Question

用JAVA编写记事本

（1）文件操作：新建、打开、保存、另存为、退出
（2）编辑：撤消、剪切、复制、粘贴、删除
（3）格式：自动换行
（4）帮助：关于
高级功能要求：
（1）为“新建” “打开” “保存” “撤消” “复制” “剪切” “粘贴”设置工具栏按钮
（2）编辑：查找、查找下一个、替换
（3）格式：字体设置、颜色的设置、时间显示
（4）添加状态栏，在状态栏显示当前文件是否已修改
基本功能要求：实现Window系统中“记事本”的基本功能。 请尽可能的简单,因为小弟我只学了2个月的JAVA!!谢谢 ...

Answer 1

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.InputEvent;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

import javax.swing.BorderFactory;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.KeyStroke;
import javax.swing.ScrollPaneConstants;
import javax.swing.SwingConstants;

public class JNotePadUI extends JFrame {
private JMenuItem menuOpen;
private JMenuItem menuSave;
private JMenuItem menuSaveAs;
private JMenuItem menuClose;

private JMenu editMenu;
private JMenuItem menuCut;
private JMenuItem menuCopy;
private JMenuItem menuPaste;

private JMenuItem menuAbout;

private JTextArea textArea;
private JLabel stateBar;
private JFileChooser fileChooser;

private JPopupMenu popUpMenu;

public JNotePadUI() {
super("新建文本文件");
setUpUIComponent();
setUpEventListener();
setVisible(true);
}

private void setUpUIComponent() {
setSize(640, 480);

// 菜单栏
JMenuBar menuBar = new JMenuBar();

// 设置「文件」菜单
JMenu fileMenu = new JMenu("文件");
menuOpen = new JMenuItem("打开");
// 快捷键设置
menuOpen.setAccelerator(
KeyStroke.getKeyStroke(
KeyEvent.VK_O,
InputEvent.CTRL_MASK));
menuSave = new JMenuItem("保存");
menuSave.setAccelerator(
KeyStroke.getKeyStroke(
KeyEvent.VK_S,
InputEvent.CTRL_MASK));
menuSaveAs = new JMenuItem("另存为");

menuClose = new JMenuItem("关闭");
menuClose.setAccelerator(
KeyStroke.getKeyStroke(
KeyEvent.VK_Q,
InputEvent.CTRL_MASK));

fileMenu.add(menuOpen);
fileMenu.addSeparator(); // 分隔线
fileMenu.add(menuSave);
fileMenu.add(menuSaveAs);
fileMenu.addSeparator(); // 分隔线
fileMenu.add(menuClose);

// 设置「编辑」菜单
JMenu editMenu = new JMenu("编辑");
menuCut = new JMenuItem("剪切");
menuCut.setAccelerator(
KeyStroke.getKeyStroke(KeyEvent.VK_X,
InputEvent.CTRL_MASK));
menuCopy = new JMenuItem("复制");
menuCopy.setAccelerator(
KeyStroke.getKeyStroke(KeyEvent.VK_C,
InputEvent.CTRL_MASK));
menuPaste = new JMenuItem("粘贴");
menuPaste.setAccelerator(
KeyStroke.getKeyStroke(KeyEvent.VK_V,
InputEvent.CTRL_MASK));
editMenu.add(menuCut);
editMenu.add(menuCopy);
editMenu.add(menuPaste);

// 设置「关于」菜单
JMenu aboutMenu = new JMenu("关于");
menuAbout = new JMenuItem("关于JNotePad");
aboutMenu.add(menuAbout);

menuBar.add(fileMenu);
menuBar.add(editMenu);
menuBar.add(aboutMenu);

setJMenuBar(menuBar);

// 文字编辑区域
textArea = new JTextArea();
textArea.setFont(new Font("宋体", Font.PLAIN, 16));
textArea.setLineWrap(true);
JScrollPane panel = new JScrollPane(textArea,
ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,
ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);

Container contentPane = getContentPane();
contentPane.add(panel, BorderLayout.CENTER);

// 状态栏
stateBar = new JLabel("未修改");
stateBar.setHorizontalAlignment(SwingConstants.LEFT);
stateBar.setBorder(
BorderFactory.createEtchedBorder());
contentPane.add(stateBar, BorderLayout.SOUTH);

popUpMenu = editMenu.getPopupMenu();
fileChooser = new JFileChooser();
}

private void setUpEventListener() {
// 按下窗口关闭钮事件处理
addWindowListener(
new WindowAdapter() {
public void windowClosing(WindowEvent e) {
closeFile();
}
}
);

