按下JButton时重绘方法不起作用

Question

我正在编写此程序，其中有5个面板，两个面板分别称为RightPanel和LeftPanel，彼此相邻。 RightPanel是一个JPanel，包含一个JButton和一个文本字段。主要问题在于JButton。每当我单击名为“鼻子”的按钮时，LeftPanel（即RightPanel旁边的另一个面板）都应该绘制黄色椭圆形。当我尝试这样做时，它不起作用。

我尝试了e.getSouce ==鼻子，但是它也没有用，所以我尝试了getActionCommand。我知道我应该使用重新粉刷，这就是我正在尝试的方法，但是它不起作用。

这是我的代码。

    // SneezePanels.java
/*  IDEA of this program:  PanelHolder, which is added to the frame, holds two panels,
LeftPanel and RightPanel, which are added to PanelHolder in a GridLayout. The 
LeftHolder has a BorderLayout and has two panels-a direction panel, with a FlowLayout 
that has a the button, and a textField panel that contains the textField.  When
the button is pressed, Achoo and a yellow oval are drawn on the Right Panel.  
When the user types in "Bless you" in the textField, the RightPanel is erased
and variables are reset.
*/
/// Testing:  Only clicking on the button will draw on the right panel.  Only typing 
/// in "Bless you" will clear it.
/// Try clicking anywhere other that the button.  This should will not change anything.  
/// Typing anything other than "Bless you" will not reset the panels.

import java.awt.event.ActionListener;   
import java.awt.event.ActionEvent;

import javax.swing.JButton;
import javax.swing.JFrame;  
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;

import java.awt.Color;      
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Font;

import java.awt.BorderLayout;
import java.awt.FlowLayout;

public class SneezePanels
{   
    public static void main( String[] args )
    {
        SneezePanels sp = new SneezePanels();
        sp.run();
    }

    public SneezePanels()
    {   
    }

    public void run()
    {
        JFrame sneezeFrame = new JFrame ("Sneeze and Bless you.");

        sneezeFrame.setSize( 600, 400);             
        sneezeFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
        sneezeFrame.setLocation(400,50);
        sneezeFrame.setResizable(true);
        PanelHolder pHolder = new PanelHolder(); 
        sneezeFrame.add( pHolder );     
        sneezeFrame.setVisible(true);   
    }

    // This panel holds two panels-one on the left and one on the right, aptly 
    named
class PanelHolder extends JPanel
{
    private RightPanel rp;  // these are field variables so the nested classes have access to them
    private boolean nosePressed;    // otherwise, we have to use getter-setter methods
    private Font font;

    private JButton nose; 
    private JTextArea directions;


    public PanelHolder()
    {
        setLayout( new GridLayout(1, 2) );
        nosePressed = false;
        font = new Font("Serif", Font.BOLD, 20);

        LeftPanel lp = new LeftPanel();
        add(lp);
        rp = new RightPanel();
        add( rp );
    }

    // This panel will have a BorderLayout
    //  It will have the directions panel in the center, and the 
    // textField panel in the south. 
    class LeftPanel extends JPanel
    {   
        public LeftPanel()
        {   
            setLayout(new BorderLayout());
            // setBackground( Color.MAGENTA );

            DirectionPanel dirP = new DirectionPanel ();
            TFPanel tfp = new TFPanel();

            add ( dirP, BorderLayout.CENTER );
            add ( tfp, BorderLayout.SOUTH );
        }

    }

    // DirectionPanel will print the directions and contain the 
    // nose button.  It has a FlowLayout.  It will use a 
    // ButtonHandler for actionPerformed.
    class DirectionPanel extends JPanel
    {

        public DirectionPanel()
        {
            setLayout(new FlowLayout());

            nose = new JButton("nose");
            add(nose);

            directions = new JTextArea("Directions: Press button to tickle the nose.");
            add(directions);

            setBackground(Color.RED);
        }   

        public void paintComponent( Graphics g )
        {
            super.paintComponent(g);

        }

    }

    // The TFPanel will have a FlowLayout and contain a text field
    // that will be on the left.  It uses a handler class for 
    // actionPerformed
    class TFPanel extends JPanel
    {
        private JTextField blessYou;

        public TFPanel()
        {
            setLayout(new FlowLayout());
            blessYou = new JTextField("Type: 'Bless you.'");

            add(blessYou);

        }
    }

    // The RightPanel is used to draw "Achoo" and a yellow oval when the
    // button is pressed and cleared when "Bless you" is typed in
    // the textField
    class RightPanel extends JPanel
    {
        public RightPanel()
        {
        }

        public void paintComponent(Graphics g)
        {
            super.paintComponent(g);

            if(nosePressed)
            {
                g.setColor(Color.YELLOW);
                g.fillOval(100, 100, 40, 50);
            }

        }

    }

    // When the button is pressed, the method actionPerformed is 
    // used to call paintComponent in RightPanel
    class Button1Handler implements ActionListener 
    {
        public Button1Handler()
        {
            nose.addActionListener(this);
        }
        public void actionPerformed(ActionEvent e) 
        {

            String pressed = e.getActionCommand();

            if(pressed.equals("nose"))
            {
                System.out.print("l");
                System.out.println("pressed");
                nosePressed = true;
                rp.repaint();
            }
        }
    }   // end class Button1Handler 

    // When the user types in "Bless you" in the textField, the 
    // boolean is reset and RightPanel's paintComponent is called
    class TextFieldHandler implements ActionListener 
    {
        public void actionPerformed(ActionEvent e) 
        {

        }
    }   // end class TextFieldHandler
}
}

是的，我已经导入了所有内容，尽管看起来可能不一样，但我正在使用eclipse，但它并未显示导入。我希望输出是当按下按钮“鼻子”时，在RightPanel上绘制一个黄色的椭圆形。感谢所有帮助。