How to check internet access on Android? InetAddress never times out

Question

How to check internet access on Android? InetAddress never times out

I got a AsyncTask that is supposed to check the network access to a host name. But the doInBackground() is never timed out. Anyone have a clue?



public class HostAvailabilityTask extends AsyncTask<String, Void, Boolean> {



    private Main main;



    public HostAvailabilityTask(Main main) {

        this.main = main;

    }



    protected Boolean doInBackground(String... params) {

        Main.Log("doInBackground() isHostAvailable():"+params[0]);



        try {

            return InetAddress.getByName(params[0]).isReachable(30); 

        } catch (UnknownHostException e) {

            e.printStackTrace();

        } catch (IOException e) {

            e.printStackTrace();

        }

        return false;       

    }



    protected void onPostExecute(Boolean... result) {

        Main.Log("onPostExecute()");



        if(result[0] == false) {

            main.setContentView(R.layout.splash);

            return;

        }



        main.continueAfterHostCheck();

    }   

}

android java

3 years ago by akshay1995

2 Answers

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**espadacoder11** · Answer 1 · 2021-06-14T11:44:55

If the device is in airplane mode (or presumably in other situations where there's no available network), cm.getActiveNetworkInfo() will be null, so you need to add a null check.

Modified (Eddie's solution) below:



public boolean isOnline() {

    ConnectivityManager cm =

        (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

    NetworkInfo netInfo = cm.getActiveNetworkInfo();

    return netInfo != null && netInfo.isConnectedOrConnecting();

}

Also add the following permission to the AndroidManifest.xml:



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

One other small point, if you absolutely need a network connection at the given point in time, then it might be better to use netInfo.isConnected() rather than netInfo.isConnectedOrConnecting. I guess this is up to the individual use-case however.

**RoliMishra** · Answer 2 · 2021-06-15T14:00:03

No need to be complex. The simplest and framework manner is to use ACCESS_NETWORK_STATE permission and just make a connected method

public boolean isOnline() {

    ConnectivityManager cm =

        (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);



    return cm.getActiveNetworkInfo() != null && 

       cm.getActiveNetworkInfo().isConnectedOrConnecting();

}

You can also use requestRouteToHost if you have a particualr host and connection type (wifi/mobile) in mind.

You will also need:

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

in your android manifest.

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How to check internet access on Android? InetAddress never times out

2 Answers

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