编写程序，创建如下图所示的图形界面。（要求实现功能）

编写程序，创建如下图所示的图形界面。（要求实现功能）

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class sum {
	public static void main(String args[]){
		ComputerFrame frame =new ComputerFrame();
		frame.setTitle("求和");
		frame.setBounds(500,500,800,800);
	}	
}
class ComputerFrame extends JFrame {
	JTextField numberone;
	JTextField numbertwo;
	JTextField result;
	JButton answer;
	JButton clear;
	Sumlistener sumlis;
	Clearlistener clearlis;
	ComputerFrame(){
		init();
		setVisible(true);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
	void init(){
		GridLayout Grid=new GridLayout(3,3);
		setLayout(Grid);
		add(new JLabel("数字1:"));
		numberone=new JTextField(20);
		add(numberone);
		add(new JLabel(" "));
		add(new JLabel("数字2:"));
		numbertwo=new JTextField(20);
		add(numbertwo);
		add(new Label(" "));
		answer=new JButton("求和");
		result=new JTextField(20);
		clear=new JButton("清除");
		add(answer);
		add(result);
		add(clear);
		sumlis=new Sumlistener(numberone,numbertwo,result);
		clearlis=new Clearlistener(numberone,numbertwo,result);
		answer.addActionListener(sumlis);
		clear.addActionListener(clearlis);
	}
}
class Sumlistener implements ActionListener{
	JTextField numberone;
	JTextField numbertwo;
	JTextField result;
	Sumlistener(JTextField one,JTextField two,JTextField res){
		numberone=one;
		numbertwo=two;
		result=res;
	}
	public void actionPerformed(ActionEvent e){
		double a=Double.parseDouble(numberone.getText().trim());
		double b=Double.parseDouble(numbertwo.getText().trim());
		String c=String.valueOf(a+b);
		result.setText(c);
	}
}
class Clearlistener implements ActionListener{
	JTextField numberone;
	JTextField numbertwo;
	JTextField result;
	Clearlistener(JTextField one,JTextField two,JTextField res){
		numberone=one;
		numbertwo=two;
		result=res;
	}
	public void actionPerformed(ActionEvent e){
		numberone.setText(" ");
		numbertwo.setText(" ");
		result.setText(" ");
	}

}