JAVA记事本的图形用户界面应用程序

JAVA记事本的图形用户界面应用程序

整体分析：

代码实现：

import java.awt.EventQueue;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

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.JFrame;

import javax.swing.JMenuBar;

import javax.swing.JMenu;

import javax.swing.JMenuItem;

import javax.swing.JSeparator;

import javax.swing.JTextArea;

import java.awt.BorderLayout;

import java.awt.Font;

/**记事本的图形用户界面应用程序

 * @author 李祖林

 * 2017-6-22

 */

public class Note1 implements ActionListener{

    private JFrame frame;

    JMenuItem New, Open, Save, Close; /*

                                         * New为新建，

                                         * Open为打开

                                         * Save为保存

                                         * Close为关闭

                                         */

    JTextArea textArea;

    File fileName = new File("D:\\file.txt");    //默认打开文件路径

    public static void main(String[] args) {

        EventQueue.invokeLater(new Runnable() {

            public void run() {

                try {

                    Note1 window = new Note1();

                    window.frame.setVisible(true);

                } catch (Exception e) {

                    e.printStackTrace();

                }

            }

        });

    }

    public Note1() {

        frame = new JFrame();

        frame.setFont(new Font("Dialog", Font.BOLD, 18));

        frame.setBounds(100, 100, 629, 412);

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JMenuBar menuBar = new JMenuBar();

        frame.setJMenuBar(menuBar);

        JMenu menu = new JMenu("\u6587\u4EF6");

        menu.setFont(new Font("黑体", Font.BOLD, 18));

        menuBar.add(menu);

        New = new JMenuItem("\u65B0\u5EFA");

        New.setFont(new Font("黑体", Font.BOLD, 18));

        menu.add(New);New.addActionListener(this);

        Open = new JMenuItem("\u6253\u5F00");

        Open.setFont(new Font("黑体", Font.BOLD, 18));

        menu.add(Open);Open.addActionListener(this);

        Save = new JMenuItem("\u4FDD\u5B58");

        Save.setFont(new Font("黑体", Font.BOLD, 18));

        menu.add(Save);Save.addActionListener(this);

        JSeparator separator = new JSeparator();

        menu.add(separator);

        Close = new JMenuItem("\u5173\u95ED");

        Close.setFont(new Font("黑体", Font.BOLD, 18));

        menu.add(Close);Close.addActionListener(this);

        JMenu menu_1 = new JMenu("\u7F16\u8F91");

        menu_1.setFont(new Font("黑体", Font.BOLD, 18));

        menuBar.add(menu_1);

        JMenuItem menuItem_4 = new JMenuItem("\u590D\u5236");

        menu_1.add(menuItem_4);

        JMenuItem menuItem_5 = new JMenuItem("\u7C98\u8D34");

        menu_1.add(menuItem_5);

        JMenuItem menuItem_6 = new JMenuItem("\u526A\u5207");

        menu_1.add(menuItem_6);

        textArea = new JTextArea();

        frame.getContentPane().add(textArea, BorderLayout.CENTER);

    }

    public void actionPerformed(ActionEvent e) {

        if(e.getSource()==Close){

            System.exit(0);

        }

        else if (e.getSource()==Save) {

            saveFile();

        }else if (e.getSource()==Open){

            readFile();

        }else{

            textArea.setText("");

        }

    }

    /*打开文件函数*/

    public void readFile(){

        try{

            BufferedReader bufferedReader = new BufferedReader(new FileReader(fileName));    //缓存字符流

            StringBuffer buffer = new StringBuffer();

            String text;

            while((text = bufferedReader.readLine()) != null){

//                buffer.append(text+"\n");

                textArea.append(text+"\n");

            }

//            textArea.setText(buffer.toString());

            bufferedReader.close();

        }catch (IOException e) {

            System.err.println("读入文件发生错误！");

        }

    }

    /*保存文件函数*/

    public void saveFile(){

        try{

            BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(fileName));

            String string = textArea.getText();

            bufferedWriter.write(string);

            bufferedWriter.close();

        }catch (IOException e) {

            System.err.println("保存文件发生错误！");

        }

    }

}

实验结果：