Android是否联网判断

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>

ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(CONNECTIVITY_SERVICE）;
NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
if(networkInfo == null || !networkInfo.isAvailable())  {
//没有联网
}
else   {
//联网网络
}