// 菜单 - 打开
menuOpen.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
openFile();
}
}
);

// 菜单 - 保存
menuSave.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
saveFile();
}
}
);

// 菜单 - 另存为
menuSaveAs.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
saveFileAs();
}
}
);

// 菜单 - 关闭文件
menuClose.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
closeFile();
}
}
);

// 菜单 - 剪切
menuCut.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
cut();
}
}
);

// 菜单 - 复制
menuCopy.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
copy();
}
}
);

// 菜单 - 粘贴
menuPaste.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
paste();
}
}
);

// 菜单 - 关于
menuAbout.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
// 显示对话框
JOptionPane.showOptionDialog(null,
"程序名称:\n JNotePad \n" +
"程序设计:\n \n" +
"简介:\n 一个简单的文字编辑器\n" +
" 可作为验收Java的实现对象\n" +
" 欢迎网友下载研究交流\n\n" +
" /",
"关于JNotePad",
JOptionPane.DEFAULT_OPTION,
JOptionPane.INFORMATION_MESSAGE,
null, null, null);
}
}
);

// 编辑区键盘事件
textArea.addKeyListener(
new KeyAdapter() {
public void keyTyped(KeyEvent e) {
processTextArea();
}
}
);

// 编辑区鼠标事件
textArea.addMouseListener(
new MouseAdapter() {
public void mouseReleased(MouseEvent e) {
if(e.getButton() == MouseEvent.BUTTON3)
popUpMenu.show(editMenu, e.getX(), e.getY());
}

public void mouseClicked(MouseEvent e) {
if(e.getButton() == MouseEvent.BUTTON1)
popUpMenu.setVisible(false);
}
}
);
}

private void openFile() {
if(isCurrentFileSaved()) { // 文件是否为保存状态
open(); // 打开
}
else {
// 显示对话框
int option = JOptionPane.showConfirmDialog(
null, "文件已修改，是否保存？",
"保存文件？", JOptionPane.YES_NO_OPTION,
JOptionPane.WARNING_MESSAGE, null);
switch(option) {
// 确认文件保存
case JOptionPane.YES_OPTION:
saveFile(); // 保存文件
break;
// 放弃文件保存
case JOptionPane.NO_OPTION:
open();
break;
}
}
}
private boolean isCurrentFileSaved() {
if(stateBar.getText().equals("未修改")) {
return false;
}
else {
return true;
}
}
private void open() {
// fileChooser 是 JFileChooser 的实例
// 显示文件选取的对话框
int option = fileChooser.showDialog(null, null);

// 使用者按下确认键
if(option == JFileChooser.APPROVE_OPTION) {
try {
// 开启选取的文件
BufferedReader buf =
new BufferedReader(
new FileReader(
fileChooser.getSelectedFile()));

// 设定文件标题
setTitle(fileChooser.getSelectedFile().toString());
// 清除前一次文件
textArea.setText("");
// 设定状态栏
stateBar.setText("未修改");
// 取得系统相依的换行字符
String lineSeparator = System.getProperty("line.separator");
// 读取文件并附加至文字编辑区
String text;
while((text = buf.readLine()) != null) {
textArea.append(text);
textArea.append(lineSeparator);
}

buf.close();
}
catch(IOException e) {
JOptionPane.showMessageDialog(null, e.toString(),
"开启文件失败", JOptionPane.ERROR_MESSAGE);
}
}
}
private void saveFile() {
// 从标题栏取得文件名称
File file = new File(getTitle());

// 若指定的文件不存在
if(!file.exists()) {
// 执行另存为
saveFileAs();
}
else {
try {
// 开启指定的文件
BufferedWriter buf =
new BufferedWriter(
new FileWriter(file));
// 将文字编辑区的文字写入文件
buf.write(textArea.getText());
buf.close();
// 设定状态栏为未修改
stateBar.setText("未修改");
}
catch(IOException e) {
JOptionPane.showMessageDialog(null, e.toString(),
"写入文件失败", JOptionPane.ERROR_MESSAGE);
}
}
}

private void saveFileAs() {
// 显示文件对话框
int option = fileChooser.showSaveDialog(null);

