example10_9.java

java小程序

import java.awt.*;
import java.io.*;
import java.awt.event.*;
public class Example10_9
{
public static void main(String args[])
{
FileWindows win=new FileWindows();
}
}
class FileWindows extends Frame implements ActionListener 
{
FileDialog filedialog_save,filedialog_load;
MenuBar menubar;
Menu menu;
MenuItem itemOpen,itemSave;
TextArea text;
BufferedReader in;
FileReader file_reader;
BufferedWriter out;
FileWriter tofile;
FileWindows()
{
super("带文件对话框的窗口");
setSize(260,270);
setVisible(true);
menubar=new MenuBar();
menu=new Menu("文件");
itemOpen=new MenuItem("打开文件");
itemSave=new MenuItem("保存文件");
itemOpen.addActionListener(this);
itemSave.addActionListener(this);
menu.add(itemOpen);
menu.add(itemSave);
menubar.add(menu);
setMenuBar(menubar);
filedialog_save=new FileDialog(this,"保存文件对话框",FileDialog.SAVE);
filedialog_load=new FileDialog(this,"打开文件对话框",FileDialog.LOAD);
filedialog_save.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
filedialog_save.setVisible(false);
}
}
);
filedialog_load.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
filedialog_load.setVisible(false);
}
}
);
addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
}
);
text=new TextArea(10,10);
add(text,BorderLayout.CENTER);
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==itemOpen)
{
filedialog_load.setVisible(true);
text.setText(null);
String s;
if(filedialog_load.getFile()!=null)
{
try{
File file=new File(filedialog_load.getDirectory(),filedialog_load.getFile());
file_reader=new FileReader(file);
in=new BufferedReader(file_reader);
while((s=in.readLine())!=null)
{
text.append(s+"\n");
}
in.close();
file_reader.close();
}
catch(IOException e2){}
}
}
else if(e.getSource()==itemSave)
{
filedialog_save.setVisible(true);
if(filedialog_save.getFile()!=null)
{
try{
File file=new File(filedialog_save.getDirectory(),filedialog_save.getFile());
tofile=new FileWriter(file);
out=new BufferedWriter(tofile);
out.write(text.getText(),0,(text.getText()).length());
out.close();
tofile.close();
}
catch(IOException e2){}
}
}
}
}