Java GUI

import javax.swing.*;
import java.awt.event.*;

public class test {
	public static void main(String args[]){
		MainFrame m = new MainFrame();
		m.setVisible(true);
		try {
			m.leabl1.setText("TEST 1");
			Thread.currentThread().sleep(5000);
			m.leabl1.setText("TEST 2");
			Thread.currentThread().sleep(5000);
			m.leabl1.setText("TEST 3");
			Thread.currentThread().sleep(5000);
			m.leabl1.setText("TEST 4");
		} catch (InterruptedException e2) {
			e2.printStackTrace();
		}
	}
}

class MainFrame extends JFrame implements WindowListener{
	public JLabel leabl1 = new JLabel("TEST", JLabel.CENTER);
	
	public MainFrame(){
		this.setSize(300,200);
		this.addWindowListener(this);
		JPanel p = new JPanel();
		this.setContentPane(p);
		p.setLayout(null);
		leabl1.setBounds(0,20,300,20);
		p.add(leabl1);
	}
	
	public void windowClosing(WindowEvent e){System.exit(0);}
	public void windowOpened(WindowEvent e){}
	public void windowClosed(WindowEvent e){}
	public void windowIconified(WindowEvent e){}
	public void windowDeiconified(WindowEvent e){}
	public void windowActivated(WindowEvent e){}
	public void windowDeactivated(WindowEvent e){}
}

public void windowClosing(WindowEvent e){System.exit(0);}
	public void windowOpened(WindowEvent e){}
	public void windowClosed(WindowEvent e){}
	public void windowIconified(WindowEvent e){}
	public void windowDeiconified(WindowEvent e){}
	public void windowActivated(WindowEvent e){}
	public void windowDeactivated(WindowEvent e){}
	public void actionPerformed(ActionEvent e){
		try {
			leabl1.setText("TEST 1");
			Thread.currentThread().sleep(5000);
			leabl1.setText("TEST 2");
			Thread.currentThread().sleep(5000);
			leabl1.setText("TEST 3");
			Thread.currentThread().sleep(5000);
			leabl1.setText("TEST 4");
		} catch (InterruptedException e2) {
			e2.printStackTrace();
		}
	}

import javax.swing.*;
import java.awt.event.*;
import java.util.*;


class MainFrame extends JFrame {
    private JLabel label1 = new JLabel("TEST", JLabel.CENTER);
    private JButton launchInSwingThread = new JButton("Same thread rename");
    private JButton launchInOtherThread = new JButton("Other thread rename");


    public static void main(String args[]) {
        printCurrentThread("Main");
        MainFrame m = new MainFrame();

        m.renameLabelFewTimes();
    }

    public MainFrame(){
        JPanel p = new JPanel();
        setContentPane(p);
        p.setLayout(null);
        
        
        label1.setBounds(0, 20, 300, 20);
        launchInSwingThread.setBounds(50, 60, 200, 20);
        launchInOtherThread.setBounds(50, 90, 200, 20);
        
        p.add(label1);
        p.add(launchInSwingThread);
        p.add(launchInOtherThread);

        addActionListeners();
        

        setSize(300,200);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setVisible(true);
    }

    private void addActionListeners() {
        launchInSwingThread.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                renameLabelFewTimes();
            }
        });

        launchInOtherThread.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        renameLabelFewTimes();
                    }
                }).start();
            }
        });
    }

    private void renameLabelFewTimes() {
        printCurrentThread("Renaming");
        List<String> messages = Arrays.asList(
                "TEST 1", "TEST 2", "TEST 3", "TEST 4");

        setEnabledButtons(false);

        for (final String s: messages) {
            renameLabelAndSleep(s);
        }

        setEnabledButtons(true);
    }

    private void renameLabelAndSleep(String name) {
        System.out.println("New name: " + name);
        label1.setText(name);
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e2) {
            e2.printStackTrace();
        }
    }

    private void setEnabledButtons(boolean isEnabled) {
        launchInOtherThread.setEnabled(isEnabled);
        launchInSwingThread.setEnabled(isEnabled);
    }

    private static void printCurrentThread(String prefix) {
        System.out.println(
                prefix + " thread"+ " is " + Thread.currentThread());
    }
}