package myMenu;

import java.awt.FileDialog;
import java.awt.Frame;
import java.awt.Menu;
import java.awt.MenuBar;
import java.awt.MenuItem;
import java.awt.TextArea;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class MyMenu {
	private Frame f;
	private MenuBar mb;
	private Menu m;
	private TextArea ta;
	private MenuItem openItem,saveItem,closeItem;
	private FileDialog openDia,saveDia;
	private File file;
	MyMenu()
	{
		init();
	}
	public void init()
	{
		f=new Frame("my window");
		f.setBounds(300, 100, 650, 600);
		f.setVisible(true);
		mb=new MenuBar();
		ta=new TextArea();
		m=new Menu("文件");
		openItem=new MenuItem("打开");
		saveItem=new MenuItem("保存");
		closeItem=new MenuItem("退出");
		
		m.add(openItem);
		m.add(saveItem);
		m.add(closeItem);
		mb.add(m);
		
		myEven();
		openDia=new FileDialog(f,"我要打开",FileDialog.LOAD);
		saveDia=new FileDialog(f,"我要保存",FileDialog.SAVE);
		f.setMenuBar(mb);
		f.add(ta);
	}
	
	private void myEven()
	{
		openItem.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				openDia.setVisible(true);
				String dirPath=openDia.getDirectory();
				String fileName=openDia.getFile();
				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 (Exception e1) {
					throw new RuntimeException("读取失败");
				}
			}
		});
		
		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);
				}
					BufferedWriter buf;
					try {
						buf = new BufferedWriter(new FileWriter(file));
						String text=ta.getText();
						buf.write(text);
						buf.flush();
						buf.close();
					} catch (IOException e1) {
						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 MyMenu();
	}
}