Java完整实现记事本代码

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.GraphicsEnvironment;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JColorChooser;
import javax.swing.JComboBox;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.jscrollPane;
import javax.swing.JTextArea;
import javax.swing.JToolBar;
import javax.swing.filechooser.FileNameExtensionFilter;
import chenhao.io.TextTool;
public class TextPad {
	private JTextArea contentArea;
	private JFrame frame;
	private String fileName;
	public TextPad() {
		frame = new JFrame("记事本");
		frame.setSize(500, 500);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		// 添加菜單
		JMenuBar menuBar = new JMenuBar();
		JMenu menu = new JMenu("文件");
		JMenuItem newItem = new JMenuItem("新建");
		newAction(newItem);
		menu.add(newItem);
		JMenuItem openItem = new JMenuItem("打开");
		openAction(openItem);
		menu.add(openItem);
		JMenuItem saveItem = new JMenuItem("保存");
		saveAction(saveItem);
		menu.add(saveItem);
		menuBar.add(menu);
		frame.setJMenuBar(menuBar);
		// 布局
		frame.setLayout(new BorderLayout());
		JToolBar toolBar = new JToolBar();
		JComboBox<String> fontCom = fontAction();
		toolBar.add(fontCom);
		JComboBox<String> fontSize = fontSizeAction();
		toolBar.add(fontSize);
		fontStyleAction(toolBar);
		JButton colorbtn = fontColorAction();
		toolBar.add(colorbtn);
		frame.add(toolBar, BorderLayout.NORTH);
		// 文件编辑区
		contentArea = new JTextArea();
		JScrollPane pane = new JScrollPane(contentArea);
		frame.add(pane);
		frame.setVisible(true);
	}
	private JButton fontColorAction() {
		JButton colorbtn = new JButton("■");
		colorbtn.addActionListener(new ActionListener() {
			@Override
			public void actionPerfORMed(ActionEvent e) {
				Color color = colorbtn.getForeground();
				Color co = JColorChooser.showDialog(TextPad.this.frame, "设置字体颜色", color);
                 colorbtn.setForeground(co);
                 contentArea.setForeground(co);
			}
		});
		return colorbtn;
	}
	// 记事本，字体格式
	private void fontStyleAction(JToolBar toolBar) {
		JCheckBox boldBox = new JCheckBox("粗体");
		JCheckBox itBox = new JCheckBox("斜体");
		ActionListener actionListener = new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				boolean bold = boldBox.isSelected();
				boolean it = itBox.isSelected();
				int style = (bold ? Font.BOLD : Font.PLaiN) | (it ? Font.ITALIC : Font.PLAIN);
				Font font = contentArea.getFont();
				contentArea.setFont(new Font(font.getName(), style, font.getSize()));
				//contentArea.setFont(new Font(font.getName(), style, font.getSize()));
			}
		};
		boldBox.addActionListener(actionListener);
		itBox.addActionListener(actionListener);
		toolBar.add(boldBox);
		toolBar.add(itBox);
	}
	// 记事本，设置字体大小
	private JComboBox<String> fontSizeAction() {
		String[] fontSizes = new String[] { "10", "20", "30", "50" };
		JComboBox<String> fontSize = new JComboBox<>(fontSizes);
		fontSize.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				int size = Integer.valueOf((String) fontSize.getSelectedItem());
				Font font = TextPad.this.contentArea.getFont();
				TextPad.this.contentArea.setFont(new Font(font.getName(), font.getStyle(), size));
			}
		});
		return fontSize;
	}
	// 记事本，设置字体
	private JComboBox<String> fontAction() {
		GraphicsEnvironment environment = GraphicsEnvironment.getLocalGraphicsEnvironment();
		String[] fontNames = environment.getAvailableFontFamilyNames();
		JComboBox<String> fontCom = new JComboBox<>(fontNames);
		fontCom.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				String fontName = (String) fontCom.getSelectedItem();
				Font font = TextPad.this.contentArea.getFont();
				TextPad.this.contentArea.setFont(new Font(fontName, font.getStyle(), font.getSize()));
			}
		});
		return fontCom;
	}
	// 记事本新建操作
	private void newAction(JMenuItem newItem) {
		newItem.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				contentArea.setText("");
				frame.setTitle("新建-记事本");
				fileName = null;
			}
		});
	}
	// 记事本打开文件操作
	private void openAction(JMenuItem openItem) {
		openItem.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				JFileChooser chooser = new JFileChooser();
				FileNameExtensionFilter filter = new FileNameExtensionFilter("Text & dat", "txt", "dat");
				chooser.setFileFilter(filter);
				int returnVal = chooser.showOpenDialog(frame);
				if (returnVal == JFileChooser.APPROVE_OPTION) {
					String fileName = chooser.getSelectedFile().getPath();
					TextPad.this.fileName = fileName;
					String content = TextTool.read(fileName);
					contentArea.setText(content);
					TextPad.this.frame.setTitle(fileName + "- 记事本");
				}
			}
		});
	}
	// 菜单 保存操作
	private void saveAction(JMenuItem saveItem) {
		saveItem.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				if (TextPad.this.fileName != null) {
					String content = TextPad.this.contentArea.getText();
					TextTool.write(TextPad.this.fileName, content);
				} else {
					JFileChooser chooser = new JFileChooser();
					FileNameExtensionFilter filter = new FileNameExtensionFilter("Text & dat", "txt", "dat");
					chooser.setFileFilter(filter);
					int returnVal = chooser.showSaveDialog(frame);
					if (returnVal == JFileChooser.APPROVE_OPTION) {
						String fileName = chooser.getSelectedFile().getPath();
						TextPad.this.fileName = fileName;
						String content = TextPad.this.contentArea.getText();
						TextTool.write(TextPad.this.fileName, content);
						TextPad.this.frame.setTitle(fileName + "- 记事本");
					}
				}
			}
		});
	}
	public static void main(String[] args) {
		TextPad pad = new TextPad();
	}
}

import java.awt.image.BufferedImage;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Reader;
import java.io.Writer;
import javax.swing.JOptionPane;
public class TextTool {
	public static String read(String fileName) {
		try (Reader reader = new FileReader(fileName); BufferedReader buff = new BufferedReader(reader);) {
			String str;
			StringBuilder sb = new StringBuilder();
			while ((str = buff.readLine()) != null) {
				str = decoding(str);
				sb.append(str + "\n");
			}

			return sb.toString();
		} catch (FileNotFoundException e) {
			JOptionPane.showMessageDialog(null, "找不到文件路径" + fileName);
		} catch (IOException e) {
			e.printStackTrace();
		}
		return null;
	}
	public static void write(String fileName, String content) {

		try (Writer writer = new FileWriter(fileName);) {
			content = encoding(content);
			writer.write(content);
			writer.flush();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	public static String encoding(String str) {
		String temp = "";
		for (int i = 0; i < str.length(); i++) {
			if(str.charAt(i)=='\n')
			{
				temp+=str.charAt(i);
			}
			else if (0 <= str.charAt(i) && str.charAt(i) <= 255)
				temp += (char) ((str.charAt(i) - '0' + 10) % 255);
			else
				temp += str.charAt(i);
		}
		return temp;
	}
	public static String decoding(String str) {
		String temp = "";
		for (int i = 0; i < str.length(); i++) {
			if(str.charAt(i)=='\n')
			{
				temp+=str.charAt(i);
			}
			else if (0 <= str.charAt(i) && str.charAt(i) <= 255)
				temp += (char) ((str.charAt(i) + '0' - 10 + 255) % 255);
			else
				temp += str.charAt(i);
		}
		return temp;
	}
}