java GUI设计简单的计算器

package 计算器;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.Scanner;
public class Application extends JFrame {
         
           Calculator panel1;
           JButton[] button = new JButton[16];
         JPanel panel2;
   
         JPanel panel3;
         JButton button3;
        
         String[] s1 = {"0","1","2","3","4","5","6"
           ,"7","8","9","+","-","X","÷",".","="
         };
 public static void main(String[] args){
          Application Ap = new Application();
 }
 
 public Application() {
  setSize(300,300);
  setLocation(100,100);
  setTitle("计算器");
  
  for(int i = 0;i < 16;i ++) {
   button[i] = new JButton(s1[i]);
   button[i].setFont(new Font("华文琥珀",Font.PLAIN,26));
  }
  
  
  panel1 = new Calculator();
  panel3 = new JPanel();
  
  button3 = new JButton("清空");
  //button3.setBackground(Color.lightGray);
  button3.setFont(new Font("华文琥珀",Font.PLAIN,26));
  button3.addActionListener(panel1);
  button3.setActionCommand("清空");
 
  add(panel1,BorderLayout.NORTH);
  panel3.setLayout(new BorderLayout());
  panel3.add(button3,BorderLayout.CENTER);
 
  add(panel3,BorderLayout.SOUTH);
  
  panel2 = new JPanel();
  panel2.setLayout(new GridLayout(4,4));
  
  for(int i = 0;i < 16;i++) {
   panel2.add(button[i]);
  }
  
  add(panel2,BorderLayout.CENTER);
      for(int i = 0;i < 16;i++) {
       button[i].addActionListener(panel1);
      }
  setVisible(true);
  setResizable(false);
  setDefaultCloseOperation(EXIT_ON_CLOSE);
 }

}
class  Calculator extends JPanel implements ActionListener{
    JTextField text = new JTextField(33);
   
   String s;
     public Calculator() {
   this.add(text);
  //text.setSize(20,43);
   text.setFont(new Font("楷体",Font.PLAIN,16));
   text.setEditable(false);
  }
 @Override
 public void actionPerformed(ActionEvent e) {
  String ch1 = text.getText();
  String  ch2 = e.getActionCommand();
  text.setText(ch1+ch2);
   
        if(e.getActionCommand().equals("=")) {
         String ss = text.getText();
      int length = ss.length();
       s = ss.substring(0,length-1); 
      
  //提取数字
  String[] s1 = s.split("[^0123456789.]+");
  int m = s1.length;
  //提取运算符
  String[] s2 = s.split("[1234567890.]+");
  int n = s1.length;
 
       double num;
     
       int count1 = m;
       int count2 = 0;
  //System.out.print(n);
  for(int i = 1; i < n; i ++) {
   if(s2[i].equals("X")) {
    num = Double.parseDouble(s1[i-1])*Double.parseDouble(s1[i]);
    
    s1[i-1] = String.valueOf(num);
    count1 --;
    count2 ++;
    for(int x = i ; x < m - 1; x ++) {
     s1[x] = s1[x+1];
    }
    for(int y = i; y < n - 1; y ++) {
     s2[y] = s2[y+1];
    }
    n--;
    i--;
   }
   if(s2[i].equals("÷")) {
    num = Double.parseDouble(s1[i-1])/Double.parseDouble(s1[i]);
    
    s1[i-1] = String.valueOf(num);
    
    count1 --;
    count2 ++;
    
    for(int x = i; x < m - 1; x ++) {
     s1[x] = s1[x+1];
    }
    for(int y = i; y < n - 1; y ++) {
     s2[y] = s2[y+1];
    }
    n--;
    i--;
   }
  }
  
   double sum = Double.parseDouble(s1[0]);
  for(int i = 1; i < n; i ++) {
   if(s2[i].equals("+")) {
    
    sum+=Double.parseDouble(s1[i]);
   }
   else {
    sum-=Double.parseDouble(s1[i]); 
   }
  }
  text.setText(String.valueOf(sum));
 }
        if(e.getActionCommand().equals("清空")) {
         text.setText("");
        }
}
}