JButtons not appearing problem

Question

Hi,
First of all I am using NetBeans environement.
I have just started writing short menu program.I am creating two panes,in the southern on I intend to put four buttons,unfortunately when i click compile these buttons sometimes seems to appear but usaully nothing apart from background images seems to be appear.Please help me solve my problem.Thanks in advance.
My code:
Main:
package q;
import javax.swing.*;
import java.awt.*;
import java.awt.geom.*;
import java.awt.event.*;
import java.util.*;
* @author Piotr
public class Main {
     * @param args the command line arguments
    public static void main(String[] args) {
        GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();
        Rectangle b =env.getMaximumWindowBounds();
        System.out.println(b);
        Ramka pierwsza = new Ramka(b);
        pierwsza.setVisible(true);
        pierwsza.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}Ramka (Frame ) code:
package q;
import javax.swing.*;
import java.awt.*;
import java.awt.geom.*;
import java.awt.event.*;
import java.util.*;
import java.awt.image.BufferStrategy;
class Ramka extends JFrame{
        private Panel_wstepny panel_wstepny;
        private Panel_wstepny_g panel_wstepny_g;
        //public static final int szer =800;
        //public static final int wys= 700;
        public Ramka(Rectangle k)
           Dimension j = k.getSize();
           j.setSize((int)(k.width*0.3),(int)(0.7*k.height));
           this.setSize(j.getSize());
           setTitle("Asteroids");
           setLayout(new BorderLayout());
           panel_wstepny=new Panel_wstepny();
           panel_wstepny_g=new Panel_wstepny_g();
           panel_wstepny.setPreferredSize(new Dimension (j.width,(int)(j.height*0.3)));
           panel_wstepny.setPreferredSize(new Dimension (j.width,(int)(j.height*0.7)));
           this.add(panel_wstepny_g,BorderLayout.CENTER);
           this.add(panel_wstepny,BorderLayout.SOUTH);
}Panel_wstepny_g:
package q;
import javax.swing.*;
import java.awt.*;
import java.awt.geom.*;
import java.awt.event.*;
import java.util.*;
class Panel_wstepny_g extends JPanel {
    Image tlo =Toolkit.getDefaultToolkit().getImage("tytul_big.gif");
    Dimension size;
            private Image doubleBuffer;
        public void update(Graphics g) {
            Dimension size = getSize();
            if (doubleBuffer == null ||doubleBuffer.getWidth(this) != size.width ||doubleBuffer.getHeight(this) != size.height)
                    doubleBuffer = createImage(size.width, size.height);
            if (doubleBuffer != null)
                Graphics g2 = doubleBuffer.getGraphics();
                paint(g2);
                g2.dispose();
                g.drawImage(doubleBuffer, 0, 0, null);
            else
                paint(g);
    public void paint(Graphics g){
        size=getSize();
        Graphics2D g2=(Graphics2D)g;
        super.paintComponent(g);
        setBackground(Color.BLACK);
        Image z2=tlo.getScaledInstance((int)(0.55*size.width),(int)(0.8*size.height),Image.SCALE_FAST);
        MediaTracker trop = new MediaTracker(this);
        trop.addImage(z2,0);
        try { trop.waitForID(0);}
        catch(InterruptedException exception) {}
        g.drawImage(z2,(int)(0.2*size.width),(int)(0.05*size.height),null);
}Panel wstepny(HERE I NEED TO PUT THESE BUTTONS ,BUT IAS I HAVE ALREADY WRITTEN ,WHEN I PRESS COMPILE sometimes they does appear,but usually nothing appears,aprat form background)
package q;
import javax.swing.*;
import java.awt.*;
import java.awt.geom.*;
import java.awt.event.*;
import java.util.*;
class Panel_wstepny extends JPanel {
    Dimension size;
    Image tlo;
    JButton nowa;
    JButton koniec;
    JButton autor;
    JButton info;
public Panel_wstepny(){
     //GridLayout b2 =new GridLayout(200,0);
     setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
    nowa=new JButton  (" Nowa gra ");
    koniec=new JButton("Koniec gry");
    autor=new JButton ("  Autorzy  ");
    info=new JButton  ("   Pomoc   ");
     tlo =Toolkit.getDefaultToolkit().getImage("background.gif");  
    public void paint(Graphics g){
             size =getSize();
         //  add(Box.createVerticalStrut((int)(size.height/4)));         
add(Box.createHorizontalStrut((int)(size.width/50)));
//add(Box.createRigidArea(new Dimension(size.width/4,size.height)));
          add(nowa);
add(Box.createVerticalStrut((int)(size.height/20)));
add(koniec);
add(Box.createVerticalStrut((int)(size.height/20)));
add(autor);
add(Box.createVerticalStrut((int)(size.height/20)));
add(info);
        System.out.println(size);
        Graphics2D g2=(Graphics2D)g;
        super.paintComponent(g);
        Image z2=tlo.getScaledInstance(this.size.width,this.size.height,Image.SCALE_FAST);
          MediaTracker trop = new MediaTracker(this);
          trop.addImage(z2,0);
          try { trop.waitForID(0);}
          catch(InterruptedException exception) {}
          g.drawImage(z2,0,0,null);
}

Answer 1

There are so many thing wrong with your program I don't know where to start.
a) never override the update() method. (that is an old AWT trick)
b) newver override the paint() method (see above comment)
c) if you do override the paint() method, then why would you invoke super.paintComponent()? The idea of using super.() is to invoke the parent method of the method you are overriding.
d) don't use a MediaTracker in the paint() method. The IO to read the image should only be done once.
e) don't use a BufferStrategy. Swing is double buffered by default.
f) if you are trying to use a "background image" then search the forum using those words as the search keywords. This question is asked and answered all the time.
I suggest you start by read the [Swing Tutorial|http://java.sun.com/docs/books/tutorial/uiswing/TOC.html]. There is a section on "Custom Painting" as well as examples of adding buttons to a frame.