I made a Java GUI with a JTabbedPane. At the top i got three tabs. Each tabs fills the space with an seperate class, extensions of JPanel.
This is the code of the mainfile:
package gui;
import java.util.*;
import java.io.IOException;
import java.lang.*;
import java.awt.*;

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

import data.*;

public class KGUI extends JFrame implements Observer{

	private JTabbedPane tabbedPane;
	private JComponent pp, kp, okp;
	private Vereniging v;
	public KGUI (Vereniging vereniging) {
		super("Kringindeling Generator");
		this.v = vereniging;

	public void init() {   
		setLayout(new BorderLayout()); // verander naar FlowLayout
		setVisible(true);// laat het Frame zien
		addWindowListener(new WindowAdapter() {
			@Override	// annotatie voor de compiler!
			public void windowClosing(WindowEvent e) {
	public void makeGUI() {
	    try {
	        SwingUtilities.invokeAndWait(new Runnable() {
	          public void run() {
	      } catch (Exception exc) {
	        System.out.println("Can't create because of " + exc);
	public void makeTabs() {
		JTabbedPane tabbedPane = new JTabbedPane();
		tabbedPane.addTab("Personen",  new PersoonPanel(v));
		tabbedPane.setMnemonicAt(0, KeyEvent.VK_1);
		tabbedPane.addTab("Kringen", new KringPanel(v));
		tabbedPane.setMnemonicAt(1, KeyEvent.VK_2);


	//public void update(Observable arg0, Object arg1) {
	//	v = (Vereniging) arg0;
In each of panels there can be changed something. Therefore I have by each class a ActionListener. This ActionListeners changes something in a seperate class, which is also implementing the class Observable.

All classes which extends the JPanel are Observers from this class. So, if anything will change, everything from that panel will be redrawed.

My questions are:
1. Is this architecture oke? Tabs, JPanels on that tabs, nested ActionListeners by the panels, an Observer-architecture?

This, because I have a problem with redrawing. If I change something, it will call the function update from each class. But, then all classes will update and I won't get the information from the right tab for me.