mynotepad.java

一般记事本的功能

package notepad;

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;
import javax.swing.event.*;

import java.io.*;

public class MyNotepad extends WindowAdapter implements ActionListener,DocumentListener{
	private JFrame    frame;
	private JMenuBar  menuBar;
	private JMenu     menus[];
	private JMenuItem items[][];
	
	//private final int itemCount;
	private JTextArea   text;
	private JScrollPane text_scroll;
	
	private String content;
	private boolean content_changed;
	
	private final String menuName[] = {"文件", "编辑", "视图", "帮助"};
	private final String menuItemName[][] = {   //所有菜单项  分别对应
			{"新建",   "打开",   "保存", "另存为...","退出"},  //--文件
			{"查找...","替换...","复制", "剪切",     "粘贴"},  //--编辑
			{"字体...","颜色..."},                          //--视图
			{"帮助",   "关于"}                              //--帮助
		};
	
	//该程序使用到的私有方法
	private void initMenu() {
		int menuNum = menuName.length;
		menus = new JMenu[menuNum];
		for (int i=0; i<menuNum; ++i) {
			menus[i] = new JMenu(menuName[i]);
		}
	}
	
	private void initMenuItem() {
		int menuItemNum = menuItemName.length;
		items = new JMenuItem[menuItemNum][];
		
		for (int i=0; i<menuItemNum; ++i) {
			int count = menuItemName[i].length;
			items[i] = new JMenuItem[count];
			
			for (int j=0; j<count; ++j) {
				items[i][j] = new JMenuItem(menuItemName[i][j]);
			}
		}
	}//end of initMenuItem
	
	private void addMenu() {
		for (int i=0; i<menus.length; ++i){
			menuBar.add(menus[i]);
		}
	}
	
	private void addMenuItem() {
		for (int i=0; i<menus.length; ++i){
			for (int j=0; j<items[i].length; ++j) {
				menus[i].add(items[i][j]);
			}
		}
	}
	
	private void addActionListenerForMenuItem() {
		int the_c = 0;
		for (int i=0; i<items.length; ++i){
			the_c = items[i].length;
			
			for (int j=0; j<the_c; ++j) {
				items[i][j].addActionListener(this);
			}
		}
	}
	
	//构造函数
	public MyNotepad() {
		super();

		content = "";
		content_changed = false;
		
		frame = new JFrame();
		menuBar = new JMenuBar();
		text = new JTextArea();
		text_scroll = new JScrollPane(text);
		
		initMenu();
		initMenuItem();
		frame.setTitle("俺的记事本...");
		
		addMenu();
		addMenuItem();
		
		addActionListenerForMenuItem();
		text.getDocument().addDocumentListener(this);
		frame.addWindowListener(this);
		
		frame.add(menuBar, BorderLayout.NORTH);
		frame.add(text_scroll, BorderLayout.CENTER);
		
		frame.setVisible(true);
		frame.setSize(600, 460);
		frame.setLocation(220, 180);
		frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);


//		setMenuBar(menuBar);
	}

	public void actionPerformed(ActionEvent e) {
		String str = e.getActionCommand();
		
		// 文件菜单事件
		if ("新建".equals(str)) {
			/*
			fileDlg = new FileDialog(this, "请选择一个文件", FileDialog.LOAD);
			fileDlg.setVisible(true);
			String file = fileDlg.getFile();
			String path = fileDlg.getDirectory();

			File f = new File(path + file);
			int length = (int) f.length();
			char buffer[] = new char[length];

			if (null != file) {

				try {
					FileReader fReader = new FileReader(f);
					fReader.read(buffer);
				} catch (FileNotFoundException e1) {
					// TODO Auto-generated catch block
					e1.printStackTrace();
				} catch (IOException e1) {
					// TODO Auto-generated catch block
					e1.printStackTrace();
				}

			}
			content = new String(buffer);
			text.setText(content);
			*/
		}
		if ("打开".equals(str)) {
			openFile();
		}
		if ("保存".equals(str)) {
			saveFile();
		}
		if ("另存为...".equals(str)) {
			saveFile();
		}
		if ("退出".equals(str)) {
			exitNotepad();
		}
		
