10 – Easy and simple java program for billing system of tour and travels

import java.awt.event.*;
import javax.swing.*;
import java.util.*;
//itvoyagers.in
public class Ticket extends JFrame implements ActionListener
{
    int space = 30, age;
    float cost, total_service_tax = 0.0f, final_amount;
    
    JLabel ticket_name_label, non_ac_price_label, ac_price_label;
    JLabel name_label, age_label;
    JLabel name_list_label, age_list_label, cost_list_label;
    JLabel service_tax_text_label, service_tax, total_text_label, total;
//itvoyagers.in    
    JTextField name_text_field[] = new JTextField[3];
    JTextField age_text_field[] = new JTextField[3];
    
    JCheckBox ac;
    
    JButton book;
    
    JList name_list, age_list, price_list;
    
    DefaultListModel<String> name_bill, age_bill, price_bill;
//itvoyagers.in    
    public Ticket()
    {
        ticket_name_label = new JLabel("Mumbai To Pune");
        non_ac_price_label = new JLabel("Non-AC : ₹400/-");
        ac_price_label = new JLabel("AC : ₹550/-");
        
        name_label = new JLabel("Name");
        age_label = new JLabel("Age");
        
        name_list_label = new JLabel("Name");
        age_list_label = new JLabel("Age");
        cost_list_label = new JLabel("Cost");
        
        ac = new JCheckBox("AC");
        
        book = new JButton("Book");
//itvoyagers.in        
        service_tax_text_label = new JLabel("4% Service Tax");
        total_text_label = new JLabel("Total Amount");
        service_tax = new JLabel();
        total = new JLabel();
        
        name_bill = new DefaultListModel<>();
        age_bill = new DefaultListModel<>();
        price_bill = new DefaultListModel<>();
        
        name_list = new JList(name_bill);
        age_list = new JList(age_bill);
        price_list = new JList(price_bill);
        
        for (int i = 0; i < 3; i++)
        {
            name_text_field[i] = new JTextField();
            name_text_field[i].setBounds(10, (i+6)*10+space, 200, 20);
            add(name_text_field[i]);
            
            age_text_field[i] = new JTextField();
            age_text_field[i].setBounds(250, (i+6)*10+space, 100, 20);
            add(age_text_field[i]);
            
            space += 30;
        }
//itvoyagers.in        
        ticket_name_label.setBounds(140, 10, 200, 20);
        non_ac_price_label.setBounds(10, 40, 200, 20);
        ac_price_label.setBounds(250, 40, 100, 20);
        
        name_label.setBounds(10, 70, 50, 20);
        age_label.setBounds(250, 70, 50, 20);
        
        ac.setBounds(100, 199, 50, 20);
        
        book.setBounds(175, 195, 100, 30);
        
        name_list_label.setBounds(10, 230, 50, 20);
        age_list_label.setBounds(230, 230, 30, 20);
        cost_list_label.setBounds(300, 230, 50, 20);
        
        name_list.setBounds(10, 260, 200, 100);
        age_list.setBounds(230, 260, 50, 100);
        price_list.setBounds(300, 260, 50, 100);
        
        service_tax_text_label.setBounds(100, 370, 100, 20);
        total_text_label.setBounds(100, 390, 100, 20);
        service_tax.setBounds(300, 370, 100, 20);
        total.setBounds(300, 390, 100, 20);
//itvoyagers.in        
        add(ticket_name_label);
        add(non_ac_price_label);
        add(ac_price_label);
        
        add(name_label);
        add(age_label);
        
        add(ac);
        
        add(book);
        
        add(name_list_label);
        add(age_list_label);
        add(cost_list_label);
        
        add(name_list);
        add(age_list);
        add(price_list);
        
        add(service_tax_text_label);
        add(total_text_label);
        add(service_tax);
        add(total);
        
        book.addActionListener(this);
//itvoyagers.in        
        setSize(375,460);
        setLayout(null);
        setVisible(true);
        setTitle("My Ticket");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    
    @Override
    public void actionPerformed(ActionEvent e) 
    {
        if(e.getSource()==book)
        {
            float amount_without_service_tax = 0.0f;
            
            clear_all();
            
            cost = ac.isSelected() ? 550 : 400;
//itvoyagers.in            
            for(int i = 0; i < 3; i++)
            {                
                try
                {
                    age = Integer.parseInt(age_text_field[i].getText());
                    
                    if((age < 5 || age > 65) && age<100)
                    {
                        price_bill.addElement(Float.toString(cost/2));
                    }
                    else if(age>=5 && age<=65)
                    {
                        price_bill.addElement(Float.toString(cost));
                    }
                    else
                    {
                        JOptionPane.showMessageDialog(this, "Please enter valid age");
                        age_text_field[i].setText("");
                        break;
                    }
                    
                    name_bill.addElement(name_text_field[i].getText());
                    age_bill.addElement(age_text_field[i].getText());
                }
                catch(NumberFormatException exp)
                {
                    JOptionPane.showMessageDialog(this, "Something went worngn1. Please check for blank fieldsn2. Please enter numeric values in age");
                    age_text_field[i].setText("");
                    clear_all();
                    break;
                }
            }
//itvoyagers.in            
            for(int i=0;i<price_bill.getSize();i++)
            {
                amount_without_service_tax += Float.parseFloat(price_bill.getElementAt(i));
            }
            
            total_service_tax = amount_without_service_tax * 0.04f;
            final_amount = amount_without_service_tax + total_service_tax;
            
            service_tax.setText(Float.toString(total_service_tax));
            total.setText(Float.toString(final_amount));
        }
    }
//itvoyagers.in    
    public void clear_all()
    {
            name_bill.clear();
            age_bill.clear();
            price_bill.clear();
    }
//itvoyagers.in
    public static void main(String[] args)
    {
        Ticket ticket = new Ticket();
    }
}