5.24Java网格布局和多个事件监听

import java.awt.*;
import javax.swing.*;
public class comput {
        JFrame f;
        JPanel p;
        JTextField t; 
        JButton b[];
        GridLayout g;
        String a[]= {"7","8","9","/", 
                "4","5","6","*",
                "1","2","3","-",
                "0",".","=","+"};
        public comput(){
            f = new JFrame();
            p = new JPanel();
            b = new JButton[16];
            t = new JTextField(10);
            g = new GridLayout(4,4);
            p.setLayout(g);            
            for(int i=0;i<16;i++){
                b[i] = new JButton (a[i]);
                p.add(b[i]);
            }
            f.setSize(400, 300);;
            f.add(p);
            f.setTitle("计算器");
            f.setVisible(true);
            f.add(t,BorderLayout.NORTH);
            f.add(p,BorderLayout.CENTER);                              
       }
        public static void main(String[] args) {
            new comput();
            }
}

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class color1 {
    JFrame f;
    JPanel p;
    JButton b1,b2,b3;
    public color1() {
        f = new JFrame();
        p = new JPanel();
        b1 = new JButton("粉红色");
        b2 = new JButton("橘色");
        b3 = new JButton("浅绿色");
        b1.addActionListener(new ActionListener(){
            
            @Override
            public void actionPerformed(ActionEvent e){
                 p.setBackground(Color.pink);}});
        b2.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                p.setBackground(Color.orange);}});
        b3.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                p.setBackground(Color.green);
            }});
        
        f.setSize(400,400);
        f.add(p);
        p.add(b1); p.add(b2); p.add(b3);     
        f.setVisible(true);    
    }
    
    public static void main(String[] args) {
        new color1();
        }      
}