上学期做了个计算器界面，遗憾没能让它运行，哪位大哥能给个思路

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

import javax.swing.JButton;
import javax.swing.JFrame;
public class GridBagLayoutDemo extends JFrame implements ActionListener{
	public GridBagLayoutDemo(){
		GridBagLayout gridbag=new GridBagLayout();//创建网格包对象
		GridBagConstraints c=new GridBagConstraints();//创建约束条件对象
		
		
		this.setLayout(gridbag);
		c.fill=GridBagConstraints.BOTH;//组件充满显示区域
		c.gridwidth = 0;
       makeButton("0", gridbag, c);
		c.weighty = 1;
		c.weightx = 1;
		c.gridwidth = 1;
		makeButton("1", gridbag, c);
		makeButton("2", gridbag, c);
        makeButton("3", gridbag, c);
		c.gridwidth = GridBagConstraints.REMAINDER;
		makeButton("+", gridbag, c);
		c.gridwidth = 1;
		makeButton("4", gridbag, c);
		makeButton("5", gridbag, c);
        makeButton("6", gridbag, c);
		c.gridwidth = GridBagConstraints.REMAINDER;

		makeButton("-", gridbag, c);
		
		c.gridwidth = 1;
		makeButton("7", gridbag, c);
		makeButton("8", gridbag, c);
		makeButton("9", gridbag, c);
		c.gridwidth = GridBagConstraints.REMAINDER;
		makeButton("*", gridbag, c);
		c.gridwidth = 1;
		makeButton("0", gridbag, c);
		makeButton("=", gridbag, c);
		makeButton(".", gridbag, c);
		c.gridwidth = GridBagConstraints.REMAINDER;
		makeButton("/", gridbag, c);
		
	}
	//创建标签为name的button，并使用约束对象c将按钮加入到gridbag布局
	//的容器中
	private void makeButton(String name,GridBagLayout
			gridbag,GridBagConstraints c){
		JButton button=new JButton(name);
		gridbag.setConstraints(button,c);//将约束条件附加给按钮组件
		add(button);//将按钮加入容器
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		GridBagLayoutDemo window=new GridBagLayoutDemo();
		window.setTitle("GridBagLayout布局管理器");
		window.pack();
		window.setVisible(true);
		window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		// TODO Auto-generated method stu
	}
	@Override
	public void actionPerformed(ActionEvent e) {
		// TODO Auto-generated method stub
		
	}

}

public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub
         
    }