import javax.swing.*;public class Example9_16 public static void main(String args) WindowMess win=new WindowMess();win.setTitle(带消息对话框的窗口);win.setBounds(80,90,200,300);import java.awt.event.*;import java.awt.*;import javax.swing.*;public class WindowMess extends JFrame implements ActionListenerJTextField inputEnglish;JTextArea show;String regex=a-zZ-Z+;WindowMess()inputEnglish=new JTextField(22);inputEnglish.addActionListener(this);show=new JTextArea();add(inputEnglish,BorderLayout.NORTH);add(show,BorderLayout.CENTER);setVisible(true);setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);public void actionPerformed(ActionEvent e)if(e.getSource()=inputEnglish)String str=inputEnglish.getText();if(str.matches(regex)show.append(str+,);else/弹出“警告”消息对话框JOptionPane.showMessageDialog(this,您输入了非法字符,小心对话框,JOptionPane.WARNING_MESSAGE);inputEnglish.setText(null);