Vehicle Petrol Shop Inventory System using Java

The Vehicle Petrol Shop Inventory System is developed using java. The project is built to manage sales and transactions. To make a new transaction, fields such as:items type , qty needs to be selected. If you like to learn point of sales systems step by step, this is the right place to learn from the beginning. In this tutorial useful for making a point of sales system for a small shops.

Paste the following code inside the button Event

  String item;
        double price;
        double qty;
        String option;
        double cal;
        double sum = 0.0;
        
        if(chkPetrol.isSelected())
        {
            item = chkPetrol.getText();
            price = 500;
            qty = Double.parseDouble(txtpqty.getText());
            option = Cbpetrol.getSelectedItem().toString();
            
            if(option.equals("ML"))
            {
                cal = price * qty/1000;
                model =  (DefaultTableModel)jTable1.getModel();
                model.addRow(new Object[]
                {
                    item,
                    price,
                    qty,
                    cal
                    
                });                      
            }
            
            else
            {
                 cal = price * qty;
                model =  (DefaultTableModel)jTable1.getModel();
                model.addRow(new Object[]
                {
                    item,
                    price,
                    qty,
                    cal
                    
                });                
                
                
            } 
        }
         if(chkDiesel.isSelected())
        {
            item = chkDiesel.getText();
            price = 600;
            qty = Double.parseDouble(txtdqty.getText());
            option = Cbdiesel.getSelectedItem().toString();
            
            if(option.equals("ML"))
            {
                cal = price * qty/1000;
                model =  (DefaultTableModel)jTable1.getModel();
                model.addRow(new Object[]
                {
                    item,
                    price,
                    qty,
                    cal
                    
                });                      
            }
            
            else
            {
                 cal = price * qty;
                model =  (DefaultTableModel)jTable1.getModel();
                model.addRow(new Object[]
                {
                    item,
                    price,
                    qty,
                    cal
                    
                });                 
            }
        }
        
          if(chkkoil.isSelected())
        {
            item = chkkoil.getText();
            price = 200;
            qty = Double.parseDouble(txtkqty.getText());
            option = Cbkoil.getSelectedItem().toString();
            
            if(option.equals("ML"))
            {
                cal = price * qty/1000;
                model =  (DefaultTableModel)jTable1.getModel();
                model.addRow(new Object[]
                {
                    item,
                    price,
                    qty,
                    cal
                    
                });                      
            }
            
            else
            {
                 cal = price * qty;
                model =  (DefaultTableModel)jTable1.getModel();
                model.addRow(new Object[]
                {
                    item,
                    price,
                    qty,
                    cal
                    
                });                
            }
        }
        
        for(double i=0; i<jTable1.getRowCount(); i++)
       {

 sum = sum + Double.parseDouble(jTable1.getValueAt((int)i,3).toString());
       }
        txtbill.setText(Double.toString(sum));