Java se项目：记事本

   记事本算是一个小项目，对于新人来说，是适合不过的，既用不到网络编程，也永不到数据库的编程，也暂时不管国际化等！
   项目分析：主类继承了JFrame类，是程序的入口点，这个类放入了菜单栏，状态栏和文本的编辑区域，构造方法里面初始化了菜单的各各按钮。并且定义了事件的抽象数组，这些抽象的数组分别各自定义，这些类都继承了AbstratAction,实现具体的事件处理！
   需要注意的地方：由于我们需要在各个类里面处理事件，用到MyPad里面的属性，或者说是用到里面的变量！因此，我们的每个事件处理类都把MyPad这个类做为其属性，在构造方法时候作为参数传过去！

package cn.com.shizongger;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Font;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;

import javax.swing.*;
import cn.com.action.*;

public class MyPad extends JFrame {

    public JTextPane textPane = new JTextPane();    //文本窗格，编辑窗口

    public JLabel statusBar = new JLabel();    //状态栏

    public JFileChooser fileChooser = new JFileChooser();    //文件选择器

    Action[] actions = null;

    //构造方法
    public MyPad() {
        super("记事本1.0版本");

        //设置文本的字体和文字大小
        textPane.setBackground(Color.LIGHT_GRAY);
        textPane.setForeground(Color.ORANGE);
        textPane.setFont(new Font("TimesRoman", Font.PLAIN, 18));

        Action[] actions = {    //Action数组，各种操作的命令
                new NewAction(this),
                new OpenAction(this),
                new SavaAction(this),
                new CutAction(this),
                new CopyAction(this),
                new PasteAction(this),
                new AboutAction(this),
                new ExitAction(this)
        };
        this.actions = actions;        //将构造方法的actions赋值给类的属性actions

        this.setJMenuBar(createJMenuBar(actions));        //设置菜单栏
        Container container = this.getContentPane();    //获取容器
        container.add(createJToolBar(actions), BorderLayout.NORTH);        //增加工具栏
        container.add(textPane, BorderLayout.CENTER);
        container.add(statusBar, BorderLayout.SOUTH);

        this.addWindowListener(new WindowListener() {

            @Override
            public void windowActivated(WindowEvent arg0) {
            }

            @Override
            public void windowClosed(WindowEvent arg0) {
            }

            @Override
            public void windowClosing(WindowEvent arg0) {
                System.exit(0);
            }

            @Override
            public void windowDeactivated(WindowEvent arg0) {
            }

            @Override
            public void windowDeiconified(WindowEvent arg0) {
            }

            @Override
            public void windowIconified(WindowEvent arg0) {
            }

            @Override
            public void windowOpened(WindowEvent arg0) {
            }

        });
    }

    //创建菜单栏，参数是各个事件，返回菜单栏JMenuBar
    private JMenuBar createJMenuBar(Action[] actions) {
        JMenuBar menuBar = new JMenuBar();        //实例化菜单栏
        JMenu menuFile = new JMenu("文件");
        JMenu menuEdit = new JMenu("编辑");
        JMenu menuAbout = new JMenu("帮助");

        //添加新菜单项
        menuFile.add(new JMenuItem(actions[0]));
        menuFile.add(new JMenuItem(actions[1]));
        menuFile.add(new JMenuItem(actions[2]));
        menuFile.add(new JMenuItem(actions[3]));
        menuFile.add(new JMenuItem(actions[4]));
        menuFile.add(new JMenuItem(actions[5]));
        menuFile.add(new JMenuItem(actions[6]));
        menuFile.add(new JMenuItem(actions[7]));

        menuBar.add(menuFile);
        menuBar.add(menuEdit);
        menuBar.add(menuAbout);

        return menuBar;
    }

    //创建工具条，
    private JToolBar createJToolBar(Action[] actions) {
        JToolBar toolBar = new JToolBar();    //实例化工具条

        for(int i = 0; i < actions.length; i++) {
            JButton button = new JButton(actions[i]);    //实例化新按钮
            button.setRequestFocusEnabled(false);        //设置不需要焦点
            toolBar.add(button);        //增加按钮到工具栏
        }

        return toolBar;
    }

    public static void main(String[] args) {
        MyPad frame = new MyPad();
        frame.setSize(500, 500);
        frame.setVisible(true);
        frame.setLocationRelativeTo(null);
    }
}

package cn.com.action;

import java.awt.event.*;
import javax.swing.*;

import cn.com.shizongger.MyPad;

public class CutAction extends AbstractAction {
    MyPad myPad = null;

    public CutAction(MyPad myPad) {
        super("剪切");
        this.myPad = myPad;
    }
    @Override
    public void actionPerformed(ActionEvent e) {
        myPad.textPane.cut();
    }
}

package cn.com.action;

import java.awt.event.*;
import javax.swing.*;

import cn.com.shizongger.MyPad;

public class CopyAction extends AbstractAction {
    MyPad myPad = null;

    public CopyAction(MyPad myPad) {
        super("复制");
        this.myPad = myPad;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        myPad.textPane.copy();
    }
}

package cn.com.action;

import java.awt.event.ActionEvent;

import javax.swing.AbstractAction;

import cn.com.shizongger.MyPad;

public class PasteAction extends AbstractAction {

    private MyPad  myPad = null;

    public PasteAction(MyPad myPad) {
        super("粘贴");
        this.myPad = myPad;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        myPad.textPane.paste();
    }
}

package cn.com.action;

import java.awt.event.ActionEvent;

import javax.swing.AbstractAction;
import javax.swing.JOptionPane;

import cn.com.shizongger.MyPad;

public class AboutAction extends AbstractAction {

    MyPad myPad = null;

    public AboutAction(MyPad myPad) {
        super("关于");
        this.myPad = myPad;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        String output = "文本编辑器1.0版本\n" +
                "作者：张仕宗\n" +
                "日期：2015.5，8\n" +
                "这是学习java以来的第一个比较综合的项目\n" +
                "你的支持是我前进的动力";

        JOptionPane.showMessageDialog(myPad, output);
    }
}

package cn.com.action;

import java.awt.event.*;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import javax.swing.*;

import cn.com.shizongger.MyPad;

public class ExitAction extends AbstractAction {

    private MyPad myPad = null;

    public ExitAction(MyPad myPad) {
        super("退出");
        this.myPad = myPad;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        File f = myPad.fileChooser.getSelectedFile();

        //如果文件不存在，那么直接推出
        if(f != null) {
            int option = JOptionPane.showConfirmDialog(null, "要保存文本么？");
            if(JOptionPane.YES_OPTION == option){
                try {
                    OutputStream os = new FileOutputStream(f);
                    try {
                        os.write(myPad.textPane.getText().getBytes());
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                } catch (FileNotFoundException e1) {
                    e1.printStackTrace();
                }
                System.exit(0);
            }else if(JOptionPane.CANCEL_OPTION == option) {
                return;
            }
        }
        System.exit(0);
    }
}