Problem in displaying Icon on JButton

Question

Hi,
I have a problem ..
In my program I have to set Icon for a Jbutton and wait for 2 secs and then remove the Icon..
I used jb.setIcon(Imageicon) (jb is button reference) to set the icon and jb.setIcon(null) to remove Icon
Now no Icon is displayed on the button at all....
My code looks like below mentioned
jb.setIcon(Imageicon)
Thread.sleep(2000);
jb.setIcon(null)
plz reply mee at the earliest...

Answer 1

the code snipped is like this..
the below mentioned code is in actionPerformed method
pres.setIcon(iial.get(Integer.parseInt(pres.getName())));  //icon for prev is already set
          System.out.println("Icon for pres is set now");
// need to wait for 2 seconds before both the icons are set to null
          prev.setIcon(null);
          pres.setIcon(null);Here prev and pres are references to JButtons.
I tried the swing timers but couldnt succeed (i might be implemented them in an incorrect way coz im not familiar with them)
plz cud you provide me with am example program or a solution to above scenario in a program.....
Here is the actual program if you want you can run it with keeping atleast 9 images in tn folder and changing maxpics value to 9
Game.java
package com;
//Concentration Game
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Collections;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Game extends JFrame implements ActionListener {
     private static final long serialVersionUID = 1L;
     public static void main(String args[]) throws InterruptedException,
               InvocationTargetException {
System.out.println();
SwingUtilities.invokeLater(new Runnable() {
    public void run() {
         Game cg = new Game();
          cg.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     Logic logic;
     private int[][] arr;
     private Container contents;
     private JLabel controlLabel;
     private JPanel controlPanel;
     private JButton[][] gameBoardLabel;
     private JPanel gamePanel;
     private ArrayList<ImageIcon> iial;
     private boolean isNewAction = true, isFirstAction = true;
     private JButton prev, pres;
     private long s_time, e_time, t_time;
     private int SIZE, arrvalue, maxpics = 51, pairscount, no_of_pairs;
     public Game() {
          super("Concentration Game");
          logic = new Logic();
          logic.populateArray();
          logic.shuffle();
          logic.printArray();
          arr = logic.getArray();
          SIZE = logic.getSize();
          no_of_pairs = (SIZE * SIZE) / 2;
          iial = new ArrayList<ImageIcon>();
          for (int i = 1; i <= maxpics; i++) {
               iial.add(new ImageIcon(this.getClass().getClassLoader()
                         .getResource("tn/image" + i + ".jpg")));
          Collections.shuffle(iial);
          System.out.println("Completed loading images");
          contents = getContentPane();
          contents.setLayout(new BorderLayout());
          gameBoardLabel = new JButton[SIZE][SIZE];
          new JPanel();
          gamePanel = new JPanel();
          controlPanel = new JPanel();
          gamePanel.setLayout(new GridLayout(SIZE, SIZE, 5, 5));
          controlLabel = new JLabel("Game not started");
          for (int r = 0; r < gameBoardLabel.length; r++) {
               for (int c = 0; c < gameBoardLabel[r].length; c++) {
                    arrvalue = arr[r][c];
                    System.out.println(arrvalue);
                    if (arr[r][c] == 0) {
                         gameBoardLabel[r][c] = new JButton();
                         gameBoardLabel[r][c].setEnabled(false);
                    else
                         gameBoardLabel[r][c] = new JButton();
                    gameBoardLabel[r][c].addActionListener(this);
                    gameBoardLabel[r][c].setName("" + arrvalue);
                    gameBoardLabel[r][c].setPressedIcon(iial.get(arrvalue));
                    gamePanel.add(gameBoardLabel[r][c]);
          controlPanel.add(controlLabel);
          contents.add(gamePanel, BorderLayout.CENTER);
          contents.add(controlPanel, BorderLayout.SOUTH);
          setSize(400, 500);
          setVisible(true);
          System.out.println(this);
     @Override
     public void actionPerformed(ActionEvent e) {
          JButton jb = (JButton) e.getSource();
          // System.out.println(jb.getName());
          System.out.println(e.getSource());
          if (isFirstAction) {
               controlLabel.setText("Game Started");
               s_time = System.currentTimeMillis();
               isFirstAction = false;
               System.out.println(this);
          if (isNewAction) {
               prev = pres = jb;
               jb.setIcon(iial.get(Integer.parseInt(jb.getName())));
               isNewAction = false;
               return;
          prev = pres;
          pres = jb;
          if (pres == prev)
               return;
          if (pres.getName().equals(prev.getName())) {
               pres.setIcon(iial.get(Integer.parseInt(pres.getName())));
               pres.removeActionListener(this);
               prev.removeActionListener(this);
               controlLabel.setText("pair matched");
               resetAttributes();
               System.out.println("haha----last count==" + ++pairscount);
               if (pairscount == no_of_pairs) {
                    e_time = System.currentTimeMillis();
                    t_time = (e_time - s_time) / 1000;
                    controlLabel.setText("Game Over in " + t_time + " secs");
                    System.out.println("done");
          System.out.println(pres);
          pres.setIcon(iial.get(Integer.parseInt(pres.getName())));
          controlLabel.setText("pair didn't match");
          System.out.println("pres is set now");
          prev.setIcon(null);
          pres.setIcon(null);
          resetAttributes();
     private void resetAttributes() {
          prev = pres = null;
          isNewAction = true;
Logic.java
package com;
import java.util.ArrayList;
import java.util.Collections;
import javax.swing.JOptionPane;
public class Logic{
      ArrayList<Integer> al;
      int arr[][],arrlist[][],elements=1;
      int SIZE;
int[][] getArray()
          return arrlist;
int getSize(){
     return SIZE;
public static void main(String args[]){
     Logic logic =new Logic();
            logic.populateArray();
           logic.shuffle();
           logic.printArray();
           //System.out.println(logic.elements);
void populateArray(){
     String input=JOptionPane.showInputDialog(null,"Enter Size of the array (less than 11)" );
     SIZE=Integer.parseInt(input);
     int cnt = 0;
     arrlist=new int[SIZE][SIZE];
     al=new ArrayList<Integer>();
     for (int r = 0; r < SIZE; r++)
          for (int c = 0; c < SIZE; c++)
               al.add(elements);
               cnt++;
               if (cnt == 2)
                    cnt = 0;
                    elements++;
public  void printArray() {
     for (int i = 0; i < SIZE; i++)
      for (int j = 0; j < SIZE; j++)
        arrlist[i][j] = al.get(j + i * SIZE);
        System.out.print(" "+arrlist[i][j]);
      System.out.println();
public  void shuffle() {
          Collections.shuffle(al);
     if(SIZE%2!=0)
          int cindex=(SIZE*SIZE)/2; //center index
          int celement=al.get(cindex); //center element
          int lindex=al.indexOf(elements); //index of large element
          //al.remove(cindex);
          //al.add(cindex, 0);
          al.remove(lindex);
          al.add(lindex, celement);
          al.remove(cindex);
          al.add(cindex, 0);
}