Develop Reference

Perform network operation to check if user has internet connection with async task

I am getting below exception
android.os.NetworkOnMainThreadException
because I don't use an async task to make the particular network operation. I have searched for this, but it got me so confused. Could someone make it work with async task and the particular functions?
Below are two functions i use :
1) isNetworkAvailable()
private boolean isNetworkAvailable() {
ConnectivityManager connectivityManager
= (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
return activeNetworkInfo != null;
}
2) hasInternetAccess(Boolean showMessage)
When i want to display a toast i call this function, setting the parameter to true.
public boolean hasInternetAccess(Boolean showMessage) {
if (isNetworkAvailable()) {
try {
HttpURLConnection urlc = (HttpURLConnection)
(new URL("http://clients3.google.com/generate_204")
.openConnection());
urlc.setRequestProperty("User-Agent", "Android");
urlc.setRequestProperty("Connection", "close");
urlc.setConnectTimeout(1500);
urlc.connect();
return (urlc.getResponseCode() == 204 &&
urlc.getContentLength() == 0);
} catch (IOException e) {
Log.w("connection", "Error checking internet connection", e);
}
} else {
if(showMessage) // If i want to show the toast, it's true
showAToast("No Internet Connection", Toast.LENGTH_SHORT); // Just another function to show a toast
}
return false;
}

This is how you can use an AsyncTask by creating an inner class which extends AsyncTask.
private class NetworkInAsync extends AsyncTask<String, Void, Boolean> {
private Context context;
private Activity activity;
NetworkInAsync(Activity activity) {
this.context = activity.getApplicationContext();
this.activity = activity;
}
#Override
protected void onPreExecute() {
}
#Override
protected void onPostExecute(Boolean result) {
// Do something with the result here
}
#Override
protected Boolean doInBackground(String... params) {
if (isNetworkAvailable()) {
try {
HttpURLConnection urlc = (HttpURLConnection)
(new URL("http://clients3.google.com/generate_204")
.openConnection());
urlc.setRequestProperty("User-Agent", "Android");
urlc.setRequestProperty("Connection", "close");
urlc.setConnectTimeout(1500);
urlc.connect();
return (urlc.getResponseCode() == 204 &&
urlc.getContentLength() == 0);
} catch (IOException e) {
Log.w("connection", "Error checking internet connection", e);
}
} else {
if(showMessage) // If i want to show the toast, it's true
showAToast("No Internet Connection", Toast.LENGTH_SHORT); // Just another function to show a toast
}
return false;
}
}
You can execute the AsyncTask as follows
new NetworkInAsync(this).execute();
I would still recommend you go through the docs here to clarify yourself how AsyncTask works in Android.

The code should work when you call it from AsyncTask's doInBackground method
call test();
private void test() {
HttpURLConnection urlc = (HttpURLConnection)
(new URL("http://clients3.google.com/generate_204")
.openConnection());
urlc.setConnectTimeout(1500);
urlc.connect();
}
You can check the network connection before making the call, but any how, you should catch the exception in TimeOut exception. So I dont think, that you have any much benifit to check the connectivity before making the call.

How to check internet connection before app starts and while it is running?

I found a lot of answer about this but unable to implement those also.
I want to implement this code here but not able to do so.
This code I found on google documentation.
ConnectivityManager cm =
(ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
boolean isConnected = activeNetwork != null &&
activeNetwork.isConnectedOrConnecting();
https://developer.android.com/training/monitoring-device-state/connectivity-monitoring.html#DetermineConnection
public class JSONfunctions {
public static JSONObject getJSONfromURL(String url) {
InputStream is = null;
String result = "";
JSONObject jArray = null;
// Download JSON data from URL
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection " + e.toString());
}
// Convert response to string
try {
BufferedReader reader = null;
if (is != null) {
reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
}
StringBuilder sb = new StringBuilder();
String line;
if (reader != null) {
while ((line = reader.readLine()) != null) {
sb.append(line).append("\n");
}
}
if (is != null) {
is.close();
}
result = sb.toString();
} catch (Exception e) {
Log.e("log_tag", "Error converting result " + e.toString());
}
try {
jArray = new JSONObject(result);
} catch (JSONException e) {
Log.e("log_tag", "Error parsing data " + e.toString());
}
return jArray;
}
}

UPDATE:
Update the solution for internet checking. What works for me now is this
fun isNetworkAvailable(context: Context?): Boolean {
if (context == null) return false
val connectivityManager =
context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
val capabilities =
connectivityManager.getNetworkCapabilities(connectivityManager.activeNetwork)
return capabilities != null &&
(capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) ||
capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) ||
capabilities.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET))
} else {
try {
val activeNetworkInfo = connectivityManager.activeNetworkInfo
return activeNetworkInfo != null && activeNetworkInfo.isConnected
} catch (ignored: Exception) {
}
}
return false
}
OLD:
Simple function to check the internet connection
protected boolean isOnline() {
ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netInfo = cm.getActiveNetworkInfo();
if (netInfo != null && netInfo.isConnected()) {
return true;
} else {
return false;
}
}
and in your AndroidManifest.xml you should add the permission
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

