Develop Reference

Android: Checking network connectivity return not connected when connected to wifi/3g in Broadcast receiver

I want to check if device in connected or not in broadcastReceiver.
below is my code :
public boolean isOnline(Context context) {
NetworkInfo info = (NetworkInfo) ((ConnectivityManager) context
.getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo();
if (info == null || !info.isConnected()) {
Log.e("UpdateDataReceiver","info: "+info);
return false;
}
return true;
}
Issue with my code:
above function returns me false (even when wifi connected) when BroadcastReceiver fires in background(when app is in background)
and it returns true when app is in foreground.
info: NetworkInfo: type: WIFI[], state: DISCONNECTED/BLOCKED, reason:
(unspecified), extra: (none), roaming: false, failover: false,
isAvailable: true, isConnectedToProvisioningNetwork: false, simId: 0
Device Info: Redmi Note

This is how I'm handling it as it turns out getActiveNetworkInfo will always return you DISCONNECTED/BLOCKED in a specific case even if there is network connection. This is the receive method in the BroadcastReceiver with intent filter ConnectivityManager.CONNECTIVITY_ACTION.
#Override
public void onReceive(Context context, Intent intent) {
ConnectivityManager conn = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = conn.getActiveNetworkInfo();
NetworkInfo intentNetworkInfo = intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);
if (intentNetworkInfo == null) {
intentNetworkInfo = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
}
if (networkInfo == null) {
networkInfo = intentNetworkInfo;
} else {
//when low battery get ActiveNetwork might receive DISCONNECTED/BLOCKED but the intent data is actually CONNECTED/CONNECTED
if (intentNetworkInfo != null && networkInfo.isConnectedOrConnecting() != intentNetworkInfo.isConnectedOrConnecting()) {
networkInfo = intentNetworkInfo;
}
}
//do something with networkInfo object
}
I've searched for better solution but no results. The case I've been able to reproduce 100% on my device (Pixel 7.1.2) is the following:
The device must be on low battery < 15% (other devices <20%)
Wifi is on, app is launched
Send app to background turnoff wifi and go to 3g (or vice versa)
Go back to the app
In that situation the app will report DISCONNECTED/BLOCKED from getActiveNetworkInfo.
If you change connectivity while in app it will be ok but if it is on background it wont. This won't happen while you are debugging because it will be charging the device even if the battery is low.
In the example above EXTRA_NETWORK_INFO in ConnectivityManager and WifiManager is actually same string "networkInfo" but I didn't wan't to risk it if in other Android versions they are different, so it is extra boilerplate.
You can directly use the networkInfo from the intent but I wanted to show here that there is a case where actualNetworkInfo is not the actual network info.

I believe the way you can do this is,
Register a Broadcast Receiver with an IntentFilter of ConnectivityManger.Connectivity_Action
private BroadcastReceiver receiverDataChange;
private void registerData(){
try {
receiverDataChange = new bcr_ToggleData();
IntentFilter filterData = new IntentFilter();
filterData.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
registerReceiver(receiverDataChange, filterData);
} catch (IllegalArgumentException e) {
e.printStackTrace();
}}
Then in your Broadcast receiver class
public class bcr_ToggleData extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
int state = telephonyManager.getDataState();
switch (state){
case TelephonyManager.DATA_DISCONNECTED: // off
Log.d("DavidJ", "DISCONNECTED");
break;
case TelephonyManager.DATA_CONNECTED: // on
Log.d("DavidJ", "CONNECTED");
break;
}
}
}
}
This fires off when you go into your settings and turn on/off mobile data.
Hope this helps! :)

ConnectivityManager cm =
(ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
boolean isConnected = activeNetwork != null &&
activeNetwork.isConnectedOrConnecting();
I found this on this google tutorial: http://developer.android.com/intl/pt-br/training/monitoring-device-state/connectivity-monitoring.html. check it out.

checking Network Status while running the app in android

I am streaming a video by using some url. Here, when i started the application I have checked the network status, or when i came to onResume state, i checked the Network status. But , while streaming is playing, If any cause net work will fail.. How can i check the status of the Network.
Here i am using this code for check the status..
public static boolean isOnline(Context context) {
boolean state = false;
ConnectivityManager cm = (ConnectivityManager)
context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo wifiNetwork =
cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
if (wifiNetwork != null) {
state=wifiNetwork.isConnectedOrConnecting();
}
NetworkInfo mobileNetwork =
cm.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
if (mobileNetwork != null) {
state=mobileNetwork.isConnectedOrConnecting();
}
NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
if (activeNetwork != null) {
state=activeNetwork.isConnectedOrConnecting();
}
return state;
}
from oncreate and orResume method, i was calling this method.. But how can i find the status of Network while running the app.
Thanks in advance...

