C'è un aggiornamento a questa risposta a partire da marzo 2020 che supporta API.15 tramite API.29, puoi trovarlo seguendo la risposta originale
Risposta febbraio 2019
Per verificare se sei online:
boolean isOnline() {
// Checking internet connectivity
ConnectivityManager connectivityMgr = (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = null;
if (connectivityMgr != null) {
activeNetwork = connectivityMgr.getActiveNetworkInfo();
}
return activeNetwork != null;
}
Per ottenere il tipo di connettività Internet prima / dopo Android M
void internetType() {
// Checking internet connectivity
ConnectivityManager connectivityMgr = (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = null;
if (connectivityMgr != null) {
activeNetwork = connectivityMgr.getActiveNetworkInfo();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
NetworkCapabilities nc = connectivityMgr.getNetworkCapabilities(connectivityMgr.getActiveNetwork());
if (nc.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)) {
// connected to mobile data
} else if (nc.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)) {
// connected to wifi
}
} else {
if (activeNetwork.getType() == ConnectivityManager.TYPE_WIFI) {
// connected to wifi
} else if (activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE) {
// connected to mobile data
}
}
}
}
Tutti i casi richiedono un'autorizzazione per accedere allo stato della rete
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
Aggiornamento marzo 2020
Come NetworkInfo
è deprecato e a partire da API 29 da ora dobbiamo usare ConnectivityManager.NetworkCallback
con il suo cambio di stato della rete onAvailable()
e onLost()
callback.
Uso:
- È possibile utilizzare questa libreria o utilizzare direttamente la seguente classe di utilità che fa parte di questa libreria.
Caratteristiche
- È consapevole del ciclo di vita implementando
LifecycleObserver
per evitare perdite di memoria eseguendo una pulizia del onDestroy()
metodo.
- Supporta da API 15 (Ice Cream Sandwich) a API 29 (Android Q)
- Per le API precedenti all'API 21, utilizza un contesto
BoradcastReceiver
e NetworkInfo
, e utilizza ConnectivityManager.NetworkCallback
per l'API 21 e successive.
- Quando entrambe le reti WiFi e cellulare sono attive, l'ascoltatore di connettività non si interromperà quando il WiFi viene disconnesso durante la transizione alla rete cellulare.
- Quando la rete cellulare è attiva, l'ascoltatore di connettività non si interromperà quando il WiFi è connesso e essendo la rete attiva (poiché questa è la rete preferita).
- Se hai intenzione di utilizzare la libreria, non è necessario includere questa autorizzazione
android.permission.ACCESS_NETWORK_STATE
; ma devi includerlo se intendi utilizzare la classe di utilità.
funzionalità
- Ottieni lo stato di connettività corrente (online / offline).
- Controllo / ascolto continuo della connessione Internet e attivazione di una richiamata quando il dispositivo passa offline o online.
- Ottieni il tipo di connessione Internet attiva (WiFi o cellulare).
- Ottieni il tipo di tutte le reti disponibili (WiFi o cellulare). >> Supportato solo su API 21+
- Ottieni il numero di tutte le reti disponibili >> Supportato solo su API 21+
@RequiresApi(api = Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1)
public class ConnectionUtil implements LifecycleObserver {
private static final String TAG = "LOG_TAG";
private ConnectivityManager mConnectivityMgr;
private Context mContext;
private NetworkStateReceiver mNetworkStateReceiver;
/*
* boolean indicates if my device is connected to the internet or not
* */
private boolean mIsConnected = false;
private ConnectionMonitor mConnectionMonitor;
/**
* Indicates there is no available network.
*/
private static final int NO_NETWORK_AVAILABLE = -1;
/**
* Indicates this network uses a Cellular transport.
*/
public static final int TRANSPORT_CELLULAR = 0;
/**
* Indicates this network uses a Wi-Fi transport.
