Как мога да поправя грешката си с дублирани деца?

В момента имам проблем с моя код. Имам бутон, който трябва да преминава през списък с масиви ImageView, който съм създал, и да показва 4 карти при всяко натискане. В момента мога да накарам моя бутон "Играй" да работи, основната му функция е просто да покаже картите 1 път и след това да бъде деактивиран. Бутонът „Раздаване“ трябва да показва 4 произволни карти всеки път, когато го натисна, докато всички карти изчезнат. Точно сега мога да го накарам да промени 1 карта 1 път и след това получавам грешка „Дублирани деца“. Знам, че проблемът е свързан с преминаването през едни и същи гранични панели всеки път, но се надявах да получа съвет за добър начин за отстраняване на този проблем. Знам, че това може да включва добра промяна на моя код и това е добре. Благодаря ти!

        import java.io.File;
        import java.util.ArrayList;
        import javafx.scene.image.Image;
        import javafx.scene.image.ImageView;
        import java.util.Collections;
        import java.util.EnumSet;
        import java.util.List;
        import javafx.application.Application;
        import javafx.event.*;
        import javafx.scene.Scene;
        import javafx.scene.control.Button;
        import javafx.stage.Stage;
        import javafx.scene.layout.*;
        import javafx.scene.control.Label;
        import javafx.geometry.*;
        import java.util.*;

        import javafx.scene.Node;
        import javafx.scene.image.Image;
        import javafx.scene.image.ImageView;
        import javafx.scene.paint.Color;

        import javax.swing.*;

public class War extends Application {
    public static void main(String[] args) {
        launch(args);
    }

    List<Integer> deck;
    ArrayList<ImageView> imager = new ArrayList<ImageView>();
    private int roundCounter;
    JButton button = new JButton();

    @Override
    public void start(Stage primaryStage) {
        loadDeck();
        loadCards();
        //Panes
        BorderPane bPain = new BorderPane();
        VBox vBox = new VBox(100);
        vBox.setPadding(new Insets(5, 5, 5, 5));
        HBox buttonBox = new HBox(100);
        buttonBox.setPadding(new Insets(25, 25, 25, 75));
        buttonBox.setStyle("-fx-background-color: blue");


        BorderPane bPain4 = new BorderPane();
        bPain.setLeft(new P1Pane("PLayer 1"));
        bPain4.setRight(new P2Pane("PLayer 2"));
        BorderPane bPain2 = new BorderPane();
        bPain2.setRight(new P3Pane("PLayer 4"));
        bPain2.setLeft(new P4Pane("PLayer 3"));




        BorderPane bPain3 = new BorderPane();
        DeckPane dPane = new DeckPane("Deck");


        bPain3.setCenter(dPane);
        bPain3.setMargin(dPane, new Insets(5, 5, 5, 5));
        bPain3.setCenter(dPane);

        //Buttons
        Button pBtn = new Button("PLAY");
        Button dBtn = new Button("DEAL");
        Button endBtn = new Button("END GAME");
        buttonBox.getChildren().addAll(pBtn, dBtn , endBtn);


        vBox.getChildren().addAll(buttonBox, bPain, bPain3, bPain2, bPain4);


        pBtn.setOnAction(
                p -> {System.out.println("Play pressed");
                loadCards();

            });
        pBtn.setOnAction(new EventHandler<ActionEvent>() {


            public void handle(ActionEvent p) {
                bPain.getChildren().add(imager.get(10));
                bPain4.getChildren().add(imager.get(20));
                bPain2.getChildren().add(imager.get(30));
                bPain3.getChildren().add(imager.get(40));
            }
        });


        dBtn.setOnAction(new EventHandler<ActionEvent>() {


            public void handle(ActionEvent d) {
                for(int i = 0; i<deck.size(); i++){
                //bPain2.getChildren().add(imager.get(i));
                //bPain4.getChildren().add(imager.get(i));
                bPain.getChildren().add(imager.get(i));
                //bPain3.getChildren().add(imager.get(i));
                }
            }
        });

        endBtn.setOnAction(
                e -> {
                    //when pressed, popup asks if sure
                    //disabled after
                    //resets number of wins
                    System.out.println("End pressed");
                });



