可扩展的基本记事本

import java.awt.BorderLayout;import java.awt.Color;import java.awt.FlowLayout;import java.awt.datatransfer.Clipboard;import java.awt.datatransfer.DataFlavor;import java.awt.datatransfer.Transferable;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.FocusEvent;import java.awt.event.FocusListener;import java.awt.event.InputEvent;import java.awt.event.MouseEvent;import java.awt.event.MouseListener;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.File;import java.io.FileNotFoundException;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import javax.swing.JFileChooser;import javax.swing.JFrame;import javax.swing.JMenu;import javax.swing.JMenuBar;import javax.swing.JMenuItem;import javax.swing.JOptionPane;import javax.swing.JPanel;import javax.swing.JPopupMenu;import javax.swing.JScrollPane;import javax.swing.JTextArea;import javax.swing.KeyStroke;import javax.swing.filechooser.FileFilter;public class Demo extends JFrame {private static final long serialVersionUID = 1L; //Eclipse×Ô¶¯Éú³ÉÐòÁкÅString name = "ÎÞ±êÌâ";JPanel menuPanel = new JPanel();JTextArea text = new TextAreaMenu(); //Îı¾±à¼-ÇøJScrollPane jsp = new JScrollPane(text); //¿É¹ö¶¯±à¼-ÇøJMenuBar mnbMain = new JMenuBar();JMenu mnServer = new JMenu("Îļþ(F)");JMenu mnEdit = new JMenu("±à¼-(E)");JMenuItem[] mniServers = new JMenuItem[]{new JMenuItem("н¨(N)"),new JMenuItem("±£´æ(S)"),new JMenuItem("´ò¿ª(O)"),new JMenuItem("Í˳ö(X)"),};{menuPanel.setLayout(new FlowLayout(FlowLayout.LEFT, 0, 0));mnbMain.add(mnServer);menuPanel.add(mnbMain);mnbMain.setBounds(5, 0, 50, 30);for (int i = 0; i < mniServers.length; i++) {mnServer.add(mniServers[i]);}mniServers[0].addActionListener(new ActionListener() { //¶¨Òå"н¨"×é¼þ²Ù×÷@Overridepublic void actionPerformed(ActionEvent arg0) {new Demo(getLocation().x+15,getLocation().y+5);}});mniServers[1].addActionListener(new ActionListener() { //¶¨Òå"±£´æ"×é¼þ²Ù×÷@Overridepublic void actionPerformed(ActionEvent arg0) {chooseToSave();}});mniServers[2].addActionListener(new ActionListener() { //¶¨Òå"´ò¿ª"×é¼þ²Ù×÷@Overridepublic void actionPerformed(ActionEvent arg0) {chooseToOpen();}});mniServers[3].addActionListener(new ActionListener() { //¶¨Òå"Í˳ö"×é¼þ²Ù×÷@Overridepublic void actionPerformed(ActionEvent arg0) {System.exit(0);}});text.addFocusListener(new FocusListener() {@Overridepublic void focusLost(FocusEvent e) {// TODO Auto-generated method stub}@Overridepublic void focusGained(FocusEvent e) {}});}public Demo(int x,int y) {this.setTitle( name +" - ¼Çʱ¾");this.setBounds(x, y, 600, 400);this.setLayout(new BorderLayout());this.add(menuPanel, BorderLayout.NORTH);this.add(jsp);jsp.setBounds(5, 30, getWidth()-10, getHeight()-50);this.setDefaultCloseOperation(DISPOSE_ON_CLOSE);this.setVisible(true);}public Demo() {this(200,200);}protected void chooseToSave() {File file = chooseFile();if(null==file)return;if(file.exists()){int cho = JOptionPane.showConfirmDialog(this, "ÎļþÒÑ´æÔÚ£¬ÊÇ·ñ¸²¸Ç£¿");System.out.println(cho);if(cho==JOptionPane.OK_OPTION)save(file);else return;}else save(file);}private void save(File file) {name = file.getName();write(text.getText(),file.getPath());this.setTitle( name +" - ¼Çʱ¾");}protected void chooseToOpen() {File file = chooseFile();if(null==file||!file.exists())return;name = file.getName();Demo.this.setTitle( name +" - ¼Çʱ¾");read(text,file);}/*********************************************MAIN**************** **********************************/public static void main(String[] args) {new Demo();}private File chooseFile(){JFileChooser chooser = new JFileChooser(); //¹¹½¨ÎļþÑ¡ÔñÆ÷chooser.setFileFilter(new FileFilter() {@Overridepublic String getDescription() {return "Îı¾Îļþ";}@Overridepublic boolean accept(File f) {String name = f.getName().toLowerCase();return f.isDirectory() || name.endsWith(".txt")||name.endsWith(".c") || name.endsWith(".java")||name.endsWith(".cpp"); //¿Éʶ±ðÎļþ}});int result = chooser.showDialog(null, "È·¶¨");if (result==JFileChooser.APPROVE_OPTION) {File file = chooser.getSelectedFile();System.out.println(file.getAbsolutePath());} else {System.out.println("δѡÔñÎļþ");}return chooser.getSelectedFile();}public static void read(JTextArea text,File file){ //¶¨Òå¶ÁÈ¡Îļþ²Ù×÷FileReader fr;try {fr = new FileReader(file);BufferedReader br = new BufferedReader(fr);String string = null;while((string = br.readLine()) != null){text.append(string+"\n");}br.close();fr.close();} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}public static void write(String txt,String fileName){FileWriter fw;try {fw = new FileWriter(fileName);BufferedWriter bw = new BufferedWriter(fw);bw.write(txt);bw.flush();bw.close();fw.close();} catch (IOException e) {e.printStackTrace();}}}class TextAreaMenu extends JTextArea implements MouseListener {private static final long serialVersionUID = -2308615404205560110L;private JPopupMenu pop = null; // µ¯³ö²Ëµ¥private JMenuItem selectAll = null,copy = null, paste = null, cut = null, cancel=null; // ¹¦Äܲ˵¥public TextAreaMenu() {super();init();}private void init() {this.addMouseListener(this);this.setSelectedTextColor(Color.red);pop = new JPopupMenu();pop.add(selectAll = new JMenuItem("È«Ñ¡"));pop.add(copy = new JMenuItem("¸´ÖÆ"));pop.add(paste = new JMenuItem("Õ³Ìù"));pop.add(cut = new JMenuItem("¼ôÇÐ"));pop.add(cancel = new JMenuItem("³·Ïú"));selectAll.setAccelerator(KeyStroke.getKeyStroke('A',InputEvent.CTRL_MASK));copy.setAccelerator(KeyStroke.getKeyStroke('C',InputEvent.CTRL_MASK));paste.setAccelerator(KeyStroke.getKeyStroke('V',InputEvent.CTRL_MASK));cut.setAccelerator(KeyStroke.getKeyStroke('X',InputEvent.CTRL_MASK));cancel.setAccelerator(KeyStroke.getKeyStroke('Z',InputEvent.CTRL_MASK));copy.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {action(e);}});paste.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {action(e);}});cut.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {action(e);}});this.add(pop);}/*** ²Ëµ¥¶¯×÷* @param e*/public void action(ActionEvent e) {String str = e.getActionCommand();if (str.equals(selectAll.getText())) { // È«Ñ¡this.selectAll();}else if (str.equals(copy.getText())) { // ¸´ÖÆthis.copy();} else if (str.equals(paste.getText())) { // Õ³Ìù this.paste();} else if (str.equals(cut.getText())) { // ¼ôÇÐthis.cut();}else if (str.equals(cancel.getText())) { //³·Ïúthis.cut();}}public JPopupMenu getPop() {return pop;}public void setPop(JPopupMenu pop) {this.pop = pop;}/*** ¼ôÇаåÖÐÊÇ·ñÓÐÎı¾Êý¾Ý¿É¹©Õ³Ìù** @return trueΪÓÐÎı¾Êý¾Ý*/public boolean isClipboardString() {boolean b = false;Clipboard clipboard = this.getToolkit().getSystemClipboard();Transferable content = clipboard.getContents(this);try {if (content.getTransferData(DataFlavor.stringFlavor) instanceof String) {b = true;}} catch (Exception e) {}return b;}/*** Îı¾×é¼þÖÐÊÇ·ñ¾ß±¸¸´ÖƵÄÌõ¼þ** @return trueΪ¾ß±¸*/public boolean isCanCopy() {boolean b = false;int start = this.getSelectionStart();int end = this.getSelectionEnd();if (start != end)b = true;return b;}public void mouseClicked(MouseEvent e) {}public void mouseEntered(MouseEvent e) {}public void mouseExited(MouseEvent e) {}public void mousePressed(MouseEvent e) {if (e.getButton() == MouseEvent.BUTTON3) { copy.setEnabled(isCanCopy());paste.setEnabled(isClipboardString());cut.setEnabled(isCanCopy());pop.show(this, e.getX(), e.getY());}}public void mouseReleased(MouseEvent e) { }}。