I want to do the process of placing the card down after pressing the button to place the Java Swing card down.

gameDate.getCard_one().setOpen(false);
gameDate.getCard_two().setOpen(false);
gameDate.setCard_one(null); // Reset Card_one
gameDate.setCard_two(null); // Reset Card_two

package pair_matching;

import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

import javax.swing.JoptionPane;

public class Cardclick_Listener implements MouseListener{
    private CardLabel card_label;
    private GameDate gameDate;
    private CardList cardList;
    
    publicCardclick_Listener(CardLabel card_label, GameDate gameDate, CardList cardList) {
        This.card_label=card_label;
        This.gameDate=gameDate;
        This.cardList =cardList;
    }
    
    @ Override
    public void mouseClicked (MouseEvente) {
        boolean open=card_label.isOpen();
        int Pair=gameDate.getPairCount();
        
        // card face-to-face check
        if(open==true){
            ; // Don't turn it on the back
        } else if (open==false) {
            card_label.setOpen(true);
            if(gameDate.getCard_one()==null){
                // null —Stored in Card_one in GameDate
                gameDate.setCard_one(card_label);
                return;
            } else {
                // non-null: stored in Card_two in GameDate
                gameDate.setCard_two(card_label);
            }
        }
    
        /* Pairing*/
        if(gameDate.getCard_two().getNumber()==gameDate.getCard_one().getNumber()){
            if(open==true){
                gameDate.setPairCount(Pair+=0);// Prevents 2 from being counted when pressing a card in the table
            } else {
                /* Conditions for clearing the game
                 * Clear when 52 sheets are ready
                 * */
                gameDate.setPairCount (Pair+=2); // Count the number of sheets
                gameDate.setCard_one(null); // Reset Card_one
                gameDate.setCard_two(null); // Reset Card_two
                
                if(Pair==52){
                    intoption=JoptionPane.showConfirmDialog(null, "GAME CREA!!!" Press Yes to resume the game.", "GAME CREA", JOPTIONPane.YES_NO_OPTION, JOPTIONPane.PLAIN_MESSAGE);
                    if(option==JoptionPane.YES_OPTION){
                        cardList.Restart_cards(); // Turn all cards to the back
                        gameDate.setPairCount(0); // Reset Count Count
                    } else {
                        System.exit(0);// End of Game
                    }
                }
            }
            /* Pair failed*/
        } else {
            /*
             * Added action to activate cardList revers_btn
             * */
            int missmatch=JOptionPane.showConfirmDialog(null,"Cards do not match.", "Card mismatch", JoptionPane.OK_CANCEL_OPTION, JoptionPane.PLAIN_MESSAGE);
            if(missmatch==JoptionPane.OK_OPTION){
                cardList.revers_btn.setEnabled(true);
            } else {
                return;
            }
            
            /*
             * Added action when cardList revers_btn is pressed
             * */
            
            // Return Card_one and Card_two to the back
            
            
        }
    }

    @ Override
    public void mousePressed (MouseEvent) {
    }
    @ Override
    public void mouseReleased (MouseEvent) {
    }
    @ Override
    public void mouseEntered (MouseEvent) {
    }
    @ Override
    public void mouseExited (MouseEvent) {
    }

}

package pair_matching;

import java.awt.Dimension;
import java.util.ArrayList;
import java.util.Collections;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JPanel;

public class CardList extensions JPanel {
    private GameDate gameDate = new GameDate();
    JButton reverses_btn;
    
    // List Labels - > Set ImageIcon for each label in the list - > Collect List Shuffle
    boolean flg = false;
    
    final int club = 0;
    final int diamond = 1;
    final int heart = 2;
    final int spade=3;
    
    /* Card image*/
    // reverse side
    ImageIcon card_back=new ImageIcon("image/card_back.png");
    // surface
    ImageIcon[][]card_array=new ImageIcon[4][13];
    String filename;
    
    // the number of j
    int[] number = {
        1,2,3,4,5,6,7,8,9,10,11,12,13,
        1,2,3,4,5,6,7,8,9,10,11,12,13,
        1,2,3,4,5,6,7,8,9,10,11,12,13,
        1,2,3,4,5,6,7,8,9,10,11,12,13
    };
    
    // List cards
    ArrayList<CardLabel>cards=new ArrayList<>();
    
    publicCardList(){
        setPreferredSize (new Dimension (1150,600));
        Start_card_list();
        Revers_button();
    }
    
    public void Start_card_list(){
        // Card_image
        for(inti=0;i<card_array.length;i++){
            for(int j=0;j<card_array[i].length;j++){
                filename = "image/card";
                switch(i){
                case club:
                    filename = filename + "_club_";
                    break;
                case diamond:
                    filename = filename + "_diamond_";
                    break;
                case heart:
                    filename = filename + "_heart_";
                    break;
                case spade:
                    filename = filename + "_spade_";
                    break;
                }
                // Add a number to the file name -> Add an extension
                filename = String.format(filename + "%02d", j+1);
                filename = filename + ".png";
                card_array[i][j] = new ImageIcon(filename);
                CardLabel tmp_label = new CardLabel(card_array[i][j], card_back, number[j]);
                // If you press tmp_label, the tmp_label turns over.
                tmp_label.addMouseListener(new Cardclick_Listener(tmp_label, gameDate, this));
                add(tmp_label);
                cards.add(tmp_label);
                Collections.shuffle (cards);
            }
        }
        // card shuffle
        for (CardLabel card_shuffle:cards) {
            add(card_shuffle);
        }
    }
    
    // Turn the card to the back when restarting.
    public void Restart_cards() {
        for(inti=0;i<cards.size();i++){
            cards.get(i).setOpen(flg);
        }
    }

    // a button on which a card is placed down
    public void Revers_button(){
        revers_btn = new JButton("Card Down";
        revers_btn.setEnabled(false);
        add(revers_btn);
    }
}