You can register a BroadcastReceiver inside your Activity, that will receive the connectivity change broadcast. So inside the onReceive() method, that will be triggered when there will be a change in your connectivity, you will have to take actions :
BroadcastReceiver mNetworkReceiver=new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
//take actions
}
};
registerReceiver(mNetworkReceiver,
new IntentFilter("android.net.conn.CONNECTIVITY_CHANGE"));
You will also need to add the following permission to your manifest :
<uses-permission
android:name="android.permission.ACCESS_NETWORK_STATE" />

Network checking functionality in android?

I use the following code to check the network availability while hitting remote service or accessing any web pages, for that i will call this below method every time before hitting web service, but i need any monitor which periodically monitor the web service at background and throw an alert network is not available, and if network is resume it net to throw an alert network is resumed , i don`t know how to achieve it.
public boolean isOnline(Context context)
{
boolean state=false;
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo wifiNetwork = cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
if (wifiNetwork != null) {
state=wifiNetwork.isConnectedOrConnecting();
}
NetworkInfo mobileNetwork = cm.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
if (mobileNetwork != null) {
state=mobileNetwork.isConnectedOrConnecting();
}
NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
if (activeNetwork != null) {
state=activeNetwork.isConnectedOrConnecting();
}
return state;
}

For that you need to implement the broadcast receiver, it will check the network connection in background and give alert when network has connectivity or not.
Please try below code.
1) Make one class which will extend brodcast receiver.
public class CheckInternetConnectionChangeReceiver extends BroadcastReceiver
{
public static boolean connectionStatus = false;
#Override
public void onReceive(Context context, Intent intent)
{
connectionStatus = CheckInternetConnection(context);
if(connectionStatus)
Toast.makeText(context, "Internet Connection Available", Toast.LENGTH_LONG).show();
else
Toast.makeText(context, "Internet Connection Not Available", Toast.LENGTH_LONG).show();
}
public boolean CheckInternetConnection(Context context)
{
ConnectivityManager connec = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
android.net.NetworkInfo wifi = connec.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
android.net.NetworkInfo mobile = connec.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
if (wifi.isConnected())
{
return true;
}
else if (!mobile.isConnected())
{
return false;
}
else if (mobile.isConnected())
{
return true;
}
return false;
}
}
// Here connectionStatus is a one boolean variable which stored the true or false value according to network . If it is available it will stored true value other wise it will stored false value.
Now Paste below code in your android manifest file.
<receiver android:name=".CheckInternetConnectionChangeReceiver">
<intent-filter>
<action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
</intent-filter>
</receiver>
Now when ever connection change it will call the brodcast receiver and store the appropriate value in the connnectionStatus variable.

Here is an effective way of checking for an active connection: http://yue-gao.blogspot.com/2010/12/android-effective-way-to-test-internet.html

How to detect when WIFI Connection has been established in Android?

I need to detect when I have network connectivity over WIFI. What broadcast is sent to establish that a valid network connection has been made. I need to validate that a valid network connection for HTTP exists. What should I listen for and what additional tests do I need to make to know that a valid connection exists.

You can register a BroadcastReceiver to be notified when a WiFi connection is established (or if the connection changed).
Register the BroadcastReceiver:
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION);
registerReceiver(broadcastReceiver, intentFilter);
And then in your BroadcastReceiver do something like this:
#Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
if (action.equals(WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION)) {
if (intent.getBooleanExtra(WifiManager.EXTRA_SUPPLICANT_CONNECTED, false)) {
//do stuff
} else {
// wifi connection was lost
}
}
}
For more info, see the documentation for BroadcastReceiver and WifiManager
Of course you should check whether the device is already connected to WiFi before this.
EDIT:
Thanks to ban-geoengineering, here's a method to check whether the device is already connected:
private boolean isConnectedViaWifi() {
ConnectivityManager connectivityManager = (ConnectivityManager) appObj.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo mWifi = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
return mWifi.isConnected();
}