// 如果确认选取文件
if(option == JFileChooser.APPROVE_OPTION) {
// 取得选择的文件
File file = fileChooser.getSelectedFile();

// 在标题栏上设定文件名称
setTitle(file.toString());

try {
// 建立文件
file.createNewFile();
// 进行文件保存
saveFile();
}
catch(IOException e) {
JOptionPane.showMessageDialog(null, e.toString(),
"无法建立新文件", JOptionPane.ERROR_MESSAGE);
}
}
}

private void closeFile() {
// 是否已保存文件
if(isCurrentFileSaved()) {
// 释放窗口资源，而后关闭程序
dispose();
}
else {
int option = JOptionPane.showConfirmDialog(
null, "文件已修改，是否保存？",
"保存文件？", JOptionPane.YES_NO_OPTION,
JOptionPane.WARNING_MESSAGE, null);

switch(option) {
case JOptionPane.YES_OPTION:
saveFile();
break;
case JOptionPane.NO_OPTION:
dispose();
}
}
}

private void cut() {
textArea.cut();
stateBar.setText("已修改");
popUpMenu.setVisible(false);
}

private void copy() {
textArea.copy();
popUpMenu.setVisible(false);
}

private void paste() {
textArea.paste();
stateBar.setText("已修改");
popUpMenu.setVisible(false);
}

private void processTextArea() {
stateBar.setText("已修改");
}

public static void main(String[] args) {
new JNotePadUI();
}
}

Answer 2

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

class MyMenuBar extends MenuBar{
public MyMenuBar(Frame parent){
parent.setMenuBar(this);
}
public void addMenus(String [] menus){
for(int i=0;i<menus.length;i++)
add(new Menu(menus[i]));
}
public void addMenuItems(int menuNumber,String[] items){
for(int i=0;i<items.length;i++){
if(items[i]!=null)
getMenu(menuNumber).add(new MenuItem(items[i]));
else getMenu(menuNumber).addSeparator();
}
}
public void addActionListener(ActionListener al){
for(int i=0;i<getMenuCount();i++)
for(int j=0;j<getMenu(i).getItemCount();j++)
getMenu(i).getItem(j).addActionListener(al);
}
}

class MyFile{
private FileDialog fDlg;
public MyFile(Frame parent){
fDlg=new FileDialog(parent,"",FileDialog.LOAD);
}
private String getPath(){
return fDlg.getDirectory()+"\\"+fDlg.getFile();
}
public String getData() throws IOException{
fDlg.setTitle("打开");
fDlg.setMode(FileDialog.LOAD);
fDlg.setVisible(true);
BufferedReader br=new BufferedReader(new FileReader(getPath()));
StringBuffer sb=new StringBuffer();
String aline;
while((aline=br.readLine())!=null)
sb.append(aline+'\n');
br.close();
return sb.toString();
}
public void setData(String data) throws IOException{
fDlg.setTitle("保存");
fDlg.setMode(FileDialog.SAVE);
fDlg.setVisible(true);
BufferedWriter bw=new BufferedWriter(new FileWriter(getPath()));
bw.write(data);
bw.close();
}
}

class MyClipboard{
private Clipboard cb;
public MyClipboard(){
cb=Toolkit.getDefaultToolkit().getSystemClipboard();
}
public void setData(String data){
cb.setContents(new StringSelection(data),null);
}
public String getData(){
Transferable content=cb.getContents(null);
try{
return (String) content.getTransferData(DataFlavor.stringFlavor);
//DataFlavor.stringFlavor会将剪贴板中的字符串转换成Unicode码形式的String对象。
//DataFlavor类是与存储在剪贴板上的数据的形式有关的类。
}catch(Exception ue){}
return null;
}
}

