JAVA程序设计题： 文本编辑器设计

JAVA程序设计题：文本编辑器设计

【问题描述】

实现类似Windows操作系统“记事本”的功能。它是一个简单的文本文档编辑器，可以创建、查看或编辑文本文件。

【实验目的】

要求学生能熟练使用基于Swing的GUI设计，熟练使用常用组件和容器，理解java事件处理机制，会查看API documentation完成设计任务，熟练文件流的操作。

【基本功能】

设计一个文本编辑器，通过菜单组件可以创建、查看或编辑文本文件。

增加对文件的存贮、剪切和黏贴等功能

功能的其他扩展

package com.huangyilun.work;

import java.awt.*;

import java.awt.event.*;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileWriter;

import javax.swing.*;

public class Notice_B08010332 extends JFrame {

public static void main(String[] args) {

new Notice_B08010332();

}

public Notice_B08010332() {

super("新建文本文件");

setUpUIComponent();

setUpEventListener();

setVisible(true);

this.showForm();

}

private void showForm(){

//侦听窗口关闭操作

setDefaultCloseOperation( JFrame.DO_NOTHING_ON_CLOSE);

addWindowListener(new WindowAdapter() {

public void windowClosing(WindowEvent e) {

dispose();

System.exit(0);

}

});

}

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);

menuBar.add(fileMenu);

menuBar.add(editMenu);

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();

}

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();

}

});

// 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 true;

} else {

return false;

}

}

private void open() {

JFileChooser chooser = new JFileChooser();

chooser.showOpenDialog(this);

File file = chooser.getSelectedFile();

currFile = file;

String str = "";

try{

FileInputStream fileinput = new FileInputStream(file.getAbsolutePath());

int x = fileinput.available();

byte b[] = new byte[x];

fileinput.read(b);

str = new String(b);

}catch(Exception e){

e.printStackTrace();

}

if (file != null)

this.textArea.setText(str);

}

private void saveFile() {

String str = this.textArea.getText();

if(currFile != null && !currFile.equals("")){

try{

FileWriter out = new FileWriter(currFile);

out.write(str);

out.close();

}catch(Exception e){

e.printStackTrace();

}

}else{

saveFileAs();

}

stateBar.setText("已保存");

}

private void saveFileAs() {

JFileChooser chooser = new JFileChooser();

chooser.showOpenDialog(this);

File file = chooser.getSelectedFile();

currFile = file;

String str = this.textArea.getText();

if(currFile != null && !currFile.equals("")){

try{

FileWriter out = new FileWriter(currFile);

out.write(str);

out.close();

}catch(Exception e){

e.printStackTrace();

}

}

stateBar.setText("已保存");

}

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");

}

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 JTextArea textArea;

private JLabel stateBar;

private JPopupMenu popUpMenu;

private File currFile;

}