e1308.java

java小程序

import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class E1308 extends JFrame implements ActionListener
{
private JMenuBar bar=new JMenuBar();
private Container c;
private JMenu menu=new JMenu("File");
private JMenuItem item1=new JMenuItem("open");
private JMenuItem item2=new JMenuItem("Save As...");
private JLabel label=new JLabel("Open及Save As... 测试");
FileDialog filedialog_save=new FileDialog(this,"保存文件对话框",FileDialog.SAVE);
FileDialog filedialog_load=new FileDialog(this,"打开文件对话框",FileDialog.LOAD);
TextArea text=new TextArea("",12,20);//有滚动条，JTextArea没有！
BufferedReader in;
FileReader file_reader;
BufferedWriter out;
FileWriter tofile;

public E1308()
{
super("E1308.java:JMenuItem测试");
c=getContentPane();
menu.add(item1);
menu.add(item2);
bar.add(menu);
setJMenuBar(bar);
label.setFont(new Font("Serif",Font.PLAIN,20));
c.add(label);
c.add(text,BorderLayout.SOUTH);
item1.addActionListener(this);
item2.addActionListener(this);
setSize(600,300);
setVisible(true);
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);
}
}
);
}

public void actionPerformed(ActionEvent e)
{
if(e.getSource()==item1)
{
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()==item2)
{
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){}
}
}
}
    
public static void main(String args[])
{
E1308 app=new E1308();
app.addWindowListener(new MyWindowListener());
}
}