✏️ SelectStudent

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.util.*;

class SelectStudent extends Frame implements ActionListener {
	private JLabel lblName;
	private JButton btnStop;
	private JButton btnReset;
	private boolean isStop;
	private Vector<String> names;

	public SelectStudent() {
		super("걸리면~~");
		init();
		setLayout();
		addListener();
		showFrame();
		start();
	}

	private void init() {
		loadStudentList();

		Dimension btnSize = new Dimension(70, 25);

		lblName = new JLabel("ㅋㅋㅋ", JLabel.CENTER);
		lblName.setFont(new Font("Dialog", Font.BOLD, 80));
		btnStop = new JButton("Select");
		btnStop.setPreferredSize(btnSize);
		btnReset = new JButton("Reset");
		btnReset.setPreferredSize(btnSize);
	}

	private void setLayout() {
		add(lblName, BorderLayout.CENTER);
		Panel pnlSouth = new Panel();
		pnlSouth.add(btnStop);
		pnlSouth.add(btnReset);
		add(pnlSouth, BorderLayout.SOUTH);
	}

	private void addListener() {
		btnStop.addActionListener(this);
		btnReset.addActionListener(this);
		addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent we) {
				System.exit(0);
			}
		});
	}

	private void showFrame() {
		setLocation(400, 200);
		setSize(400, 200);
		// pack () ;
		setVisible(true);
	}

	private boolean loadStudentList() {
		try {
			BufferedReader br = new BufferedReader(new FileReader("list.dat"));
			names = new Vector<String>();
			String temp = null;
			while ((temp = br.readLine()) != null) {
				names.add(temp);
			}
			return true;
		} catch (IOException ioe) {
			return false;

		}
	}

	public void actionPerformed(ActionEvent ae) {
		if (ae.getSource() == btnStop) {
			isStop = !isStop;
			if (!isStop) {
				start();
			}
		} else {
			loadStudentList();
			lblName.setText("다시 !!!");
		}
	}

	private void start() {
		Thread t = new Thread(new RandomList(this));
		t.start();
	}

	public void setName(String name) {
		lblName.setText(name);
	}

	public boolean isStop() {
		return isStop;
	}

	public Vector<String> getNames() {
		return names;
	}

	public void setNames(Vector<String> names) {
		names = names;
	}

	public static void main(String[] args) {
		new SelectStudent();
	}
}

✏️ RandomList

import java.io.*;
import java.util.*;

class RandomList implements Runnable {
    private Vector<String> names;
    private SelectStudent owner;

    public RandomList(SelectStudent owner) {
        this.owner = owner;
        names = owner.getNames();

        if (names == null) {
            System.exit(0);
        }
    }
    public void run() {
    	
        try {
            int idx = 0;
            String name = "";
            while (!owner.isStop()) {
                Thread.sleep(30);
                name = names.get(idx++);
                owner.setName(name);

                if (idx == names.size()) {
                    idx = 0;
                }
            }
            names.remove(name);
            Collections.shuffle(names);
        } catch (Exception e) {}
    }
}