开始写java博客了,希望能够坚持下去

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java 代码

package com.examples;

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.JButton;
import javax.swing.JPanel;



public class ToolBarFrame2 extends Frame {
    JButton cutButton,copyButton,pasteButton;
    JButton javaButton,macButton,motifButton,winButton;

    public ToolBarFrame2() {
        super("ToolBar Example ( Swing )");
        // TODO Auto-generated constructor stub
        setSize(450, 250);
        addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent arg0) {
                // TODO Auto-generated method stub
                System.exit(0);
            }
        });
        JPanel toolbar = new JPanel();
        toolbar.setLayout(new FlowLayout(FlowLayout.LEFT));
        cutButton = new JButton("Cut");
        ActionListener printListener = new ActionListener(){

            public void actionPerformed(ActionEvent ae) {
                // TODO Auto-generated method stub
                System.out.println(ae.getActionCommand());
            }


        };
        cutButton.addActionListener(printListener);
        toolbar.add(cutButton);

        copyButton = new JButton("Copy");
        copyButton.addActionListener(printListener);
        toolbar.add(copyButton);

        pasteButton = new JButton("Paste");
        pasteButton.addActionListener(printListener);
        toolbar.add(pasteButton);

        add(toolbar,BorderLayout.NORTH);

        JPanel lnfPanel = new JPanel();
        LnFListener lnfListener = new LnFListener(this);
        macButton = new JButton("Mac");
        macButton.addActionListener(lnfListener);
        lnfPanel.add(macButton);

        javaButton = new JButton("Metal");
        javaButton.addActionListener(lnfListener);
        lnfPanel.add(javaButton);

        motifButton = new JButton("Motif");
        motifButton.addActionListener(lnfListener);
        lnfPanel.add(motifButton);

        winButton = new JButton("Windows");
        winButton.addActionListener(lnfListener);
        lnfPanel.add(winButton);
        add(lnfPanel,BorderLayout.SOUTH);


    }
    public static void main(String[] args) {
        ToolBarFrame2 tf1 = new ToolBarFrame2();
        tf1.setVisible(true);
    }

}

LnFListener代码

package com.examples;

import java.awt.Frame;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;

public class LnFListener implements ActionListener {
    Frame frame;

    public LnFListener(Frame frame) {
        super();
        // TODO Auto-generated constructor stub
        this.frame = frame;
    }

    public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub
        String lnfName = null;
        String actionCommand = e.getActionCommand();
        System.out.println(actionCommand);
        if(actionCommand.equals("Mac")){
            //lnfName="com.apple.mrj.swing.MacLookAndFeel";
            lnfName="com.apple.mrj.swing.MacLookAndFeel";
        }else if(actionCommand.equals("Metal")){
            lnfName="javax.swing.plaf.metal.MetalLookAndFeel";
        }else if(actionCommand.equals("Motif")){
            lnfName = "com.sun.java.swing.plaf.motif.MotifLookAndFeel";
        }else if(actionCommand.equals("Windows")){
            lnfName = "com.sun.java.swing.plaf.windows.WindowsLookAndFeel";
        }else{
            System.err.print("Unjfj");
            return;
        }
        try {
            UIManager.setLookAndFeel(lnfName);
            SwingUtilities.updateComponentTreeUI(frame);
        } catch (ClassNotFoundException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        } catch (InstantiationException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        } catch (IllegalAccessException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        } catch (UnsupportedLookAndFeelException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

    }

}

我发现一个问题了,

当我点击:"Mac"按钮的时候,却会出错,报的错是:

Mac
java.lang.ClassNotFoundException: com.apple.mrj.swing.MacLookAndFeel
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)

我想这里的的原因是在于"com.apple.mrj.swing.MacLookAndFeel";各位有谁知道,这个错误该怎么改吗?