		
		// 编辑菜单事件 
		if ("查找...".equals(str)) {
			find();
		}
		if ("替换...".equals(str)) {
			replace();
		}
		if ("复制".equals(str)) {
		}
		if ("剪切".equals(str)) {
		}
		if ("粘贴".equals(str)) {
		}
		
		// 视图菜单事件
		if ("字体...".equals(str)) {
			chooseFont();
		}
		if ("颜色...".equals(str)) {
			chooseColor();
		}
		
		// 帮助菜单事件
		if ("帮助".equals(str)) {
		}
		if ("关于".equals(str)) {
			about();
		}
	}// end of actionPerformed
	
	//监听文本改变事件
	public void changedUpdate(DocumentEvent e) {
		content_changed = true;
	}

	public void insertUpdate(DocumentEvent e) {
		content_changed = true;
	}

	public void removeUpdate(DocumentEvent e) {
		content_changed = true;
	}

	private void openFile() {
		JFileChooser fileCh= new JFileChooser();
		int result = fileCh.showOpenDialog(frame);
		
		if (result != JFileChooser.APPROVE_OPTION) {
			return;
		}
		
		File file = fileCh.getSelectedFile();
		System.out.print(file);
		
		FileReader fr = null;
		BufferedReader br = null;
		
		try {
			fr = new FileReader(file);
			int in = 0;
			while ((in = fr.read()) != -1) {
				content += (char)in;
			}
			fr.close();
		}
		catch (IOException ioe) {
			ioe.printStackTrace();
		}
		text.setText(content);
	}
	
	private void saveFile() {
		JFileChooser fileCh= new JFileChooser();
		int result = fileCh.showSaveDialog(frame);
		
		if (result != JFileChooser.APPROVE_OPTION) {
			return;
		}
		
		File file = fileCh.getSelectedFile();
		System.out.print(file);
		
		FileWriter fos = null;
		BufferedWriter bos = null;
		
		try {
			fos = new FileWriter(file);
			bos = new BufferedWriter(fos);
			
			bos.write(content, 0, content.length());
			
			fos.flush();
			bos.flush();
			
			fos.close();
			bos.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	private void find() {
		String result = JOptionPane.showInputDialog(frame,
				"请输入你要查找的内容", "查找", JOptionPane.INFORMATION_MESSAGE);
	}
	private void replace() {
		JOptionPane.showMessageDialog(frame,
				"该功能暂时还未实现", "替换", JOptionPane.INFORMATION_MESSAGE);
	}
	
	private void chooseFont() {
		MyFontDlg fontDlg = new MyFontDlg(frame, "选择字体对话框", true);
		//fontDlg.setFontDlgSize(360,260);
		text.setFont(fontDlg.getFont());
		//System.out.println(fontDlg.getFont().hashCode());
	}
	
	private void chooseColor() {
		Color color = JColorChooser.showDialog(frame, "choose color", Color.BLACK);
		text.setForeground(color);
	}
	
	private void about() {
		JOptionPane.showMessageDialog(frame,
				"该程序由hehe独立编写\n在使用过程中如果遇到什么问题，请与我联系:\[e-mail]", 
				"关于", JOptionPane.INFORMATION_MESSAGE);
	}
	
	// 重写WindowAdapter类的方法
	public void windowClosing(WindowEvent we) {
		if (!content_changed) {
			int res = JOptionPane.showConfirmDialog(frame, "真的要退出吗？", "确认退出",
					JOptionPane.YES_NO_OPTION);
			if (res == JOptionPane.YES_OPTION) {
				System.exit(0);
			}
		}
		else if (chooseSaveFile()) {  //要保存文件
			saveFile();
			content_changed = false;
		}
		else {
			System.exit(0);
		}
	}

	public void exitNotepad() {
		if (!content_changed) {  //内容没有改变， 直接退出
			System.exit(0);
			return;
		}
		else if (chooseSaveFile()) {  //要保存文件
			saveFile();
			content_changed = false;
		}
		else {
			System.exit(0);
		}
	}
	
	private boolean chooseSaveFile(){
		boolean result = false;
		int res = JOptionPane.showConfirmDialog(frame, 
				"当前的文件内容已经改变，\n请确认保存文件！", "保存更改", JOptionPane.YES_NO_CANCEL_OPTION);
		if (res == JOptionPane.YES_OPTION) {
			result = true;
		}
		return result;
	}
	
	public static void main(String[] args) {
		new MyNotepad();
	}
}