android判断网络是否可用

public static boolean isNetworkAvailable(Context context) {
if(context != null){
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo mNetworkInfo = cm.getActiveNetworkInfo();
if (mNetworkInfo != null) {
return mNetworkInfo.isAvailable();
}
}
return false;
}