now only i commit actionlistener

src/ChatArea.java

+import javax.swing.*;
+import java.awt.*;
+
+public class ChatArea extends JTextArea {
+    public ChatArea(){
+        super(10 , 30);
+        setVisible(true);
+    }
+    public void addMessage(String userName , String Message){
+        this.append(userName + " : " + Message + "\n");
+    }
+}

src/ChatRoomGUI.java

+import javax.swing.*;
+import javax.swing.border.EtchedBorder;
+import java.awt.*;
+
+public class ChatRoomGUI extends JFrame {
+    private final String WINDOWS_TITLE = "AUT Chat Room";
+    private final int WIDTH = 500, HEIGHT = 500;
+    private final int X = 100, Y = 100;
+    private ChatArea chatBox = new ChatArea();
+    private JPanel users = new JPanel();
+    private ParticipantArea user = new ParticipantArea();
+    private MessageArea messageArea = new MessageArea();
+    private JPanel msgArea = new JPanel();
+    public ChatRoomGUI(){
+        super();
+        this.setTitle(WINDOWS_TITLE);
+        this.setSize(WIDTH, HEIGHT);
+        this.add(new JScrollPane().add(chatBox) ,BorderLayout.CENTER );
+        chatBox.setBorder(BorderFactory.createEtchedBorder(EtchedBorder.RAISED));
+        users.setLayout(new GridLayout(2,1));
+        users.add(user.getLabel());
+        users.add(user.getList());
+        this.add(users , BorderLayout.WEST);
+        msgArea.setLayout(new GridLayout(1,2));
+        msgArea.add(new JScrollPane().add(messageArea));
+        msgArea.add(messageArea.getBtn());
+        this.add(msgArea , BorderLayout.PAGE_END);
+        users.setVisible(true);
+        this.setLocation(X, Y);
+        this.setVisible(true);
+        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+    }
+
+    public MessageArea getMessageArea() {
+        return messageArea;
+    }
+
+    public void addNewMessage(String name , String message){
+        chatBox.addMessage(name , message);
+    }
+    public void addNewUser(String name){
+        user.addUser(name);
+    }
+}

src/Logic.java

+import network.Network;
+
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import java.io.IOException;
+
+public class Logic implements ActionListener {
+    private static UsernameFrame usernamebox;
+    public void actionPerformed(ActionEvent e) {
+        String user = usernamebox.textField.getText();
+        usernamebox.setVisible(false);
+        ChatRoomGUI chatRoom = new ChatRoomGUI();
+        chatRoom.addNewUser(user);
+        ActionListener listener = new ActionListener() {
+            public void actionPerformed(ActionEvent e) {
+                String text = chatRoom.getMessageArea().getText();
+                Network network = new Network();
+                network.send(text);
+                try {
+                    chatRoom.addNewMessage(user , network.receive());
+                } catch (IOException e1) {
+                    e1.printStackTrace();
+                }
+                chatRoom.getMessageArea().setText("");
+            }
+        };
+        chatRoom.getMessageArea().addActionListener(listener);
+        chatRoom.getMessageArea().getBtn().addActionListener(listener);
+    }
+    public static void main(String[] args) {
+
+        Logic.usernamebox = new UsernameFrame();
+    }
+}

src/MessageArea.java

+import javax.swing.*;
+
+public class MessageArea extends JTextField {
+    private JButton btn;
+    public MessageArea(){
+        super();
+        btn = new JButton("Send");
+        this.setEditable(true);
+        this.setVisible(true);
+    }
+
+    public JButton getBtn() {
+        return btn;
+    }
+
+}

src/ParticipantArea.java

+import javax.swing.*;
+
+public class ParticipantArea extends JList {
+    private JLabel label;
+    private DefaultListModel<String> listOfUsers = new DefaultListModel<>();
+    private JList<String> list = new JList<>(listOfUsers);
+    public ParticipantArea(){
+        label = new JLabel("Online User");
+        this.setVisible(true);
+    }
+
+    public JLabel getLabel() {
+        return label;
+    }
+
+    public JList<String> getList() {
+        return list;
+    }
+
+    public void addUser(String name){
+        listOfUsers.addElement(name);
+    }
+
+    public DefaultListModel<String> getListOfUsers() {
+        return listOfUsers;
+    }
+}

src/UsernameFrame.java

+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+
+public class UsernameFrame extends JFrame {
+    private static final int WIDTH = 300, HEIGHT = 100;
+    JTextField textField;
+    JButton btn;
+    public UsernameFrame(){
+        super();
+        this.setLayout(new BorderLayout());
+        JLabel label = new JLabel("Pick a Name");
+        add(label , BorderLayout.PAGE_START);
+        textField = new JTextField();
+        add(textField , BorderLayout.CENTER);
+        btn = new JButton("Na be intellij");
+        add(btn , BorderLayout.PAGE_END);
+        setSize(WIDTH , HEIGHT);
+        setVisible(true);
+        Logic logic = new Logic();
+        btn.addActionListener(logic);
+        textField.addActionListener(logic);
+        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
+
+    }
+
+}