import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class pruebaText {

    private JFrame frame;
    private JLabel lblText;
    int cont = 0;
    private JLabel lblText5;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    pruebaText window = new pruebaText();
                    window.frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the application.
     */
    public pruebaText() {
        initialize();

    }

    /**
     * Initialize the contents of the frame.
     */
    private void initialize() {
        frame = new JFrame();
        frame.setBounds(100, 100, 450, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(null);

        lblText = new JLabel("");
        lblText.setBounds(89, 66, 46, 14);
        frame.getContentPane().add(lblText);

        JButton btnNewButton = new JButton("New button");
        btnNewButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                try{
                    while (cont<10) {
                        Thread.sleep(1000);
                        cont++;
                        System.out.println(cont);
                        if (cont==5) {
                            lblText.setText("hola");
                        }
                    }

                }catch (Exception e1) {
                    // TODO: handle exception
                    System.out.println(e1);
                }
            }

        });
        btnNewButton.setBounds(89, 197, 89, 23);
        frame.getContentPane().add(btnNewButton);

        lblText5 = new JLabel("");
        lblText5.setBounds(341, 38, 46, 14);
        frame.getContentPane().add(lblText5);
    }
}

public static void mostarTexto() {
    for (int i = 0; i < 10; i++) {
        try {
            Thread.sleep(1000);
             //Para ver la evulocion de i en Console de eclipe
            System.out.println(i);

            if (i / 2 == 0) {
                lblTexto.setText("hola");
            } else {
                lblTexto.setText(" ");
            }
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

}