بليييييييييييز ساعدوني شباب وصبايا الجافا

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

public class CalcSAid extends JFrame implements ActionListener {

private JTextField jTFdisplay;
private double RHS,LHS;
char operator = '=';

public CalcSAid() {

setTitle("Calc");
jTFdisplay = new JTextField();
add(jTFdisplay,BorderLayout.NORTH);
JPanel JPNumbers = new JPanel();
JPNumbers.setLayout(new GridLayout(3,5));
JButton Jb;
for(int i = 1; i <= 9; i++) {
Jb = new JButton(""+i);
JPNumbers.add(Jb);
Jb.addActionListener(this);

}

Jb = new JButton("0");
JPNumbers.add(Jb);
Jb.addActionListener(this);

Jb = new JButton("+");
JPNumbers.add(Jb);
Jb.addActionListener(this);

Jb = new JButton("-");
JPNumbers.add(Jb);
Jb.addActionListener(this);

Jb = new JButton("*");
JPNumbers.add(Jb);
Jb.addActionListener(this);

Jb = new JButton("/");
JPNumbers.add(Jb);
Jb.addActionListener(this);

Jb = new JButton("=");
JPNumbers.add(Jb);
Jb.addActionListener(this);

Jb = new JButton("C");
JPNumbers.add(Jb);
Jb.addActionListener(this);

add(JPNumbers,BorderLayout.CENTER);
pack();
}

public static void main(String[] args) {

CalcSAid c = new CalcSAid();
c.setVisible(true);
c.setSize(300,300);
c.setLocationRelativeTo(null);
c.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

public void actionPerformed(ActionEvent e) {

char a = e.getActionCommand().charAt(0);
switch(a) {
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
jTFdisplay.setText(jTFdisplay.getText()+e.getActionCommand());
break;
case '+':
RHS= Double.parseDouble(jTFdisplay.getText());
operator = '+';
jTFdisplay.setText("");
break;
case '-':
RHS= Double.parseDouble(jTFdisplay.getText());
operator = '-';
jTFdisplay.setText("");
break;
case '*':
RHS= Double.parseDouble(jTFdisplay.getText());
operator = '*';
jTFdisplay.setText("");
break;
case '/':
RHS= Double.parseDouble(jTFdisplay.getText());
operator = '*';
jTFdisplay.setText("");
break;
case 'C':
jTFdisplay.setText("");
break;
case '=':
LHS=Double.parseDouble(jTFdisplay.getText());

switch (operator) {
case '+':
jTFdisplay.setText(""+(RHS + LHS));
break;
case '-':
jTFdisplay.setText(""+(RHS - LHS));
break;
case '*':
jTFdisplay.setText(""+(RHS * LHS));
break;
case '/':
jTFdisplay.setText(""+(RHS / LHS));
break;

}
}
}
}

 import java.awt.*;