Isso verifica apenas se a interface de rede está disponível, não garante que um serviço de rede específico esteja disponível, por exemplo, pode haver baixo sinal ou tempo de inatividade do servidor
private boolean isNetworkInterfaceAvailable(Context context) {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
return activeNetwork != null && activeNetwork.isConnectedOrConnecting();
}
se você deseja fazer uma conexão real para garantir que sua conexão possa coletar dados de um servidor ou de qualquer URL:
private boolean isAbleToConnect(String url, int timeout) {
try {
URL myUrl = new URL(url);
URLConnection connection = myUrl.openConnection();
connection.setConnectTimeout(timeout);
connection.connect();
return true;
} catch (Exception e) {
Log.i("exception", "" + e.getMessage());
return false;
}
}
Essa função precisa ser agrupada em um thread de segundo plano:
final String action = intent.getAction();
if (intent.getAction().equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
checkConnectivity(context);
}
}
private void checkConnectivity(final Context context) {
if (!isNetworkInterfaceAvailable(context)) {
Toast.makeText(context, "You are OFFLINE!", Toast.LENGTH_SHORT).show();
return;
}
final Handler handler = new Handler();
new Thread(new Runnable() {
@Override
public void run() {
final boolean isConnected = isAbleToConnect("http://www.google.com", 1000);
handler.post(new Runnable() {
@Override
public void run() {
if (isConnected)
Toast.makeText(context, "You are ONLINE!", Toast.LENGTH_SHORT).show();
else
Toast.makeText(context, "You are OFFLINE!", Toast.LENGTH_SHORT).show();
}
});
}
}).start();
}
Adicione as permissões necessárias:
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET"/>
Adicione esta linha em aplicativo no arquivo de manifesto:
android:usesCleartextTraffic="true"
Adicione o receptor ao arquivo de manifesto:
<receiver android:name=".ConnectivityChangeReceiver" >
<intent-filter>
<action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
</intent-filter>
</receiver>
Registrar / cancelar o registro do BR em sua atividade:
@Override
protected void onStart() {
super.onStart();
IntentFilter filter = new IntentFilter("android.net.conn.CONNECTIVITY_CHANGE");
registerReceiver(connectivityChangeReceiver, filter);
}
@Override
protected void onDestroy() {
super.onDestroy();
unregisterReceiver(connectivityChangeReceiver);
}
esta é toda a classe de transmissão:
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Handler;
import android.util.Log;
import android.widget.Toast;
import java.net.URL;
import java.net.URLConnection;
public class ConnectivityChangeReceiver extends BroadcastReceiver {
@Override
public void onReceive(final Context context, final Intent intent) {
final String action = intent.getAction();
if (intent.getAction().equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
checkConnectivity(context);
}
}
private void checkConnectivity(final Context context) {
if (!isNetworkInterfaceAvailable(context)) {
Toast.makeText(context, "You are OFFLINE!", Toast.LENGTH_SHORT).show();
return;
}
final Handler handler = new Handler();
new Thread(new Runnable() {
@Override
public void run() {
final boolean isConnected = isAbleToConnect("http://www.google.com", 1000);
handler.post(new Runnable() {
@Override
public void run() {
if (isConnected)
Toast.makeText(context, "You are ONLINE!", Toast.LENGTH_SHORT).show();
else
Toast.makeText(context, "You are OFFLINE!", Toast.LENGTH_SHORT).show();
}
});
}
}).start();
}
//This only checks if the network interface is available, doesn't guarantee a particular network service is available, for example, there could be low signal or server downtime
private boolean isNetworkInterfaceAvailable(Context context) {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
return activeNetwork != null && activeNetwork.isConnectedOrConnecting();
}
//This makes a real connection to an url and checks if you can connect to this url, this needs to be wrapped in a background thread
private boolean isAbleToConnect(String url, int timeout) {
try {
URL myUrl = new URL(url);
URLConnection connection = myUrl.openConnection();
connection.setConnectTimeout(timeout);
connection.connect();
return true;
} catch (Exception e) {
Log.i("exception", "" + e.getMessage());
return false;
}
}
}