import java.awt.Color;
import java.awt.Dimension;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.SwingConstants;

public class Libre extends JPanel {
  public Libre() {
    JButton bouton = new JButton("bouton");
    JScrollPane ecriture = new JScrollPane(new JTextArea());
    JLabel message =new JLabel("Bonjour", SwingConstants.CENTER);

    setLayout(null);
    setPreferredSize(new Dimension(200, 200)); 
    bouton.setBounds(30, 10, 150, 30);
    message.setBackground(Color.YELLOW);
    message.setOpaque(true);
    ecriture.setSize(100, 100);
    ecriture.setLocation(60, 50);
    message.setBounds(10, 170, 100, 20);
    add(bouton);
    add(ecriture);
    add(message);
  } 
}

class EssaiLibre {  
  public static void main(String[] arg) {
      JFrame monCadre = new JFrame();

      monCadre.setContentPane(new Libre()); 
      monCadre.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      monCadre.pack();
      monCadre.setVisible(true); 
    }
}