCheckerCallback mLicenseCheckerCallback;
LicenseChecker mChecker;

Handler mHandler;

SharedPreferences prefs;

// REPLACE WITH YOUR OWN SALT, THIS IS FROM EXAMPLE
private static final byte[] SALT = new byte[] { -46, 65, 30, -128, -103,
        -57, 74, -64, 51, 88, -95, -45, 77, -117, -36, -113, -11, 32, -64,
        89 };

private void displayResult(final String result) {
    mHandler.post(new Runnable() {
        public void run() {

            setProgressBarIndeterminateVisibility(false);

        }
    });
}

protected void doCheck() {

    didCheck = false;
    checkingLicense = true;
    setProgressBarIndeterminateVisibility(true);

    mChecker.checkAccess(mLicenseCheckerCallback);
}

protected void checkLicense() {

    Log.i("LICENSE", "checkLicense");
    mHandler = new Handler();

    // Try to use more data here. ANDROID_ID is a single point of attack.
    String deviceId = Settings.Secure.getString(getContentResolver(),
            Settings.Secure.ANDROID_ID);

    // Library calls this when it's done.
    mLicenseCheckerCallback = new MyLicenseCheckerCallback();
    // Construct the LicenseChecker with a policy.
    mChecker = new LicenseChecker(this, new ServerManagedPolicy(this,
            new AESObfuscator(SALT, getPackageName(), deviceId)),
            BASE64_PUBLIC_KEY);

    // mChecker = new LicenseChecker(
    // this, new StrictPolicy(),
    // BASE64_PUBLIC_KEY);

    doCheck();
}

protected class MyLicenseCheckerCallback implements LicenseCheckerCallback {

    public void allow() {
        Log.i("LICENSE", "allow");
        if (isFinishing()) {
            // Don't update UI if Activity is finishing.
            return;
        }
        // Should allow user access.
        displayResult(getString(R.string.allow));
        licensed = true;
        checkingLicense = false;
        didCheck = true;

    }

    public void dontAllow() {
        Log.i("LICENSE", "dontAllow");
        if (isFinishing()) {
            // Don't update UI if Activity is finishing.
            return;
        }
        displayResult(getString(R.string.dont_allow));
        licensed = false;
        // Should not allow access. In most cases, the app should assume
        // the user has access unless it encounters this. If it does,
        // the app should inform the user of their unlicensed ways
        // and then either shut down the app or limit the user to a
        // restricted set of features.
        // In this example, we show a dialog that takes the user to Market.
        checkingLicense = false;
        didCheck = true;

        showDialog(0);
    }

    public void applicationError(int errorCode) {
        Log.i("LICENSE", "error: " + errorCode);
        if (isFinishing()) {
            // Don't update UI if Activity is finishing.
            return;
        }
        licensed = false;
        // This is a polite way of saying the developer made a mistake
        // while setting up or calling the license checker library.
        // Please examine the error code and fix the error.
        String result = String.format(
                getString(R.string.application_error), errorCode);
        checkingLicense = false;
        didCheck = true;

        displayResult(result);
        // showDialog(0);
    }

    public void allow(int reason) {
        // TODO Auto-generated method stub

    }

    public void dontAllow(int reason) {
        // TODO Auto-generated method stub

    }

}

protected Dialog onCreateDialog(int id) {
    // We have only one dialog.
    return new AlertDialog.Builder(this)
           .setTitle(R.string.unlicensed_dialog_title)
           .setMessage(R.string.unlicensed_dialog_body)
           .setPositiveButton(R.string.buy_button,
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog,
                                int which) {
                            Intent marketIntent = new Intent(
                                    Intent.ACTION_VIEW,
                                    Uri.parse("http://market.android.com/details?id="
                                            + getPackageName()));
                            startActivity(marketIntent);
                            finish();
                        }
                    })
           .setNegativeButton(R.string.quit_button,
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog,
                                int which) {
                            finish();
                        }
                    })

           .setCancelable(false)
           .setOnKeyListener(new DialogInterface.OnKeyListener() {
                public boolean onKey(DialogInterface dialogInterface,
                        int i, KeyEvent keyEvent) {
                    Log.i("License", "Key Listener");
                    finish();
                    return true;
                }
            }).create();

}

@Override
protected void onDestroy() {
    super.onDestroy();
    if (mChecker != null) {
        Log.i("LIcense", "distroy checker");
        mChecker.onDestroy();
    }
}

}