        //Stage set
        primaryStage.setTitle("WAR!!!");
        //primaryStage.setScene(new Scene(vBox2, 100, 100));
        primaryStage.setScene(new Scene(vBox, 500, 500));

        primaryStage.show();
    }

    public void loadCards() {

        String path = "/users/ebrovski/Desktop/card";
        String files;
        File folder = new File(path);
        Image[] images = new Image[100];
        File[] listOfFiles = folder.listFiles();
        int j = 0;
        for (int i = 0; i < listOfFiles.length; i++) {
            if (listOfFiles[i].getName().endsWith("png")) {
                System.out.println(listOfFiles[i].getAbsolutePath());

                files = "file:" + listOfFiles[i].getAbsolutePath();
                System.out.println(files);

                images[j] = new Image(files, 200, 200, true, true);

                j++;
            }
        }

        for(int k = 0; k < deck.size(); k++) {
            imager.add(new ImageView(images[deck.get(k)]));

        }
    }



    public void loadDeck() {
        deck = new ArrayList<Integer>();
        for(int i =0; i < 52; i++) {
            deck.add(i);
        }
        Collections.shuffle(deck);
    }


    //Player Panes
    class P1Pane extends Pane {

        private void add(ImageView get) {
            throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
        }
        public P1Pane(String player) {
            Label playerTitle = new Label(player);
            getChildren().add(playerTitle);
            setStyle("-fx-border-color: black");
            //setStyle("-fx-background-color: green");
            setPadding(new Insets(75, 1, 1, 1));

           // getChildren().add(imager.get(10));

        }
    }

    class P2Pane extends Pane {
        public P2Pane(String player) {
            Label playerTitle = new Label(player);
            getChildren().add(playerTitle);
            setStyle("-fx-border-color: black");
            //setStyle("-fx-background-color: green");
            setPadding(new Insets(75, 1, 1, 1));
            //getChildren().add(imager.get(20));
        }
    }
    class P3Pane extends Pane {
        public P3Pane(String player) {
            Label playerTitle = new Label(player);
            getChildren().add(playerTitle);
            setStyle("-fx-border-color: black");
            //setStyle("-fx-background-color: green");
            setPadding(new Insets(75, 3, 3, 3));
            //getChildren().add(imager.get(40));

        }
    }

    class P4Pane extends Pane {
        public P4Pane(String player) {
            Label playerTitle = new Label(player);
            getChildren().add(playerTitle);
            setStyle("-fx-border-color: black");
            //setStyle("-fx-background-color: green");
            setPadding(new Insets(75, 3, 3, 3));
            //getChildren().add(imager.get(30));
        }
    }


    //Deck Pane
    class DeckPane extends Pane {
        public DeckPane(String deckName) {
            Label deckTitle = new Label(deckName);
            getChildren().add(deckTitle);

            setStyle("-fx-border-color: black");
            //setStyle("-fx-background-color: forestgreen");
            setPadding(new Insets(75, 3, 3, 3));

        }
    }


}

Сега, когато съм на работния си компютър, получавам различна грешка, свързана с моя loadDeck(); метод. Ето грешката по време на изпълнение: Моля, помогнете!

java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:363)
    at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:303)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
    at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:875)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$147(LauncherImpl.java:157)
    at com.sun.javafx.application.LauncherImpl$$Lambda$49/28230490.run(Unknown Source)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 100
    at war.War.loadCards(War.java:151)
    at war.War.start(War.java:50)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$153(LauncherImpl.java:821)
    at com.sun.javafx.application.LauncherImpl$$Lambda$64/26176767.run(Unknown Source)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$166(PlatformImpl.java:323)
    at com.sun.javafx.application.PlatformImpl$$Lambda$46/11567059.run(Unknown Source)
    at com.sun.javafx.application.PlatformImpl.lambda$null$164(PlatformImpl.java:292)
    at com.sun.javafx.application.PlatformImpl$$Lambda$48/14442382.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$165(PlatformImpl.java:291)
    at com.sun.javafx.application.PlatformImpl$$Lambda$47/30452001.run(Unknown Source)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$141(WinApplication.java:102)
    at com.sun.glass.ui.win.WinApplication$$Lambda$38/2075313.run(Unknown Source)
    ... 1 more