Show an error if the remote isn't reachable

When connecting as a client, only the log would display that the server wasn't reachable. Now there's a requester.

ui/src/main/java/io/xeres/ui/PrimaryStageInitializer.java

@@ -25,13 +25,15 @@
 import io.xeres.ui.client.message.ChatFrameHandler;
 import io.xeres.ui.client.message.MessageClient;
 import io.xeres.ui.controller.chat.ChatViewController;
+import io.xeres.ui.support.util.UiUtils;
 import io.xeres.ui.support.window.WindowManager;
 import javafx.application.Platform;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.context.event.EventListener;
 import org.springframework.http.HttpStatus;
 import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.client.WebClientRequestException;
 import org.springframework.web.reactive.function.client.WebClientResponseException;
 import reactor.core.publisher.Hooks;
 
@@ -74,6 +76,7 @@ public void onApplicationEvent(StageReadyEvent event)
 						windowManager.openAccountCreation(event.getStage());
 					}
 				})
+				.doOnError(WebClientRequestException.class, e -> UiUtils.showAlertError(e, Platform::exit))
 				.subscribe();
 	}
 

ui/src/main/java/io/xeres/ui/support/util/UiUtils.java

@@ -79,6 +79,11 @@ private UiUtils()
 	 * @param t the throwable
 	 */
 	public static void showAlertError(Throwable t)
+	{
+		showAlertError(t, null);
+	}
+
+	public static void showAlertError(Throwable t, Runnable action)
 	{
 		Platform.runLater(() -> {
 			if (t instanceof WebClientResponseException e)
@@ -109,6 +114,10 @@ public static void showAlertError(Throwable t)
 			{
 				alert(ERROR, "Error", t.getMessage(), ExceptionUtils.getStackTrace(t));
 			}
+			if (action != null)
+			{
+				action.run();
+			}
 			log.error("Error: {}", t.getMessage(), t);
 		});
 	}