题目： 用个String数组存储观众（定最大为100），观众名字显示用JTextArea完成，右边中奖信息用带滚轮的JTextArea完成，加入观众用JTextField完成。 留坑： 1、JTable的使用； 2、String里的format()方法； 3、random的使用 4、Vector的使用 代码如下：
import javax.swing.*; import java.awt.*; import java.awt.event.*; import java.util.Random; import java.util.Vector; class Test extends JFrame implements ActionListener, KeyListener { JButton select, exit; JTextArea customer, reward; JTextField add_customer; String name_list[] = {"Jhon", "Bob", "Tom", "Spyciy", "Brother Xiang"}; Vector list = new Vector(); public Test() { for(int i = 0; i < name_list.length; i ++) list.add(name_list[i]); select = new JButton("Select"); exit = new JButton("Exit"); select.addActionListener(this); exit.addActionListener(this); select.setMaximumSize(new Dimension(10, 20)); exit.setMaximumSize(new Dimension(10, 20)); reward = new JTextArea(); reward.setSize(100, 100); JPanel p1 = new JPanel(new GridLayout(3, 1)); p1.add(reward); p1.add(select); p1.add(exit); add_customer = new JTextField(10); add_customer.addKeyListener(this); customer = new JTextArea(); customer.setSize(300, 300); for(int i = 0; i < name_list.length; i ++) customer.append(name_list[i] + "\n"); JScrollPane jsp = new JScrollPane(customer); JPanel p2 = new JPanel(new GridLayout(2, 1)); p2.add(add_customer); p2.add(jsp); Container content = this.getContentPane(); setLayout(new GridLayout(1, 2)); setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); content.add(p2); content.add(p1); setSize(400, 400); setVisible(true); } public void actionPerformed(ActionEvent e) { if(e.getSource() == select) { int s = (int)(Math.random() * list.size()); String temp = list.elementAt(s) + " are rewarded!!!"; reward.setText(temp); } else if(e.getSource() == exit) System.exit(0); } public void keyPressed(KeyEvent e) { if(e.getKeyChar() != '\n') return ; String name = add_customer.getText(); list.add(name); customer.append(list.elementAt(list.size() - 1) + "\n"); add_customer.setText(""); } public void keyReleased(KeyEvent e){} public void keyTyped(KeyEvent e){} public static void main(String arg[]) { new Test(); } }