The best that worked for me:
AndroidManifest
<receiver android:name="com.AEDesign.communication.WifiReceiver" >
<intent-filter android:priority="100">
<action android:name="android.net.wifi.STATE_CHANGE" />
</intent-filter>
</receiver>
BroadcastReceiver class
public class WifiReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
NetworkInfo info = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
if(info != null && info.isConnected()) {
// Do your work.
// e.g. To check the Network Name or other info:
WifiManager wifiManager = (WifiManager)context.getSystemService(Context.WIFI_SERVICE);
WifiInfo wifiInfo = wifiManager.getConnectionInfo();
String ssid = wifiInfo.getSSID();
}
}
}
Permissions
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

For me only WifiManager.NETWORK_STATE_CHANGED_ACTION works.
Register a broadcast receiver:
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
registerReceiver(broadcastReceiver, intentFilter);
and receive:
#Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
if(action.equals(WifiManager.NETWORK_STATE_CHANGED_ACTION)){
NetworkInfo info = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
boolean connected = info.isConnected();
//call your method
}
}

You can start a wifi connection if you give the user a choice to override the normal behavior of asking each time.
I choose to use three methods...
public boolean isOnline()
{
ConnectivityManager connMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
return (networkInfo != null && networkInfo.isConnected());
}
This is quick check if there is an internet connect either Wifi or CellData. From here you can choose what action you want to take. Is it in Airplane mode needs to be checked also.
On a separate thread.
I set a variable IpAddress to = " "
And poll until I have a valid an ip address.
WifiManager wifi;
wifi = (WifiManager) this.getSystemService(Context.WIFI_SERVICE);
WifiInfo wifiInfo = wifi.getConnectionInfo();
int ipAddress = wifiInfo.getIpAddress();
String ip = null;
ip = String.format("%d.%d.%d.%d",
(ipAddress & 0xff),
(ipAddress >> 8 & 0xff),
(ipAddress >> 16 & 0xff),
(ipAddress >> 24 & 0xff));
Log.e(" >>IP number Begin ",ip);
Another code snippet... If its not on turn it on (with users prior permission)
if(wifi.isWifiEnabled()!=true)wifi.setWifiEnabled(true);

Answer given by user #JPM and #usman are really very useful. It works fine but in my case it come in onReceive multiple time in my case 4 times so my code execute multiple time.
I do some modification and make as per my requirement and now it comes only 1 time
Here is java class for Broadcast.
public class WifiReceiver extends BroadcastReceiver {
String TAG = getClass().getSimpleName();
private Context mContext;
#Override
public void onReceive(Context context, Intent intent) {
mContext = context;
if (intent.getAction().equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = cm.getActiveNetworkInfo();
if (networkInfo != null && networkInfo.getType() == ConnectivityManager.TYPE_WIFI &&
networkInfo.isConnected()) {
// Wifi is connected
WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
WifiInfo wifiInfo = wifiManager.getConnectionInfo();
String ssid = wifiInfo.getSSID();
Log.e(TAG, " -- Wifi connected --- " + " SSID " + ssid );
}
}
else if (intent.getAction().equalsIgnoreCase(WifiManager.WIFI_STATE_CHANGED_ACTION))
{
int wifiState = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE, WifiManager.WIFI_STATE_UNKNOWN);
if (wifiState == WifiManager.WIFI_STATE_DISABLED)
{
Log.e(TAG, " ----- Wifi Disconnected ----- ");
}
}
}
}
In AndroidManifest
<receiver android:name=".util.WifiReceiver" android:enabled="true">
<intent-filter>
<action android:name="android.net.wifi.WIFI_STATE_CHANGED" />
<action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
</intent-filter>
</receiver>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

To detect WIFI connection state, I have used CONNECTIVITY_ACTION from ConnectivityManager class so:
IntentFilter filter=new IntentFilter();
filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
registerReceiver(receiver, filter);
and from your BroadCastReceiver:
if (ConnectivityManager.CONNECTIVITY_ACTION.equals(action)) {
int networkType = intent.getIntExtra(
android.net.ConnectivityManager.EXTRA_NETWORK_TYPE, -1);
if (ConnectivityManager.TYPE_WIFI == networkType) {
NetworkInfo networkInfo = (NetworkInfo) intent
.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
if (networkInfo != null) {
if (networkInfo.isConnected()) {
// TODO: wifi is connected
} else {
// TODO: wifi is not connected
}
}
}
}
ps:works fine for me:)

