jar包的问题！ - 黑马程序员技术交流社区

/*
书写一个打开与保存
思路：
1.确定主题
2.构造方法
步骤：
1.主题 Frame FileDialog MenuBar Menu MenuItem
2.构造方法
*/
import java.awt.*;
import java.awt.event.*;
import java.io.*;
class MyMenuTest
{
private Frame f;
private TextArea ta;
private MenuBar mb;
private Menu m;
private MenuItem closeItem,saveItem,loadItem;
private FileDialog save,load;
private File file;
MyMenuTest()
{
init();
}
public void init()
{
f = new Frame("文本");
ta = new TextArea();
mb = new MenuBar();
m = new Menu("菜单");
loadItem = new MenuItem("打开");
saveItem = new MenuItem("保存");
closeItem = new MenuItem("退出");
load = new FileDialog(f,"打开");
save = new FileDialog(f,"保存",FileDialog.SAVE);
f.setMenuBar(mb);
f.add(ta);
mb.add(m);
m.add(loadItem);
m.add(saveItem);
m.add(closeItem);
f.setBounds(400,50,600,600);
监听();
f.setVisible(true);
}
private void 监听()
{
saveItem.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
if(file == null)
{
save.setVisible(true);
String dir = save.getDirectory();
String name = save.getFile();
if(dir == null && name == null)
return ;
file = new File(dir,name);
}
try
{
PrintWriter pw = new PrintWriter(new FileWriter(file),true);
pw.println(ta.getText());
pw.close();
}
catch (Exception ex)
{
}
}
});
loadItem.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
load.setVisible(true);
ta.setText("");
String dir = load.getDirectory();
String name = load.getFile();
try
{
file = new File(dir,name);
BufferedReader br = new BufferedReader(new FileReader(file));
String line = null;
while ((line = br.readLine()) != null)
{
ta.append(line+"\r\n");
}
br.close();
}
catch (Exception ex)
{
}
}
});
f.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
closeItem.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
});
}
public static void main(String[] args)
{
new MyMenuTest();
}
}

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