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

4 years ago by akshay1995

2 Answers

Login / Signup to Answer the Question.

Login Signup

**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.

C TUTORIAL

C PROGRAMS

INTERVIEW TESTS

EXECUTE CODE

C++ TUTORIAL

C++ PROGRAMS

INTERVIEW TESTS

EXECUTE CODE

PYTHON TUTORIAL

PYTHON HOW TOS

INTERVIEW TESTS

EXECUTE CODE

JAVA TUTORIAL

JAVA CODE EXAMPLES

SPRING TUTORIAL

MORE IN JAVA

COMPUTER ARCHITECTURE

COMPUTER NETWORK

OPERATING SYSTEM

DBMS & SQL

PL/SQL

MongoDB

EXECUTE SQL

ANDROID DEVELOPMENT

GO LANGUAGE

LINUX

DOCKER

HTML TAGS (A to Z)

CSS REFERENCES

SASS/SCSS

KOTLIN

GAME DEVELOPMENT

PHP

GIT GUIDE

JAVASCRIPT

ADVANCED DSA

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

2 Answers

Login / Signup to Answer the Question.