class MyFindDialog extends Dialog implements ActionListener{
private Label lFind=new Label("查找字符串");
private Label lReplace=new Label("替换字符串");
private TextField tFind=new TextField(10);
private TextField tReplace=new TextField(10);
private Button bFind=new Button("查找");
private Button bReplace=new Button("替换");
private TextArea ta;
public MyFindDialog(Frame owner,TextArea ta){
super(owner,"查找",false);
this.ta=ta;
setLayout(null);
lFind.setBounds(10,30,80,20);
lReplace.setBounds(10,70,80,20);
tFind.setBounds(90,30,90,20);
tReplace.setBounds(90,70,90,20);
bFind.setBounds(190,30,80,20);
bReplace.setBounds(190,70,80,20);
add(lFind);
add(tFind);
add(bFind);
add(lReplace);
add(tReplace);
add(bReplace);
setResizable(false);
bFind.addActionListener(this);
bReplace.addActionListener(this);
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
MyFindDialog.this.dispose();
}
});
}//构造函数结束
public void showFind(){
setTitle("查找");
setSize(280,60);
setVisible(true);
}
public void showReplace(){
setTitle("查找替换");
setSize(280,110);
setVisible(true);
}
private void find(){
String text=ta.getText();
String str=tFind.getText();
int end=text.length();
int len=str.length();
int start=ta.getSelectionEnd();
if(start==end) start=0;
for(;start<=end-len;start++){
if(text.substring(start,start+len).equals(str)){
ta.setSelectionStart(start);
ta.setSelectionEnd(start+len);
return;
}
}
//若找不到待查字符串，则将光标置于末尾
ta.setSelectionStart(end);
ta.setSelectionEnd(end);
}

public Button getBFind() {
return bFind;
}
private void replace(){
String str=tReplace.getText();
if(ta.getSelectedText().equals(tFind.getText()))
ta.replaceRange(str,ta.getSelectionStart(),ta.getSelectionEnd());
else find();
}

public void actionPerformed(ActionEvent e) {
if(e.getSource()==bFind)
find();
else if(e.getSource()==bReplace)
replace();
}
}

public class MyMemo extends Frame implements ActionListener{
private TextArea editor=new TextArea(); //可编辑的TextArea
private MyFile mf=new MyFile(this);//MyFile对象
private MyClipboard cb=new MyClipboard();
private MyFindDialog findDlg=new MyFindDialog(this,editor);

public MyMemo(String title){ //构造函数
super(title);
MyMenuBar mb=new MyMenuBar(this);
//添加需要的菜单及菜单项
mb.addMenus(new String[]{"文件","编辑","查找","帮助"});
mb.addMenuItems(0,new String[]{"新建","打开","保存",null,"全选"});
mb.addMenuItems(1,new String[]{"剪贴","复制","粘贴","清除",null,"全选"});
mb.addMenuItems(2,new String[]{"查找",null,"查找替换"});
mb.addMenuItems(3,new String[]{"我的记事本信息"});

add(editor); //为菜单项注册动作时间监听器
mb.addActionListener(this);

addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
MyMemo.this.dispose();
}
}); //分号不能忘了
} //构造函数完

public void actionPerformed(ActionEvent e){
String selected=e.getActionCommand(); //获取菜单项标题
if(selected.equals("新建"))
editor.setText("");
else if(selected.equals("打开")){
try{
editor.setText(mf.getData());
}catch(IOException ie){}
}
else if(selected.equals("保存")){
try{
mf.setData(editor.getText());
}catch(IOException ie){}
}
else if(selected.equals("退出")){
dispose();
}
else if(selected.equals("剪贴")){
//将选中的字符串复制到剪贴板中并清除字符串
cb.setData(editor.getSelectedText());
editor.replaceRange("",editor.getSelectionStart(),editor.getSelectionEnd());
}
else if(selected.equals("复制")){
cb.setData(editor.getSelectedText());
}
else if(selected.equals("粘贴")){
String str=cb.getData();
editor.replaceRange(str,editor.getSelectionStart(),editor.getSelectionEnd());
//粘贴在光标位置
}
else if(selected.equals("清除")){
editor.replaceRange("",editor.getSelectionStart(),editor.getSelectionEnd());
}
else if(selected.equals("全选")){
editor.setSelectionStart(0);
editor.setSelectionEnd(editor.getText().length());
}
else if(selected.equals("查找")){
findDlg.showFind();
}
else if(selected.equals("查找替换")){
findDlg.showReplace();
}
}

public static void main(String[] args){
MyMemo memo=new MyMemo("记事本");
memo.setSize(300,300);
memo.setVisible(true);
}
}

Answer 3

主要就是事件处理机制了
你完全可以自己做
事件处理中不会的地方可以找我一起研究
swing做出一个GUI的框架
然后给菜单项做事件监听

Answer 4

java安装目录下有个demo文件夹，里面有个现成的例子。
C:\Program Files\Java\jdk1.6.0_06\demo\jfc\notepad

Answer 5

我有怎么给你啊，要的话请联系我QQ：504833534