Java代码：
public static boolean isNetworkAvailable(Context context)
{
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(
Context.CONNECTIVITY_SERVICE);
NetworkInfo info = cm.getActiveNetworkInfo();
return (info != null && info.isConnected());
}
public static boolean isNetworkAvailable(Context context)
{
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(
Context.CONNECTIVIT