一个简易的记事本

来源：互联网发布：美国大发战争财数据编辑：程序博客网时间：2024/04/29 14:50

可以通过菜单选项打开文本文件，可以编辑，保存文件

packagemymenu;

importjava.awt.*;

importjava.awt.event.*;

importjava.io.*;

classMenuDemo2{

private Frame f = new Frame();

private MenuBar mbar = new MenuBar();

private Menu fileMenu = new Menu("文件");

private FileDialog openDialog = newFileDialog(f,"打开文件",FileDialog.LOAD);

private FileDialog saveDialog = newFileDialog(f,"保存文件",FileDialog.SAVE);

private MenuItem openItem = newMenuItem("打开");

private MenuItem saveItem = newMenuItem("保存");

private MenuItem closeItem = newMenuItem("关闭");

private TextArea textArea = newTextArea(30,30);

private File file = null;

MenuDemo2(){

init();

event();

}

public void init(){

f.setBounds(100,100,500,400);

fileMenu.add(openItem);

fileMenu.add(saveItem);

fileMenu.add(closeItem);

mbar.add(fileMenu);

f.setMenuBar(mbar);

f.setVisible(true);

f.add(textArea);

//f.pack();

}

public void event(){

f.addWindowListener(newWindowAdapter(){

public voidwindowClosing(WindowEvent e){

System.exit(0);

}

});

//在关闭条目上添加一个监听器，如果点击则退出

closeItem.addActionListener(newActionListener(){

public voidactionPerformed(ActionEvent e){

System.exit(0);

}

});

//保存文件

saveItem.addActionListener(newActionListener(){

public voidactionPerformed(ActionEvent e){

if(file ==null)

saveDialog.setVisible(true);

StringfilePath = saveDialog.getDirectory();

StringfileName = saveDialog.getFile();

if(filePath== null || fileName == null)

return;

BufferedWriterbw = null;

file = newFile(filePath,fileName );

try{

bw =new BufferedWriter(new FileWriter(file));

Stringstr = textArea.getText();

bw.write(str);

bw.flush();

}catch(IOExceptionex){

thrownew RuntimeException("文件保存失败");

}finally{

if(bw!= null){

try{

bw.close();

}catch(IOExceptionex){

throw new RuntimeException("输入流关闭失败");

}

});

//打开文件

openItem.addActionListener(newActionListener(){

public voidactionPerformed(ActionEvent e){

openDialog.setVisible(true);

StringfilePath = openDialog.getDirectory();

StringfileName = openDialog.getFile();

if(filePath== null || fileName == null)

return;

textArea.setText("");

file = newFile(filePath,fileName );

BufferedReaderbr = null;

try{

br = new BufferedReader(newFileReader(file));

Stringstr = null;

while((str= br.readLine()) != null){

textArea.append(str+ "\r\n");

}

}catch(IOExceptionex){

thrownew RuntimeException("文件打开失败");

}finally{

if(br!= null){

try{

br.close();

}catch(IOExceptionex){

throw new RuntimeException("输出流关闭失败");

}

});

}

public static void main(String[] args){

new MenuDemo2();

}