Add scrollbar to window

src/main/java/ChatClient.java

@@ -15,6 +15,7 @@ public class ChatClient extends JFrame implements KeyListener {
     // GUI
     private JTextArea outputTextArea;
     private JTextField inputTextField;
+    private JScrollPane outputScrollPane;
 
     public ChatClient(int port) {
         super("Chat");
@@ -31,11 +32,13 @@ public class ChatClient extends JFrame implements KeyListener {
         outputTextArea.setEditable(false);
         outputTextArea.setBorder(BorderFactory.createTitledBorder("Chat"));
 
+        outputScrollPane = new JScrollPane(outputTextArea);
+
         inputTextField = new JTextField();
         inputTextField.setBorder(BorderFactory.createTitledBorder("Nachricht eingeben"));
         inputTextField.addKeyListener(this);
 
-        add(outputTextArea, BorderLayout.CENTER);
+        add(outputScrollPane, BorderLayout.CENTER);
         add(inputTextField, BorderLayout.SOUTH);
 
         setVisible(true);