네트워크 상태 체크 코드

public boolean checkNetwokState() {
  ConnectivityManager manager = 
     (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
  NetworkInfo mobile = manager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
  NetworkInfo wifi = manager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
  NetworkInfo lte_4g = manager.getNetworkInfo(ConnectivityManager.TYPE_WIMAX); //LTE
  boolean blte_4g = false;
  if(lte_4g != null)                             
   blte_4g = lte_4g.isConnected();
  if (mobile.isConnected() || wifi.isConnected() || blte_4g)
        return true;
  else {
   AlertDialog.Builder dlg = new AlertDialog.Builder(IntroActivity.this);
   dlg.setTitle("네트워크 오류");
   dlg.setMessage("네트워크 상태를 확인해 주십시요.");
   dlg.setIcon(R.drawable.icon36);
   dlg.setNegativeButton("종료", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog, int whichButton) {      
     finish();  // 끝내버렷
    } 
   });
   dlg.setCancelable(false);
   dlg.show();
   return false;
  }
 }