NetworkState

public class NetworkState {

    private static NetworkState sInstance = null;

    private boolean mConnected = false;
    private NetworkStateListener mListener;

    private NetworkState() {

    }

    public static NetworkState getInstance() {
        if (sInstance == null) {
            sInstance = new NetworkState();
        }
        return sInstance;
    }

    public void setConnected(boolean connected) {
        mConnected = connected;

        if (mListener != null) {
            mListener.onNetworkStateChanged(connected);
        }
    }

    public boolean isConnected() {
        return mConnected;
    }

    public void setListener(NetworkStateListener listener) {
        mListener = listener;
    }

    public interface NetworkStateListener {
        public void onNetworkStateChanged(boolean connected);
    }
}