SetText不显示来自不同类的预期String

Question

我正在尝试将JLabel的文本设置为应用程序编译中的某些内容，程序编译正常，我检查我的数组以查看值是否存在，但JLabel不会更新。确保初始化JLabel。

FileHandling Class

import java.io.*;
import java.nio.charset.Charset;
import java.nio.file.*;
import java.util.Arrays;
import java.util.List;

public class FileHandling {

    private final String getWorkingDirectory = System.getProperty("user.dir"));
    private final String filePath = "/src/files/", fileName = "gameStats.json";
    private final String fullPath = getWorkingDirectory + filePath + fileName;

    private DieIntGUI dieIntGUI = new DieIntGUI("");

    private List<String> score;

    public void isCreated() throws IOException {

        if (!Files.exists(Paths.get(fullPath))) {
            Files.createFile(Paths.get(fullPath));
            BufferedWriter bw = new BufferedWriter(new FileWriter(fullPath));
            bw.write("0|0");
            bw.close();
        } else {
            System.out.printf("File %s already exists\n", fileName);
        readFromFile();
        }

    }

    private void readFromFile() {
        try {
            score = Arrays.asList(Files.readAllLines(Paths.get(fullPath), Charset.defaultCharset()).get(0).split("\\|"));

            System.out.println(score);

            dieIntGUI.playerWins.setText("Player wins: " + score.get(0).toString());


        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

DieIntGUI班

import javax.swing.*;
import java.awt.*;
import java.io.IOException;

public class DieIntGUI extends JFrame {

    public DieIntGUI(String title) {
        super(title);
        setSize(700, 700);
        getContentPane().setBackground(Color.white);
        setLayout(new BorderLayout());
        initComponents();
        add(panel);
        add(errorMessages, BorderLayout.SOUTH);
        setLocationRelativeTo(null);

    }

    public static void main(String[] args) throws IOException {
        DieIntGUI frame = new DieIntGUI("Dice Game");
        frame.setVisible(true);
        FileHandling handle = new FileHandling();
        handle.isCreated();
    }

    private void initComponents() {
        panel = new JPanel();
        errorMessages = new JLabel();
        playerWins = new JLabel("");
        computerWins = new JLabel("");

        drawComponents();
    }


    private void drawComponents() {

        GridBagConstraints gbc = new GridBagConstraints();

        panel.setLayout(new GridBagLayout());
        panel.setSize(700, 700);
        panel.setBackground(Color.white);

        gbc.gridx = 1;
        gbc.gridy = 1;
        gbc.weightx = 1;
        gbc.insets = new Insets(10,10,10,10);
        gbc.anchor = GridBagConstraints.EAST;
        panel.add(playerWins, gbc);

        gbc.gridx = 1;
        gbc.gridy = 2;
        gbc.weightx = 1;
        gbc.anchor = GridBagConstraints.EAST;
        panel.add(computerWins, gbc);


    }

    private JPanel panel;
    private JLabel errorMessages;
    public JLabel playerWins, computerWins;


}