This code does not require permission at all. It is restricted only to Wi-Fi network connectivity state changes (any other network is not taken into account). The receiver is statically published in the AndroidManifest.xml file and does not need to be exported as it will be invoked by the system protected broadcast, NETWORK_STATE_CHANGED_ACTION, at every network connectivity state change.
AndroidManifest:
<receiver
android:name=".WifiReceiver"
android:enabled="true"
android:exported="false">
<intent-filter>
<!--protected-broadcast: Special broadcast that only the system can send-->
<!--Corresponds to: android.net.wifi.WifiManager.NETWORK_STATE_CHANGED_ACTION-->
<action android:name="android.net.wifi.STATE_CHANGE" />
</intent-filter>
</receiver>
BroadcastReceiver class:
public class WifiReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
/*
Tested (I didn't test with the WPS "Wi-Fi Protected Setup" standard):
In API15 (ICE_CREAM_SANDWICH) this method is called when the new Wi-Fi network state is:
DISCONNECTED, OBTAINING_IPADDR, CONNECTED or SCANNING
In API19 (KITKAT) this method is called when the new Wi-Fi network state is:
DISCONNECTED (twice), OBTAINING_IPADDR, VERIFYING_POOR_LINK, CAPTIVE_PORTAL_CHECK
or CONNECTED
(Those states can be obtained as NetworkInfo.DetailedState objects by calling
the NetworkInfo object method: "networkInfo.getDetailedState()")
*/
/*
* NetworkInfo object associated with the Wi-Fi network.
* It won't be null when "android.net.wifi.STATE_CHANGE" action intent arrives.
*/
NetworkInfo networkInfo = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
if (networkInfo != null && networkInfo.isConnected()) {
// TODO: Place the work here, like retrieving the access point's SSID
/*
* WifiInfo object giving information about the access point we are connected to.
* It shouldn't be null when the new Wi-Fi network state is CONNECTED, but it got
* null sometimes when connecting to a "virtualized Wi-Fi router" in API15.
*/
WifiInfo wifiInfo = intent.getParcelableExtra(WifiManager.EXTRA_WIFI_INFO);
String ssid = wifiInfo.getSSID();
}
}
}
Permissions:
None

Android O removed the possibility to receive the implicit broadcasts for a wifi state change. So if your app is closed, you'll not be able to receive them. The new WorkManager has the ability to run when your app is closed, so I've experimented a bit with it and it seems to work quite well:
Add this to your dependencies:
implementation "android.arch.work:work-runtime:1.0.0-alpha08"
WifiConnectWorker.kt
class WifiConnectWorker : Worker() {
override fun doWork(): Result {
Log.i(TAG, "I think we connected to a wifi")
return Result.SUCCESS
}
}
MainActivity.kt
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.main_activity)
val workManager = WorkManager.getInstance()
// Add constraint to start the worker when connecting to WiFi
val request = OneTimeWorkRequest.Builder(WifiConnectWorker::class.java)
.setConstraints(Constraints.Builder()
.setRequiredNetworkType(UNMETERED)
.build())
.build()
// The worker should be started, even if your app is closed
workManager.beginUniqueWork("watch_wifi", REPLACE, request).enqueue()
}
}
Keep in mind that this was just a quick test for a one-time notification. There is more work to do to always get notified when WiFi is turned on and off.
PS: When the app is force quit, the worker is not started, it seems WorkManager is canceling the requests then.