protected boolean isNetworkAvilable() {
boolean isNetworkAvilable = false;
ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo info = manager.getActiveNetworkInfo();
if (info != null && info.isAvailable() && info.isConnected()) {
isNetworkAvilable = true;
}
return isNetworkAvilable;
}
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

public static boolean isNetworkAvailable(Context context) {
ConnectivityManager cm = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
if (activeNetwork != null) {
if (activeNetwork.getType() == ConnectivityManager.TYPE_WIFI) {
return true;
} else if (activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE) {
return true;
}
}
return false;
}

like this you can make this method in your common file for your project
public static boolean isNetworkAvailable(Context ctx) {
ConnectivityManager cm = (ConnectivityManager) ctx
.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netInfo = cm.getActiveNetworkInfo();
if (netInfo != null && netInfo.isConnectedOrConnecting()
&& cm.getActiveNetworkInfo().isAvailable()
&& cm.getActiveNetworkInfo().isConnected()) {
return true;
} else {
return false;
}
}
and use like
if(commonfile.isNetworkAvilable(pass your context here))
{
//call your method
}
and don't forgot to add permission for Internet in your manifeast

what happens if your device connected to internet, but no input data? You also have to check whether you are receiving data or not. Check below code to see you are connected internet and able access data. You just need to ping a site and see if your responce back is 200.
public class internetchek extends AsyncTask<Void,Void,Void> {
public boolean connection;
Context ctx;
public internetchek(Context context){
this.ctx = context;
}
public internetchek(){
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected Void doInBackground(Void... params) {
if(isNetworkAvailable(this.ctx))
{
Log.d("NetworkAvailable","TRUE");
if(connectGoogle())
{
Log.d("GooglePing","TRUE");
connection=true;
}
else
{
Log.d("GooglePing","FALSE");
connection=false;
}
}
else {
connection=false;
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
}
public static boolean isNetworkAvailable(Context context) {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netInfo = cm.getActiveNetworkInfo();
if (netInfo != null && netInfo.isConnected()) {
return true;
}
return false;
}
public static boolean connectGoogle() {
try {
HttpURLConnection urlc = (HttpURLConnection) (new URL("http://www.google.com").openConnection());
urlc.setRequestProperty("User-Agent", "Test");
urlc.setRequestProperty("Connection", "close");
urlc.setConnectTimeout(10000);
urlc.connect();
return (urlc.getResponseCode() == 200);
} catch (IOException e) {
Log.d("GooglePing","IOEXCEPTION");
e.printStackTrace();
return false;
}
}
UPDATE: If you want to use it for other classes you can do this..make sure you put below code in AsyncTask or background running thread.
if(internetchek.isNetworkAvailable(this.ctx)||internetchek.connectGoogle())
{
//Do your stuff here. when you have internet access
}

How to make a ping in Android to Google

I'm trying to find the way to know when an user has Internet connection, since now I've got this method :
public boolean isNetworkOnline() {
boolean status=false;
try{
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netInfo = cm.getNetworkInfo(1);
if (netInfo != null && netInfo.getState()==NetworkInfo.State.CONNECTED) {
status= true;
}
}catch(Exception e){
e.printStackTrace();
return false;
}
return status;
}
This method returns true if user is CONNECTED but not if user has INTERNET CONNECTION, so I thought to if this method returns true, call another method to check if the user has connection to internet. For example someone can be connected to a router but without internet connection so I want to know when the user has internet connection or not.
I've read this answer and this other but all of them is returning me false when I've got Internet connection.... I thought that make a method that makes a ping to www.google.com it's a good approach to know if someone has internet connection so I tried to get this way but it didn't work for me...
Any idea or good approach (if it's better than my thoughts is better) to know when the user has internet connection?

The Simple Way To Check Internet Connectivity
public boolean isConnectingToInternet() {
if (networkConnectivity()) {
try {
Process p1 = Runtime.getRuntime().exec(
"ping -c 1 www.google.com");
int returnVal = p1.waitFor();
boolean reachable = (returnVal == 0);
if (reachable) {
System.out.println("Internet access");
return reachable;
} else {
return false;
}
} catch (Exception e) {
return false;
}
} else
return false;
}
private boolean networkConnectivity() {
ConnectivityManager cm = (ConnectivityManager) _context
.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = cm.getActiveNetworkInfo();
return networkInfo != null && networkInfo.isConnected();
}
How To Call it
if (isConnectingToInternet()) {
// internet is connected and work properly...
}
else {
// something went wrong internet not working properly...
}
So simply copy and past the above two methods where you want to check the Internet connectivity. After that check the condition if (isConnectingToInternet()) { }

Can you try this method?
public boolean checkInternectConnection() {
try {
InetAddress inAddress= InetAddress.getByName("http://google.com");
if (inAddress.equals("")) {
return false;
} else {
return true;
}
} catch (Exception e) {
return false;
}
}

