[java实战篇]--java的GUI(1)

给出一个实例即可：

package mymenu;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
public class MyMenuTest
{
    private Frame f;
    private MenuBar bar;
    private TextArea ta;
    private Menu fileMenu;
    private MenuItem openItem,saveItem,closeItem;
    private FileDialog openDia,saveDia;
    private File file;
    MyMenuTest()
    {
        init();
    }
    public void init()
    {
        f = new Frame("my window");
        f.setBounds(300,100,650,600);
        bar = new MenuBar();
        ta = new TextArea();
        fileMenu = new Menu("文件");
            
        openItem = new MenuItem("打开");
        saveItem = new MenuItem("保存");
        closeItem = new MenuItem("退出");
            
        fileMenu.add(openItem);
        fileMenu.add(saveItem);
        fileMenu.add(closeItem);
        bar.add(fileMenu);
        f.setMenuBar(bar);
        openDia = new FileDialog(f,"我要打开",FileDialog.LOAD);
        saveDia = new FileDialog(f,"我要保存",FileDialog.SAVE);
        f.add(ta);
        myEvent();
        f.setVisible(true);
    }
    private void myEvent()
    {
        saveItem.addActionListener(new ActionListener()
        {
            
            public void actionPerformed(ActionEvent e)
            {
                if(file==null)
                {
                    saveDia.setVisible(true);
                    String dirPath = saveDia.getDirectory();
                    String fileName = saveDia.getFile();
                    if(dirPath==null || fileName==null)
                        return ;
                    file = new File(dirPath,fileName);
                }
                try
                {
                    BufferedWriter bufw  = new BufferedWriter(new FileWriter(file));
                    String text = ta.getText();
                    bufw.write(text);
                    //bufw.flush();
                    bufw.close();
                }
                catch (IOException ex)
                {
                    throw new RuntimeException();
                }
                    
            }
        });
        openItem.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                openDia.setVisible(true);
                String dirPath = openDia.getDirectory();
                String fileName = openDia.getFile();
//              System.out.println(dirPath+"..."+fileName);
                if(dirPath==null || fileName==null)
                    return ;
                ta.setText("");
                file = new File(dirPath,fileName);
                try
                {
                    BufferedReader bufr = new BufferedReader(new FileReader(file));
                    String line = null;
                    while((line=bufr.readLine())!=null)
                    {
                        ta.append(line+"\r\n");
                    }
                    bufr.close();
                }
                catch (IOException ex)
                {
                    throw new RuntimeException("读取失败");
                }
            }
        });
        closeItem.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                System.exit(0);
            }
        });
        f.addWindowListener(new WindowAdapter()
        {
            public void windowClosing(WindowEvent e)
            {
                System.exit(0);
            }
        });
    }
        
    public static void main(String[] args)
    {
        new MyMenuTest();
    }
}