Add timeout to prevent spending forever trying to determine an Internet connection

forge-core/src/main/java/forge/util/ThreadUtil.java

@@ -45,4 +45,21 @@ public class ThreadUtil {
     public static boolean isGameThread() {
         return Thread.currentThread().getName().startsWith("Game");
     }
+
+    public static <T> T executeWithTimeout(Callable<T> task, int milliseconds) {
+        ExecutorService executor = Executors.newCachedThreadPool();
+        Future<T> future = executor.submit(task);
+        T result;
+        try {
+            result = future.get(milliseconds, TimeUnit.MILLISECONDS); 
+        }
+        catch (Exception e) { //handle timeout and other exceptions
+            e.printStackTrace();
+            result = null;
+        }
+        finally {
+           future.cancel(true);
+        }
+        return result;
+    }
 }

forge-gui-android/src/forge/app/Main.java

@@ -1,6 +1,8 @@
 package forge.app;
 
 import java.io.File;
+import java.util.concurrent.Callable;
+
 import android.content.ClipData;
 import android.content.ClipboardManager;
 import android.content.Context;
@@ -20,6 +22,7 @@ import com.badlogic.gdx.backends.android.AndroidApplication;
 import forge.Forge;
 import forge.interfaces.IDeviceAdapter;
 import forge.util.FileUtil;
+import forge.util.ThreadUtil;
 
 public class Main extends AndroidApplication {
     @Override
@@ -89,15 +92,25 @@ public class Main extends AndroidApplication {
 
         @Override
         public boolean isConnectedToInternet() {
+            return Boolean.TRUE.equals(ThreadUtil.executeWithTimeout(new Callable<Boolean>() {
+                @Override
+                public Boolean call() throws Exception {
                     NetworkInfo activeNetworkInfo = connManager.getActiveNetworkInfo();
                     return activeNetworkInfo != null && activeNetworkInfo.isConnected();
                 }
+            }, 2000)); //if can't determine Internet connection within two seconds, assume not connected
+        }
 
         @Override
         public boolean isConnectedToWifi() {
+            return Boolean.TRUE.equals(ThreadUtil.executeWithTimeout(new Callable<Boolean>() {
+                @Override
+                public Boolean call() throws Exception {
                     NetworkInfo wifi = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
                     return wifi.isConnected();
                 }
+            }, 2000)); //if can't determine Internet connection within two seconds, assume not connected
+        }
 
         @Override
         public String getDownloadsDir() {