how to make shorter hard coded Jframe? - jframe

Question

I'm just a beginner in coding. and we're using Net-beans.
here is the sample output he is expecting or want us to code.
sample output
Our prof. wants us to create a program without using any short-cut or other class(1 class and 1 main method). here is my codes and i want to make it short. is there a possible way?
package chuajframe;
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class ChuaJFrame {
static double price;
static double subTotal = 0;
static double subTotal1 = 0;
static int qty;
static double total = 0;
static double change;
static double bill;
public static void main(String s[]) {
JFrame z = new JFrame("Chua JFrame");
JLabel label = new JLabel("Welcome");
label.setBounds(160, 0, 100, 20);
JLabel a = new JLabel("Descrition Price
Quantity"); a.setBounds(10, 10, 400, 50);
//JLabel a1 = new JLabel("Price"); a1.setBounds(120,10,100, 50);
//JLabel a2 = new JLabel("Quantity"); a2.setBounds(210,10,100, 50);
JTextField b = new JTextField(); b.setBounds(10,50, 70, 20);
JTextField b1= new JTextField(); b1.setBounds(120,50, 70, 20);
JTextField b2= new JTextField(); b2.setBounds(210,50, 70, 20);
JButton b3 = new JButton("Add"); b3.setBounds(300,50,70, 20);
JTextField c = new JTextField(); c.setBounds(10,80, 70, 20);
JTextField c1= new JTextField(); c1.setBounds(120,80, 70, 20);
JTextField c2= new JTextField(); c2.setBounds(210,80, 70, 20);
JButton c3 = new JButton("Add"); c3.setBounds(300,80,70, 20);
JLabel label1 = new JLabel("Your about to purchase the following");label1.setBounds(90, 100, 300,30);
JLabel label2 = new JLabel("Subtotal"); label2.setBounds(280, 120, 300,30);
JLabel d = new JLabel(); d.setBounds(10, 150, 100, 20);
JLabel d1 = new JLabel(); d1.setBounds(120,150,100, 20);
JLabel d2 = new JLabel(); d2.setBounds(210,150,100, 20);
JLabel d3 = new JLabel(); d3.setBounds(300,150,100, 20);
JLabel e = new JLabel(); e.setBounds(10, 180, 100, 20);
JLabel e1 = new JLabel(); e1.setBounds(120,180,100, 20);
JLabel e2 = new JLabel(); e2.setBounds(210,180,100, 20);
JLabel e3 = new JLabel(); e3.setBounds(300,180,100, 20);
JLabel f = new JLabel("Total"); f.setBounds(210, 210, 100, 20);
JLabel f1 = new JLabel(); f1.setBounds(300, 210, 100, 20);
JTextField g = new JTextField(); g.setBounds(250,240,100,20);
JButton g1 = new JButton("Payment"); g1.setBounds(140,240,100, 20);
JLabel h = new JLabel(); h.setBounds(140,270,200, 20);
JLabel h1 = new JLabel(); h1.setBounds(300,270,80, 20);
JLabel i = new JLabel(); i.setBounds(140,285,200, 20);
b3.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e){
d.setText(b.getText());
d1.setText(b1.getText());
d2.setText(b2.getText());
price = Double.parseDouble(d1.getText());
qty = Integer.parseInt(d2.getText());
subTotal = price * qty;
d3.setText(Double.toString(subTotal));
total = subTotal + subTotal1;
f1.setText(Double.toString(total));
b.setText(" ");
b1.setText(" ");
b2.setText(" ");
}});
c3.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent ae){
e.setText(c.getText());
e1.setText(c1.getText());
e2.setText(c2.getText());
price = Double.parseDouble(e1.getText());
qty = Integer.parseInt(e2.getText());
subTotal1 = price * qty;
e3.setText(Double.toString(subTotal1));
total = subTotal + subTotal1;
f1.setText(Double.toString(total));
c.setText(" ");
c1.setText(" ");
c2.setText(" ");
}});
g1.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e){
bill = Double.parseDouble(g.getText());
if(bill>total)
{
change = bill - total;
h.setText("Change");
h1.setText(Double.toString(change));
i.setText("Thank you for purchasing.");
}
else{
h.setText("Sorry insufficient payment.");
i.setText("Please enter your payment again!!");
}
}});
z.add(label);
z.add(a); //z.add(a1); z.add(a2);
z.add(b); z.add(b1); z.add(b2); z.add(b3);
z.add(c); z.add(c1); z.add(c2); z.add(c3);
z.add(label1); z.add(label2);
z.add(d); z.add(d1); z.add(d2); z.add(d3);
z.add(e); z.add(e1); z.add(e2); z.add(e3);
z.add(f); z.add(f1);
z.add(g); z.add(g1);
z.add(h); z.add(h1);
z.add(i);
z.setSize(400,350);
z.setLayout(null);
z.setVisible(true);
z.setLocationRelativeTo(null);
z.setResizable(false);
z.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}

Answer 1

You can do something called compound instantiation with most of your fields.
For example, turn this:
static double price;
static double subTotal = 0;
static double subTotal1 = 0;
static int qty;
static double total = 0;
static double change;
static double bill;
Into this:
static double price = 0, subTotal = 0, subTotal1 = 0, total = 0, change = 0, bill = 0;
static int qty;
Or this:
JTextField b = new JTextField();
JTextField b1= new JTextField();
JTextField b2= new JTextField();
JButton b3 = new JButton("Add");
Into this:
JTextField b = new JTextField(), b1= new JTextField(), b2= new JTextField(), b3 = new JButton("Add");
And then use a for loop to add all the things to z that you need to add at the bottom of your class