November 2020:
I have dealt too much with items deprecated by Google. Finally I found a solution to my particular requirement using "registerNetworkCallback" as Google currently suggests.
What I needed was a simple way to detect that my device has an IPv4 assigned in WIFI.
(I haven't tried other cases, my requirement was very specific, but maybe this method, without deprecated elements, will serve as a basis for other cases).
Tested on APIs 23, 24 and 26 (physical devices) and APIs 28 and 29 (emulated devices).
ConnectivityManager cm
= (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkRequest.Builder builder = new NetworkRequest.Builder();
cm.registerNetworkCallback
(
builder.build(),
new ConnectivityManager.NetworkCallback()
{
#Override
public void onAvailable(Network network)
{
//Actions to take with Wifi available.
}
#Override
public void onLost(Network network)
{
//Actions to take with lost Wifi.
}
}
);
(Implemented inside "MainActivity.Oncreate")
Note: In manifest needs "android.permission.ACCESS_NETWORK_STATE"

Here is an example of my code, that takes into account the users preference of only allowing comms when connected to Wifi.
I am calling this code from inside an IntentService before I attempt to download stuff.
Note that NetworkInfo will be null if there is no network connection of any kind.
private boolean canConnect()
{
ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
boolean canConnect = false;
boolean wifiOnly = SharedPreferencesUtils.wifiOnly();
NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
if(networkInfo != null)
{
if(networkInfo.isConnected())
{
if((networkInfo.getType() == ConnectivityManager.TYPE_WIFI) ||
(networkInfo.getType() != ConnectivityManager.TYPE_WIFI && !wifiOnly))
{
canConnect = true;
}
}
}
return canConnect;
}

I have two methods to detect WIFI connection receiving the application context:
1)my old method
public boolean isConnectedWifi1(Context context) {
try {
ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
if (networkInfo != null) {
NetworkInfo[] netInfo = connectivityManager.getAllNetworkInfo();
for (NetworkInfo ni : netInfo) {
if ((ni.getTypeName().equalsIgnoreCase("WIFI"))
&& ni.isConnected()) {
return true;
}
}
}
return false;
} catch (Exception e) {
Log.e(TAG, e.getMessage());
}
return false;
}
2)my New method (I´m currently using this method):
public boolean isConnectedWifi(Context context) {
ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
return networkInfo.isConnected();
}

1) I tried Broadcast Receiver approach as well even though I know CONNECTIVITY_ACTION/CONNECTIVITY_CHANGE is deprecated in API 28 and not recommended. Also bound to using explicit register, it listens as long as app is running.
2) I also tried Firebase Dispatcher which works but not beyond app killed.
3) Recommended way found is WorkManager to guarantee execution beyond process killed and internally using registerNetworkRequest()
The biggest evidence in favor of #3 approach is referred by Android doc itself. Especially for apps in the background.
Also here
In Android 7.0 we're removing three commonly-used implicit broadcasts — CONNECTIVITY_ACTION, ACTION_NEW_PICTURE, and ACTION_NEW_VIDEO — since those can wake the background processes of multiple apps at once and strain memory and battery. If your app is receiving these, take advantage of the Android 7.0 to migrate to JobScheduler and related APIs instead.
So far it works fine for us using Periodic WorkManager request.
Update: I ended up writing 2 series medium post about it.

I used this code:
public class MainActivity extends Activity
{
.
.
.
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
.
.
.
}
#Override
protected void onResume()
{
super.onResume();
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION);
registerReceiver(broadcastReceiver, intentFilter);
}
#Override
protected void onPause()
{
super.onPause();
unregisterReceiver(broadcastReceiver);
}
private final BroadcastReceiver broadcastReceiver = new BroadcastReceiver()
{
#Override
public void onReceive(Context context, Intent intent)
{
final String action = intent.getAction();
if (action.equals(WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION))
{
if (intent.getBooleanExtra(WifiManager.EXTRA_SUPPLICANT_CONNECTED, false))
{
// wifi is enabled
}
else
{
// wifi is disabled
}
}
}
};
}

For all those who enjoying CONNECTIVITY_CHANGE broadcast, please note this is no more fired when app is in background in Android O.
https://developer.android.com/about/versions/o/background.html

You Can use Broadcast With Filter
<receiver
android:name=".receivers.ConnectionType"
android:enabled="true"
android:exported="true">
<intent-filter>
<action android:name="android.net.wifi.WIFI_STATE_CHANGED" />
</intent-filter>
</receiver>
after that, you can listen to the value returned like that
#Override
public void onReceive(Context context, Intent intent) {
int wifiState = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE, WifiManager.WIFI_STATE_UNKNOWN);
if(wifiState==WifiManager.WIFI_STATE_ENABLED){
Toast.makeText(context, "WIFI on", Toast.LENGTH_SHORT).show();
}else if(wifiState==WifiManager.WIFI_STATE_DISABLED) {
Toast.makeText(context, "WIFI OFF", Toast.LENGTH_SHORT).show();
}
}
it will fire every time WIFI enabled or disabled

