Refactor: make PORT a global constant

src/main/java/ChatClient.java

@@ -7,7 +7,6 @@ import java.net.Socket;
 
 public class ChatClient extends JFrame implements KeyListener {
     private String address;
-    private int port;
     private Socket connectionToServer;
     private BufferedReader fromServerReader;
     private PrintWriter toServerWriter;
@@ -17,9 +16,8 @@ public class ChatClient extends JFrame implements KeyListener {
     private JTextField inputTextField;
     private JScrollPane outputScrollPane;
 
-    public ChatClient(int port) {
+    public ChatClient() {
         super("Chat");
-        this.port = port;
         address = JOptionPane.showInputDialog("bitte IP-Adresse");
         
         if (address != null) {
@@ -48,7 +46,7 @@ public class ChatClient extends JFrame implements KeyListener {
     }
     private void receiveMessages() {
         try {
-            connectionToServer = new Socket(address, port);
+            connectionToServer = new Socket(address, Constants.PORT);
             fromServerReader = new BufferedReader(new InputStreamReader(connectionToServer.getInputStream()));
             toServerWriter = new PrintWriter(new OutputStreamWriter(connectionToServer.getOutputStream()));
 
@@ -108,6 +106,6 @@ public class ChatClient extends JFrame implements KeyListener {
     }
 
     public static void main(String[] args) {
-        new ChatClient(3141);
+        new ChatClient();
     }
 }

src/main/java/Constants.java

@@ -1,4 +1,5 @@
 public class Constants {
     public static final int WINDOW_WIDTH  = 800;
     public static final int WINDOW_HEIGHT = 600;
+    public static final int PORT          = 3141;
 }