collection.shuffle does not work in java netbeans 8.2

I am trying to shuffle JButton using collections.shuffle(),but it does not work when I run the program…

this is my code :

 /*
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     * To change this template file, choose Tools | Templates
     * and open the template in the editor.
     */
    package projetu;
    
    import java.awt.*;
    import java.util.*;
    
    /**
     *
     * @author USER
     */
    public class NewMain extends JFrame{
    
        /**
         * @param args the command line arguments
         */
        
           final int row =3;
           final int col =3;
           javax.swing.JPanel panel;
           javax.swing.JButton button[];
           List<javax.swing.JButton> arrlist = new ArrayList();

        public NewMain (){
            panel = new javax.swing.JPanel();
            panel.setLayout(new GridLayout(row,col));
            
        button = new javax.swing.JButton[9];
        for (int i=0; i<9; i++){
            
            button[i] = new javax.swing.JButton(String.valueOf(i));
            panel.add(button[i]);
        
        arrlist.add(button[i]);
        
        Collections.shuffle(arrlist);
       
        }
        
        
        add(panel);
        setSize(300,300);
        setVisible(true);
        } //end of script 0001
        
             public static void main(String[] args) {
            // TODO code application logic here
            
            NewMain n=new NewMain();
                   
        
    }            
    
    
    }
//