*/
public static final int TRANSPORT_WIFI = 1;
public interface ConnectionStateListener {
void onAvailable(boolean isAvailable);
}
public ConnectionUtil(Context context) {
mContext = context;
mConnectivityMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
((AppCompatActivity) mContext).getLifecycle().addObserver(this);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
mConnectionMonitor = new ConnectionMonitor();
NetworkRequest networkRequest = new NetworkRequest.Builder()
.addTransportType(NetworkCapabilities.TRANSPORT_CELLULAR)
.addTransportType(NetworkCapabilities.TRANSPORT_WIFI)
.build();
mConnectivityMgr.registerNetworkCallback(networkRequest, mConnectionMonitor);
}
}
/**
* Returns true if connected to the internet, and false otherwise
*
* <p>
* NetworkInfo is deprecated in API 29
* https://developer.android.com/reference/android/net/NetworkInfo
* <p>
* getActiveNetworkInfo() is deprecated in API 29
* https://developer.android.com/reference/android/net/ConnectivityManager#getActiveNetworkInfo()
* <p>
* getNetworkInfo(int) is deprecated as of API 23
* https://developer.android.com/reference/android/net/ConnectivityManager#getNetworkInfo(int)
*/
public boolean isOnline() {
mIsConnected = false;
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P) {
// Checking internet connectivity
NetworkInfo activeNetwork = null;
if (mConnectivityMgr != null) {
activeNetwork = mConnectivityMgr.getActiveNetworkInfo(); // Deprecated in API 29
}
mIsConnected = activeNetwork != null;
} else {
Network[] allNetworks = mConnectivityMgr.getAllNetworks(); // added in API 21 (Lollipop)
for (Network network : allNetworks) {
NetworkCapabilities networkCapabilities = mConnectivityMgr.getNetworkCapabilities(network);
if (networkCapabilities != null) {
if (networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)
|| networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)
|| networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET))
mIsConnected = true;
}
}
}
return mIsConnected;
}
/**
* Returns
* <p> <p>
* <p><p> NO_NETWORK_AVAILABLE >>> when you're offline
* <p><p> TRANSPORT_CELLULAR >> When Cellular is the active network
* <p><p> TRANSPORT_WIFI >> When Wi-Fi is the Active network
* <p>
*/
public int getActiveNetwork() {
NetworkInfo activeNetwork = mConnectivityMgr.getActiveNetworkInfo(); // Deprecated in API 29
if (activeNetwork != null)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
NetworkCapabilities capabilities = mConnectivityMgr.getNetworkCapabilities(mConnectivityMgr.getActiveNetwork());
if (capabilities != null)
if (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)) {
// connected to mobile data
return TRANSPORT_CELLULAR;
} else if (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)) {
// connected to wifi
return TRANSPORT_WIFI;
}
} else {
if (activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE) { // Deprecated in API 28
// connected to mobile data
return TRANSPORT_CELLULAR;
} else if (activeNetwork.getType() == ConnectivityManager.TYPE_WIFI) { // Deprecated in API 28
// connected to wifi
return TRANSPORT_WIFI;
}
}
return NO_NETWORK_AVAILABLE;
}
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
public int getAvailableNetworksCount() {
int count = 0;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
Network[] allNetworks = mConnectivityMgr.getAllNetworks(); // added in API 21 (Lollipop)
for (Network network : allNetworks) {
NetworkCapabilities networkCapabilities = mConnectivityMgr.getNetworkCapabilities(network);
if (networkCapabilities != null)
if (networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)
|| networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR))
count++;
}
}
return count;
}
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
public List<Integer> getAvailableNetworks() {
List<Integer> activeNetworks = new ArrayList<>();
Network[] allNetworks; // added in API 21 (Lollipop)
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
allNetworks = mConnectivityMgr.getAllNetworks();
for (Network network : allNetworks) {
NetworkCapabilities networkCapabilities = mConnectivityMgr.getNetworkCapabilities(network);
if (networkCapabilities != null) {
if (networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI))
activeNetworks.add(TRANSPORT_WIFI);
if (networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR))
activeNetworks.add(TRANSPORT_CELLULAR);
}
}
}
return activeNetworks;
}
public void onInternetStateListener(ConnectionStateListener listener) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
mNetworkStateReceiver = new NetworkStateReceiver(listener);
IntentFilter intentFilter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
mContext.registerReceiver(mNetworkStateReceiver, intentFilter);
} else {
mConnectionMonitor.setOnConnectionStateListener(listener);
}
}
@OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
public void onDestroy() {
Log.d(TAG, "onDestroy");
((AppCompatActivity) mContext).getLifecycle().removeObserver(this);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
if (mConnectionMonitor != null)
mConnectivityMgr.unregisterNetworkCallback(mConnectionMonitor);
} else {
if (mNetworkStateReceiver != null)
mContext.unregisterReceiver(mNetworkStateReceiver);
}
}
public class NetworkStateReceiver extends BroadcastReceiver {
ConnectionStateListener mListener;
public NetworkStateReceiver(ConnectionStateListener listener) {
mListener = listener;
}
@Override
public void onReceive(Context context, Intent intent) {
if (intent.getExtras() != null) {
NetworkInfo activeNetworkInfo = mConnectivityMgr.getActiveNetworkInfo(); // deprecated in API 29
/*
* activeNetworkInfo.getState() deprecated in API 28
* NetworkInfo.State.CONNECTED deprecated in API 29
* */
if (!mIsConnected && activeNetworkInfo != null && activeNetworkInfo.getState() == NetworkInfo.State.CONNECTED) {
Log.d(TAG, "onReceive: " + "Connected To: " + activeNetworkInfo.getTypeName());
mIsConnected = true;
mListener.onAvailable(true);
} else if (intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, Boolean.FALSE)) {
if (!isOnline()) {
mListener.onAvailable(false);
mIsConnected = false;
}
}
}
}
}
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
public class ConnectionMonitor extends ConnectivityManager.NetworkCallback {
private ConnectionStateListener mConnectionStateListener;
void setOnConnectionStateListener(ConnectionStateListener connectionStateListener) {
mConnectionStateListener = connectionStateListener;
}
@Override
public void onAvailable(@NonNull Network network) {
if (mIsConnected)
return;
Log.d(TAG, "onAvailable: ");
if (mConnectionStateListener != null) {
mConnectionStateListener.onAvailable(true);
mIsConnected = true;
}
}
@Override
public void onLost(@NonNull Network network) {
if (getAvailableNetworksCount() == 0) {
mConnectionStateListener.onAvailable(false);
mIsConnected = false;
}
}
}
}