ANDROID: if WiFi is enabled AND active, launch an intent

This is what I would like to do :
=> IF WiFi is enabled AND active, launch an intent (in fact it's a WebView that gets its content=>the instructions of my app on the web)
=> IF NOT, then I would launch another intent so that I don't show a WebView with "Web page not available ... The Web page at http://www.mywebsite.com might be temporarily down or it may have moved ..."
I tought initially to use
if(wifi.isWifiEnabled())
but that does not say if the Wifi connection is ACTIVE or not. It says only that the user has turned the switch on. The device may or may not be connected... Is this correct ?
Then I tried to use :
if (wifi.getConnectionInfo().getSSID()!= null)
but I noticed that it returns a string even if the connection has been lost or has been disabled ... ?
How should I do then ?
wifi = (WifiManager)getSystemService(Context.WIFI_SERVICE);
Intent intent_instructions;
if (wifi.getConnectionInfo().getSSID()!= null){
Log.i("Hub", "WiFi is enabled AND active !");
Log.i("Hub", "SSID = "+wifi.getConnectionInfo().getSSID());
intent_instructions = new Intent(this, Instructions.class);
}else{
Log.i("Hub", "NO WiFi");
intent_instructions = new Intent(this, Instructions_No_WiFi.class);
}
this.startActivity(intent_instructions);
Is there a more general way to test if the device has the connectivity to the internet just before launching an intent ? be it through Wifi, 3G, etc ...
Thanks in advance for your help.

You can use the following code to check for connectivity:
private static boolean isConnected(Context context) {
ConnectivityManager connectivityManager = (ConnectivityManager)
context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = null;
if (connectivityManager != null) {
networkInfo =
connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
}
return networkInfo == null ? false : networkInfo.isConnected();
}
Please make sure that you've registered the android.net.conn.CONNECTIVITY_CHANGE intent in your Manifest, or else, you'll never receive a notification that you're online.
I've been struggling with this issue for the last couple of days and I just now realized that I needed to register CONNECTIVITY_CHANGE and not only WIFI_STATE_CHANGED.

Try android.net.ConnectivityManager.getActiveNetworkInfo(): if it returns null you have no connection; if it returns a NetworkInfo object, you can check the connection's state with NetworkInfo.getState(), and if it's NetworkInfo.State.CONNECTED then you're connected, else you're not.

You can do it as follows:
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if(WifiManager.WIFI_STATE_CHANGED_ACTION.equals(action)){
Log.d("WIFI", "WIFI has changed");
int wifiState = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE, -1);
Log.d("WIFI", "WIFI State = " + wifiState);
setCurrentWifiState(wifiState);
}
You will get 0,1,2,3 depending on which state the Wifi is in, so for example 2 is connecting, you can check the rest in the documents

In your BroadcastReceiver class:
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION)){
boolean connected = intent.getBooleanExtra(WifiManager.EXTRA_SUPPLICANT_CONNECTED, false);
if (connected){
// start your service here
}
}
}
And in your AndroidManifest.xml make sure you register for the android.net.wifi.supplicant.CONNECTION_CHANGE broadcast intent.
<intent-filter >
<action android:name="android.net.wifi.supplicant.CONNECTION_CHANGE" />
</intent-filter>

isConnected() doesnt work fully ok, research something else
final ConnectivityManager connMgr = (ConnectivityManager)
this.getSystemService(Context.CONNECTIVITY_SERVICE);
final android.net.NetworkInfo wifi =
connMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
final android.net.NetworkInfo mobile =
connMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
if( wifi.isAvailable() && wifi.getDetailedState() == DetailedState.CONNECTED){
Toast.makeText(this, "Wifi" , Toast.LENGTH_LONG).show();
}
else if( mobile.isAvailable() && mobile.getDetailedState() == DetailedState.CONNECTED ){
Toast.makeText(this, "Mobile 3G " , Toast.LENGTH_LONG).show();
}
else
{
Toast.makeText(this, "No Network " , Toast.LENGTH_LONG).show();
}
this code check if you are with wifi or 3g or nothing , in the case of wifi on but not connected to a net or 3g have signal problem it detect this details, with DetailedStates