利用数组随机抽取 Java利用数组随机抽取幸运观众怎样实现

package cn.edu.xidian.crytoll;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.JLabel;
import javax.swing.UIManager;
import javax.swing.border.EmptyBorder;
import javax.swing.border.TitledBorder;

public class ArrayExample {

    private JFrame frame;
    private JTextField textField;
    private JScrollPane scrollPane;
    private JLabel label_1;
    JTextArea textArea = new JTextArea();
    private JTextArea textArea_1;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    ArrayExample window = new ArrayExample();
                    window.frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the application.
     */
    public ArrayExample() {
        initialize();
    }

    /**
     * Initialize the contents of the frame.
     */
    private void initialize() {
        frame = new JFrame("利用数组随机抽取幸运观众");
        frame.setBounds(100, 100, 500, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(null);

        JLabel label = new JLabel("\u8F93\u5165\u5728\u573A\u89C2\u4F17\u59D3\u540D\u6309\u56DE\u8F66");
        label.setBounds(10, 10, 132, 15);
        frame.getContentPane().add(label);

        textField = new JTextField();
        textField.addKeyListener(new KeyAdapter() {
            @Override
            public void keyPressed(KeyEvent e) {
                do_textField_keyPressed(e);
            }
        });
        textField.setBounds(10, 35, 132, 21);
        frame.getContentPane().add(textField);
        textField.setColumns(10);

        scrollPane = new JScrollPane();
        scrollPane.setBounds(10, 66, 132, 185);
        frame.getContentPane().add(scrollPane);    

        textArea_1 = new JTextArea();
        scrollPane.setViewportView(textArea_1);

        label_1 = new JLabel("\u9009\u53D6\u89C2\u4F17\u4EBA\u5458\uFF1A");
        label_1.setBounds(180, 10, 132, 15);
        frame.getContentPane().add(label_1);

        
        textArea.setBounds(180, 34, 214, 217);
        frame.getContentPane().add(textArea);

        JButton button = new JButton("\u62BD\u53D6");
        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                do_button_actionPerformed(e);
            }
        });
        button.setBounds(404, 187, 70, 23);
        frame.getContentPane().add(button);

        JButton button_1 = new JButton("\u9000\u51FA");
        button_1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                do_button_1_actionPerformed(e);
            }
        });
        button_1.setBounds(404, 228, 70, 23);
        frame.getContentPane().add(button_1);
    }
    protected void do_textField_keyPressed(KeyEvent e) {
        if (e.getKeyChar() != '\n')// 不是回车字符不做处理
            return;
        String name = textField.getText();
        if (name.isEmpty())// 如果文本框没有字符串不做处理
            return;
        textArea_1.append(name + "\n");// 把输入人名与回车符添加到人员列表
        textField.selectAll();// 选择文本框所有字符
    }
    protected void do_button_actionPerformed(ActionEvent e) {
        String perstring = textArea_1.getText();// 获取人员列表文本
        String[] personnelArray = perstring.split("\n{1,}");// 获取人员数组
        int index = (int) (Math.random() * personnelArray.length);// 生成随机数组索引
        // 定义包含格式参数的中奖信息
        String formatArg = "本次抽取观众人员：\n\t%1$s\n恭喜%1$5s成为本次观众抽奖的大奖得主。"
                + "\n\n我们将为%1$5s颁发：\n\t过期的酸奶二十箱。";
        // 为中奖信息添加人员参数
        String info = String.format(formatArg, personnelArray[index]);
        textArea.setText(info);// 在文本域显示中奖信息
    }
    protected void do_button_1_actionPerformed(ActionEvent e) {
        System.exit(0);
    }
}