想编一个java swing的窗口程序，总是不对……怎么办呀T_T（附代码）

想编一个计算窗口，有两个按钮分别是Count Up 和 Count Down，功能为加1和减1，一行字为“Count is：0” 
后面那个0就是如果点Count Up按钮，就变成1，再点就变2……，同理点Count Down时那个0就减1，变成负的也可以。
我编的代码如下：

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

public class Counter extends JFrame
{
       public Counter()
    {
       super("Counter");
       
       JPanel counting=new JPanel();
       counting.setLayout(new FlowLayout());
       
       JButton countUp=new JButton("Count Up");
       JButton countDown=new JButton("Count Down");

       counting.add(countUp);
       counting.add(countDown);
       
      counting.add(new JLabel("Count is:"));
       
        add(counting);
          
       setContentPane(counting);
       pack();
       setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       setVisible(true);
       
       countUp.addActionListener(new ActionListener()
       {
            public void actionPerformed(ActionEvent event1)
          {
              if (countUp.isSelected())  //这个地方出错了，说内部类引用时要先定义为final
           {
             int n=n+1;
             counting.add(new JLabel("Count is:"+n)); 
           }
        }
      });
       countDown.addActionListener(new ActionListener()
       {
           public void actionPerformed(ActionEvent event2)
           {
              if (countDown.isSelected())
            {
               int n=n-1;
               counting.add(new JLabel("Count is:"+n));
            }
           }
        });
    }
        public static void main (String args[])
      {
        new Counter();
      }
    }

我是菜鸟级的。。。求指导！！！！！谢谢啦！！！

答案：package com;

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

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class Counter extends JFrame {
	JLabel label = new JLabel("Count is:");
	public Counter() {
		super("Counter");

		final JPanel counting = new JPanel();
		counting.setLayout(new FlowLayout());

		final JButton countUp = new JButton("Count Up");
		final JButton countDown = new JButton("Count Down");
		countUp.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event1) {
				A.n++;
				label.setText("Count is:" + A.n);
				//counting.add(new JLabel("Count is:" + A.n));

			}
		});
		countDown.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event2) {

				A.n--;
				label.setText("Count is:" + A.n);
				//counting.add(new JLabel("Count is:" + A.n));

			}
		});
		counting.add(countUp);
		counting.add(countDown);

		counting.add(label);

		add(counting);

		setContentPane(counting);
		pack();
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setVisible(true);

	}
	public static void main(String args[]) {
		new Counter();
	}
}
class A {
	static public int n = 0;
}

其他：不知道 不是 .isSelected()，你看看有没有按钮按一下那个函数。 

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