Main.java

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;

class ParallelPrinter {
    final BlockingQueue<String> messageQueue;

    public ParallelPrinter(BlockingQueue<String> messageQueue) {
        this.messageQueue = messageQueue;
    }

    public void poll() {
        Thread running = new Thread(new Runnable() {
            @Override
            public void run() {
                while (true) {
                    try {
                        String data = messageQueue.take();
                        System.out.println(data);
                    } catch (InterruptedException e) {
                        System.err.println("Error occurred:" + e);
                    }
                }
            }
        });
        running.start();
    }
}

class SubscriberGui extends JFrame
{
    final BlockingQueue<String> messageQueue;

    private String subscribe = "";
    private String answer;

    public SubscriberGui(BlockingQueue<String> messageQueue)
    {
        super("Frame");
        this.messageQueue = messageQueue;
        initGui();
    }

    private void initGui()
    {
        setSize(400, 400);
        setLayout(new BorderLayout());

        final JButton sendSubcrButton = new JButton("Send");

        final JTextField subscrLine = new JTextField(50);

        JLabel label = new JLabel("Enter your data here:");
        JPanel inputPanel = new JPanel();
        inputPanel.add(label);
        inputPanel.add(subscrLine);

        add(inputPanel, BorderLayout.PAGE_START);
        add(sendSubcrButton, BorderLayout.PAGE_END);

        pack();
        setResizable(false);

        sendSubcrButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                if (e.getSource() == sendSubcrButton)
                {
                    subscribe = subscrLine.getText();
                    messageQueue.offer(subscribe);
                }
            }
        });

        setLocationRelativeTo(null);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    }
}

public class Main {
    public static void main(String[] args) throws InterruptedException {
        final BlockingQueue<String> queue = new LinkedBlockingQueue<String>();
        ParallelPrinter parallelPrinter = new ParallelPrinter(queue);
        parallelPrinter.poll();
        /** Gui in edt **/
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                SubscriberGui sgui = new SubscriberGui(queue);
                sgui.setVisible(true);
            }
        });
        System.out.println("stop"); //тут печатать
    }
}