add GUI window for chat

src/main/java/ChatClient.java

@@ -2,12 +2,13 @@ import javax.swing.*;
 import java.io.IOException;
 import java.net.Socket;
 
-public class ChatClient {
+public class ChatClient extends JFrame {
     private String address;
     private int port;
     private Socket connectionToServer;
-    
+
     public ChatClient(int port) {
+        super("Chat");
         this.port = port;
         address = JOptionPane.showInputDialog("bitte IP-Adresse");
         
@@ -16,10 +17,18 @@ public class ChatClient {
         }
     }
 
+    private void initGui() {
+        setVisible(true);
+        setSize(800, 600);
+        setDefaultCloseOperation(EXIT_ON_CLOSE);
+    }
     private void receiveMessages() {
         try {
-            connectionToServer = new Socket(address, port);
-        } catch (IOException e) {
+            // Um GUI zu testen
+            // Kommentar in der Zeile 28 wird weggenohmen, wenn der Server erstellt wird.
+            // connectionToServer = new Socket(address, port);
+            initGui();
+        } catch (Exception e) {
             JOptionPane.showMessageDialog(null, "Verbindung zum Server \"" + address + "\" fehlgeschlagen.");
         }
     }