如何在Android中超时AlertDialog？

public class MainActivity extends Activity {

    static final int TIME_OUT = 5000;

    static final int MSG_DISMISS_DIALOG = 0;

    private AlertDialog mAlertDialog;

    @Override
    protected void onCreate(Bundle savedInstanceStatE) {
        super.onCreate(savedInstanceStatE);
        setContentView(R.layout.activity_main);

        createDialog();
    }

    private Handler mHandler = new Handler() {
        public void handlemessage(android.os.message msg) {
            switch (msg.what) {
            case MSG_DISMISS_DIALOG:
                if (mAlertDialog != null && mAlertDialog.isShowing()) {
                    mAlertDialog.dismiss();
                }
                break;

            default:
                break;
            }
        }
    };

    private void createDialog() {
        AlertDialog.builder builder = new AlertDialog.builder(this);
        builder.setPositiveButton("OK",null)
            .setNegativeButton("cacel",null);
        mAlertDialog = builder.create();
        mAlertDialog.show();
        // dismiss dialog in TIME_OUT ms
        mHandler.sendEmptymessageDelayed(MSG_DISMISS_DIALOG,TIME_OUT);
    }
}