how can i check net connection in android?

Question

i have developed one application in that i have to check whether net is connected or not i use following code but its not working. can any one resolve my problem. my code is

public class AbcActivity extends Activity {
    Button b;
    private static final String tag = null;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        b=(Button)findViewById(R.id.button1);
        b.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                netCheckin();
            }
        });
    }
        private void netCheckin() {

            try {

                ConnectivityManager nInfo = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
                nInfo.getActiveNetworkInfo().isConnectedOrConnecting();

                Log.d(tag, "Net avail:"
                        + nInfo.getActiveNetworkInfo().isConnectedOrConnecting());

                ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
                NetworkInfo netInfo = cm.getActiveNetworkInfo();
                if (netInfo != null && netInfo.isConnectedOrConnecting()) {
                   Toast.makeText(getApplicationContext(), "net on", Toast.LENGTH_LONG).show();
                    Log.d(tag, "Network available:true");

                } else {
                     Toast.makeText(getApplicationContext(), "net OFF", Toast.LENGTH_LONG).show();
                    Log.d(tag, "Network available:false");

                }

            } catch (Exception e) {
               Log.e("error",""+e);
            }
        }

    }

i have give the android:name="android.permission.ACCESS_NETWORK_STATE"/> in my manifest file in above code my problem is when net is enable or disable it gives same output as "net on" (toast message).

Answer 1

At the top of your onCreate method , use

if(!checkInternetConnection()){
            // network connnectivity error , show some dialog here and exit from the app 

        }

where

private boolean checkInternetConnection() {

            ConnectivityManager conMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
            // ARE WE CONNECTED TO THE NET
            if (conMgr.getActiveNetworkInfo() != null
                    && conMgr.getActiveNetworkInfo().isAvailable()
                    && conMgr.getActiveNetworkInfo().isConnected()) {

                return true;

            } else {
                Log.v("", "Internet Connection Not Present");
                return false;
            }
        }

Hope this wil help you.

Answer 2

I have done this in my application. To really check for net connection, try to ping or DNS resolve www.google.com :

• If the ping is successful, then you have Internet connection
• If not, you don't have Internet connection

@Waqas, that question doesn't deal with the situation of connected to router, but no Internet access because the ConnectivityManager doesn't distinguish between Network and Internet connection.

Answer 3

Just try the below code so that u can check whether there is internet connected or not. This code is working for me.Also u can check if the internet is connected through mobile then it is in roaming or not.

    int typeOfConnection = 0;
    //Gets the system service of the connectivity.
    ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo[] netInfo = connectivityManager.getAllNetworkInfo();

    //Checks whether the connectivity type is WIFI or MOBILE.
    for (NetworkInfo networkInfo : netInfo)
    {
        if (networkInfo.getTypeName().equalsIgnoreCase("WIFI"))
            if (networkInfo.isConnected()){
                                     typeOfConnection = 1;
                 Toast.makeText(getApplicationContext(), "net on", Toast.LENGTH_LONG).show();

            }
        if (networkInfo.getTypeName().equalsIgnoreCase("MOBILE"))
            if (networkInfo.isConnected()){
                                     typeOfConnection = 2;
                 Toast.makeText(getApplicationContext(), "net on", Toast.LENGTH_LONG).show();

            }
    }

    TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
    if(typeOfConnection== 2 && telephonyManager.isNetworkRoaming()){
        typeOfConnection = 3;
    }

    if(typeOfConnection == 0){
                Toast.makeText(getApplicationContext(), "net OFF", Toast.LENGTH_LONG).show();

    }

All the best

Answer 4

// check internet connectivity
public static boolean isNetworkAvailable(Context context) {

    boolean networkStatus;
    try {

        ConnectivityManager connectivityManager = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = connectivityManager
                .getActiveNetworkInfo();

        networkStatus = (activeNetworkInfo != null && activeNetworkInfo.isConnected()) ? true : false;

    } catch (Exception e) {

        e.printStackTrace();
        DinotaLogger.log(e, Level.SEVERE);
        networkStatus = false;

    }

    return networkStatus;
}

Please make sure to put in manifest file. If you are using an emulator to check this, press F8 to disable network access. This works fine with android 2.3.3 emulator.