How to Add multiple textbox values and showing their sum

How can we add multiple textboxes data and show their result in an other textbox using GUI or using a button.
Use TextField to Input multiple data in Java
Get Values from Multiple textbox
Java GUI use one button to add multiple text fields to a text file
how to insert value in multiple text box in java

import java.awt.; import java.awt.event.;
class kframe extends Frame implements ActionListener
{
Checkbox pizza,pepsi,salad;
Label quantity,total;
TextField q1,q2,q3,t1;
Button calculate;
kframe()
{
super(“Place Your Order”);
setBounds(150,150,320,310);
setBackground(new Color(55,105,155));
addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent we)
{
System.exit(0);
}
});
setLayout(null);

pizza=new Checkbox(“PIZZA = 500”);
pizza.setBounds(40,75,130,35);
pizza.setFont(new Font(“Monotype Corsiva”,Font.BOLD,20));

salad=new Checkbox(“SALAD = 50”);
salad.setBounds(40,110,130,35);
salad.setFont(new Font(“Monotype Corsiva”,Font.BOLD,20));

pepsi=new Checkbox(“PEPSI = 50”);
pepsi.setBounds(40,145,130,35);
pepsi.setFont(new Font(“Monotype Corsiva”,Font.BOLD,20));

q1=new TextField(35);
q1.setBounds(180,75,100,25);
q1.setFont(new Font(“Monotype Corsiva”,Font.BOLD,20));
q1.setText(“1”);

q2=new TextField(35);
q2.setBounds(180,110,100,25);
q2.setFont(new Font(“Monotype Corsiva”,Font.BOLD,20));
q2.setText(“1”);

q3=new TextField(35);
q3.setBounds(180,145,100,25);
q3.setFont(new Font(“Monotype Corsiva”,Font.BOLD,20));
q3.setText(“1”);

t1=new TextField(35);
t1.setBounds(180,195,100,25);
t1.setFont(new Font(“Monotype Corsiva”,Font.BOLD,20));

quantity=new Label(“QUANTITY “);
quantity.setBounds(180,40,130,25);
quantity.setFont(new Font(“Monotype Corsiva”,Font.BOLD,20));

total=new Label(“TOTAL “);
total.setBounds(50,195,100,25);
total.setFont(new Font(“Monotype Corsiva”,Font.BOLD,20));

calculate=new Button(“Calculate “);
calculate.setBounds(100,250,100,25);
calculate.setBackground(new Color(55,255,55));
calculate.setFont(new Font(“Monotype Corsiva”,Font.BOLD,20));
calculate.addActionListener(this);

add(quantity);
add(pizza);
add(q1);
add(pepsi);
add(q2);
add(salad);
add(q3);
add(total);
add(t1);
add(calculate);

setVisible(true);
}

public void actionPerformed(ActionEvent ae)
{
int t=0,f=0;
String str=” “;
if(ae.getSource()==calculate)
{
if(pizza.getState())
t=t+(500Integer.parseInt(q1.getText())); if(pepsi.getState()) t=t+(50Integer.parseInt(q2.getText()));
if(salad.getState())
t=t+(50*Integer.parseInt(q3.getText()));
t1.setText(str.valueOf(t));
}
}
}
class b4
{
public static void main(String str[])
{
kframe f=new kframe();
}
}