notepad.java

Java中的简单记事本程序

import java.io.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.datatransfer.*;

public class Notepad extends Frame implements ActionListener,MouseListener
	{
		FileDialog fileDlg;
		String str,fileName;
		byte byteBuf[]=new byte[10000];
		Toolkit toolKit=Toolkit.getDefaultToolkit();
		Clipboard clipBoard=toolKit.getSystemClipboard();
		TextArea ta=new TextArea();
		PopupMenu pm=new PopupMenu();
		MenuBar mb=new MenuBar();
		Menu m1=new Menu("文件");
		Menu m2=new Menu("编辑");
		Menu m3=new Menu("工具");
		MenuItem cut2=new MenuItem("剪切");
		MenuItem copy2=new MenuItem("复制");
		MenuItem paste2=new MenuItem("粘贴");
		  
		MenuItem cut=new MenuItem("剪切");
		MenuItem copy=new MenuItem("复制");
		MenuItem paste=new MenuItem("粘贴");
		MenuItem computer=new MenuItem("计算器");
		  
		MenuItem open=new MenuItem("打开");
		MenuItem close=new MenuItem("关闭");
		MenuItem save=new MenuItem("保存");
		MenuItem exit=new MenuItem("退出");

	    Notepad()
			{
				setTitle("简易文件编辑器");
				setSize(400,280);
				add(ta);
				addWindowListener(new WindowAdapter()
					{
						public void windowClosing(WindowEvent e){
						System.exit(0);
					}

								}); 
				m1.add(open);
				m1.add(close);
				m1.add(save);
				m1.addSeparator();

				m1.add(exit);
				m2.add(cut);
				m2.add(paste);
				m2.add(copy);
				m3.add(computer);  
				  
				open.addActionListener(this);
				close.addActionListener(this);
				save.addActionListener(this);
				exit.addActionListener(this);
				  
			    cut.addActionListener(this);
				copy.addActionListener(this);
				paste.addActionListener(this);
				  
				cut2.addActionListener(this);
				copy2.addActionListener(this);
				paste2.addActionListener(this);
				  
				computer.addActionListener(this);
			    mb.add(m1);
				mb.add(m2);
				mb.add(m3);
				pm.add(cut2);
				pm.add(paste2);
				pm.add(copy2);
				ta.add(pm);
				this.setMenuBar(mb);
				ta.addMouseListener(this); 
				setVisible(true);
		  }
		public void actionPerformed(ActionEvent e){
		  
		   if(e.getSource()==exit)
			 System.exit(0);
		   else if(e.getSource()==close)
			 ta.setText(null);
		   else if(e.getSource()==open){
			 fileDlg=new FileDialog(this,"打开文件");
			 fileDlg.show();
			 fileName=fileDlg.getFile();
			 try{
			 FileInputStream in=new FileInputStream(fileName);
			 in.read(byteBuf);
			 in.close();
			 str=new String(byteBuf);
			 ta.setText(str);
			 setTitle("adsad"+fileName);
			 }catch(IOException ioe){}
		   }
		   else if(e.getSource()==save){
			fileDlg=new FileDialog(this,"保存文件",FileDialog.SAVE);
			fileDlg.show();
			fileName=fileDlg.getFile();
			str=ta.getText();
			byteBuf=str.getBytes();
			try{
			 FileOutputStream out=new FileOutputStream(fileName);
			 out.write(byteBuf);
			 out.close();
			}catch(IOException ioe){}
		   }  
		   else if(e.getActionCommand()=="剪切"){  
			 String text=ta.getSelectedText();
			   StringSelection selection=new StringSelection(text);
			   clipBoard.setContents(selection,null);
			   ta.replaceRange("",ta.getSelectionStart(),ta.getSelectionEnd());
			   }     
		   else if(e.getActionCommand()=="复制")
			   {String text=ta.getSelectedText();
			   StringSelection selection=new StringSelection(text);
			   clipBoard.setContents(selection,null);
			   }
		   else if(e.getActionCommand()=="粘贴")
			  {Transferable contents=clipBoard.getContents(this);
			   if(contents==null) return;
			   String text="";
			   try{
					text=(String)contents.getTransferData(DataFlavor.stringFlavor);
				}catch(Exception event){
				}
			   ta.replaceRange(text,ta.getSelectionStart(),ta.getSelectionEnd());
			  } 
		   else if(e.getActionCommand()=="计算器") {
			Runtime r= Runtime.getRuntime();
			try {
			 r.exec("calc");
			} catch (IOException e1) {}
			   }  
		}
		public void mouseReleased(MouseEvent e){
			if(e.isPopupTrigger())
			   pm.show(this,e.getX(),e.getX());
			  }
			public void mouseClicked(MouseEvent e){}
			public void mouseEntered(MouseEvent e){}
			public void mouseExited(MouseEvent e){}
		    public void mousePressed(MouseEvent e){}
		    public static void main(String args[]){
		     new Notepad();
		} 
}