Please check this answer out and see if its helpful or not
You can try out this code
try {
URL url = new URL("http://"+params[0]);
HttpURLConnection urlc = (HttpURLConnection) url.openConnection();
urlc.setRequestProperty("User-Agent", "Android Application:"+Z.APP_VERSION);
urlc.setRequestProperty("Connection", "close");
urlc.setConnectTimeout(1000 * 30); // mTimeout is in seconds
urlc.connect();
if (urlc.getResponseCode() == 200) {
Main.Log("getResponseCode == 200");
return new Boolean(true);
}
} catch (MalformedURLException e1) {
e1.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}

this is how i fixed this and i use it as a Utility method which can be called from any activity/fragment etc...:
public static boolean isNetworkAvailable(Context context) {
ConnectivityManager connectivityManager
= (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}//check if Wifi or Mobile data is enabled
private static class NetworkAsync extends AsyncTask<Void, Void, Boolean> {
#Override
protected Boolean doInBackground(Void... voids) {
try {
HttpURLConnection urlConnection = (HttpURLConnection)
(new URL("http://clients3.google.com/generate_204")
.openConnection());
urlConnection.setRequestProperty("User-Agent", "Android");
urlConnection.setRequestProperty("Connection", "close");
urlConnection.setConnectTimeout(1500);
urlConnection.connect();
return (urlConnection.getResponseCode() == 204 &&
urlConnection.getContentLength() == 0);
} catch (IOException e) {
// Error checking internet connection
}
return false;
}
}//network calls shouldn't be called from main thread otherwise it will throw //NetworkOnMainThreadException
and now you simply need to call this method from anywhere you want:
public static boolean checkInternetConnection(Context context) {
if (isNetworkAvailable(context)) {
try {
//used execute().get(); so that it gets awaited and returns the result
//after i receive a response
return new NetworkAsync().execute().get();
} catch (ExecutionException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
return false;
}

ANDROID Check condition for server down

My app needs to check for internet access which I successfully implemented.
But I have a condition that internet is available but website it is trying to open is currently down.
In this case I need to show different message as an output.
How can I do so? Please give some idea.

public boolean isServerReachable()
// To check if server is reachable
{
try {
InetAddress.getByName("google.com").isReachable(3000); //Replace with your name
return true;
} catch (Exception e) {
return false;
}
}

You should check the status of the website's response Like this:
HttpResponse response = httpClient.execute(request);
int status = response.getStatusLine().getStatusCode();
and check here to find your status code.
then you can do your job by checking status code like this:
if (status == 200) // sucess
{
also I recommend you to use AsyncTask for your connection to do communication with server in background.

Try to catch NoHttpResponseException as follow
try{
//code to try to connect to your server
}catch(NoHttpResponseException ex){
//print stacktrace or display some message to say server is down
}

You can use this class. Make object and call methods.
public class ConnectionDetector {
private Context context;
public ConnectionDetector(Context context){
this.context = context;
}
public boolean isConnectingToInternet(){
ConnectivityManager connectivity = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectivity != null)
{
NetworkInfo[] info = connectivity.getAllNetworkInfo();
if (info != null)
for (int i = 0; i < info.length; i++)
if (info[i].getState() == NetworkInfo.State.CONNECTED)
{
return true;
}
}
return false;
}
public boolean isURLReachable() {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netInfo = cm.getActiveNetworkInfo();
if (netInfo != null && netInfo.isConnected()) {
try {
URL url = new URL(serverConnection.url); // Insert Url
HttpURLConnection urlc = (HttpURLConnection) url.openConnection();
urlc.setConnectTimeout(10 * 1000); // 10 s.
urlc.connect();
if (urlc.getResponseCode() == 200) { // 200 = "OK" code (http connection is fine).
Log.wtf("Connection", "Success !");
return true;
} else {
return false;
}
} catch (MalformedURLException e1) {
return false;
} catch (IOException e) {
return false;
}
}
return false;
}
}

How to check server connection is available or not in android

Testing of Network Connection can be done by following method:
public boolean isNetworkAvailable()
{
ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = cm.getActiveNetworkInfo();
if (networkInfo != null && networkInfo.isConnected())
{
return true;
}
return false;
}
But i don't know how to check the server connection.I had followed this method
public boolean isConnectedToServer(String url, long timeout) {
try{
URL myUrl = new URL(url);
URLConnection connection = myUrl.openConnection();
connection.setConnectTimetout(timeout);
connection.connect();
return true;
} catch (Exception e) {
// Handle your exceptions
return false;
}
}
it doesn't works....Any Ideas Guys!!

you can check a server connection is available or not using isReachable():
netAddress address = InetAddress.getByName(HOST_NAME);
boolean reachable = address.isReachable(timeout);
and by using runtime:
Runtime runtime = Runtime.getRuntime();
Process proc = runtime.exec("ping www.google.com");

public boolean isConnectedToServer(String url, int timeout) {
try{
URL myUrl = new URL(url);
URLConnection connection = myUrl.openConnection();
connection.setConnectTimeout(timeout);
connection.connect();
return true;
} catch (Exception e) {
// Handle your exceptions
return false;
}
}
and also add intent permission in your manifest
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />