java上机第十五周任务一

青旅半醒 2022-05-13 11:56 270阅读 0赞

/*  
    * 程序头部注释开始    
    * 程序的版权和版本声明部分    
    * Copyright (c) 2011, 烟台大学计算机学院学生    
    * All rights reserved.    
    * 文件名称：打开和保存文件                            
    * 作    者：薛广晨                                
    * 完成日期：2012  年12 月 6日    
    * 版 本号：x1.0             
        
    * 对任务及求解方法的描述部分    
    * 输入描述：   
    * 问题描述:     
    * 程序输出：    
    * 程序头部的注释结束  
    */
    
    package xue;
    
    import java.awt.*;
    import java.awt.event.*;
    import java.io.*;
    
    public class Mymenu {
    	private Frame f;
    	private MenuBar bar;
    	private TextArea ta;
    	private Menu fileMenu;
    	private MenuItem openItem, saveItem, closeItem;
    	
    	private FileDialog openDia, saveDia; 
    	
    	private File file;
    	
    	Mymenu()
    	{
    		init();
    	}
    
    	private void init() {
    		// TODO Auto-generated method stub
    		f = new Frame("带文件对话框的窗口");
    		f.setBounds(300, 100, 650, 600); 
    		bar = new MenuBar();
    		ta = new TextArea();
    		fileMenu = new Menu("文件");
    		
    		openItem = new MenuItem("打开文件");
    		saveItem = new MenuItem("保存文件");
    		closeItem = new MenuItem("退出");
    		
    		fileMenu.add(openItem);
    		fileMenu.add(saveItem);
    		fileMenu.add(closeItem);
    		
    		bar.add(fileMenu);
    		f.setMenuBar(bar);
    		
    		openDia = new FileDialog(f, "打开文件对话框", FileDialog.LOAD);
    		saveDia = new FileDialog(f, "保存文件对话框", FileDialog.SAVE);
    		
    		f.add(ta);
    		myEvent();
    		f.setVisible(true);
    	}
    
    	private void myEvent() {
    		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);
    				BufferedReader bufr = null;
    				try
    				{
    					bufr = new BufferedReader(new FileReader(file));
    					String line = null;
    					while((line = bufr.readLine()) != null)
    					{
    						ta.append(line + "\r\n");
    					}
    					
    				}
    				catch(IOException ex)
    				{
    					throw new RuntimeException("读取失败");
    				}
    				finally
    				{
    					try {
    						bufr.close();
    						} catch (IOException e1) {}
    				}
    			}	
    		});	
    		
    		saveItem.addActionListener(new ActionListener()
    		{
    			BufferedWriter bufw;
    			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
    				{
    					bufw = new BufferedWriter(new FileWriter(file));
    					String text = ta.getText();
    					bufw.write(text);
    					bufw.flush();
    				}
    				catch(IOException ex)
    				{
    					throw new RuntimeException("读取失败");
    				}
    				finally
    				{
    					try {
    						bufw.close();
    						} catch (IOException e1) {}
    				}
    			}
    		});
    		
    		closeItem.addActionListener(new ActionListener()
    		{
    			public void actionPerformed(ActionEvent e) {
    				System.exit(0);
    			}	
    		});
    		
    		f.addWindowListener(new WindowAdapter()  
    		{  
    			public void windowClosing(WindowEvent e)  
    		    {  
    				System.exit(0);   
    		    }  
    		});
    
    	}
    }