android网络判断

//ConnectivityManager管理网络连接相关的操作

ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); 

// 获取代表联网状态的NetWorkInfo对象   
NetworkInfo activeNetInfo = connectivityManager.getActiveNetworkInfo();

//activeNetInfo对象不能为空

 if(activeNetInfo!=null){

//判断是wifi还是手机网络
         if(activeNetInfo.getType()==ConnectivityManager.TYPE_MOBILE){
          switch (activeNetInfo.getSubtype()) {
    case TelephonyManager.NETWORK_TYPE_GPRS:
     //联通2g
     break;
    case TelephonyManager.NETWORK_TYPE_CDMA:
     //电信2g
    break;
    case TelephonyManager.NETWORK_TYPE_EDGE:
     //移动2g
     break;
    default:
     break;
    }
         }

//判断是否有网络
        boolean notewoke = activeNetInfo.isAvailable();
        if(notewoke){
         Log.e("网络可用", "网络可用");
         return true;
        }else{
         Log.e("网络可用", "网络不bu可用");
          return false;
        }
        }else{
         Log.e("网络可用", "网络不bu可用");
         return false;
        }
 }