Question

Make a JAVA program:

java.applet

java.awt

java.awt.evet

java.swing.JOptionpane

decisional structure (IF, ELSE IF), message box, checkbox, number format.

Data entry:

Customer name

Client number

Discount: New Customer 10% Existing Customer 5%

Registration: Daily $ 5 Weekly $ 20 Monthly $ 40 Yearly $ 80

Calculate the registration cost in a function according to the discount and type of registration

It should show the cost and a message box showing the selected alternatives; Result boxes must be visible when the button is pressed and cannot be altered. You must contemplate the different errors, use "try and catch". Create color and apply to shape.

Add button to clear text boxes and variables.

Make a JAVA program decisional structure, message box, matching box, number format.

Entry of Data:

Customer Name

Customer Number

Discount: New Customer 10% Existing Customer 5%

Registration: Daily $5 Weekly $20 Monthly $40 Annual $80

Calculate in a function the cost of registration according to the discount and type of registration

You must display the cost and a message box showing the selected alternatives; the result boxes must be visible when the button is pressed and cannot be altered. You must contemplate the different errors, use " try and catch". Create color and apply to the form.

Add button to clear text boxes and variables.

Answer 1

package GUI;

import javax.swing.*;

import java.awt.*;
import java.awt.event.*;

// Defines class Customer
class Customer
{
   // Instance variables to store customer information
   String customerName;
   String clientNumber;
  
   // Parameterized constructor
   Customer(String cna, String cn)
   {
       customerName = cna;
       clientNumber = cn;
   }
  
   // Method to return customer information
   public String toString()
   {
       return "\n Name: " + customerName + "\n Client Number: " + clientNumber;
   }
}// End of class Customer

// Defines class Discount derived from super class Applet
// implements interface ActionListener
public class Discount extends JApplet implements ActionListener
{
   // Declares component objects
   JLabel cnaL, cnL, regL;
   JTextField cnaT, cnT;
   JCheckBox daily, weekly, monthly, yearly;
   ButtonGroup bg;
   JButton addB;
  
   // Declares JPanel objects
   JPanel jp1, jp2, jp3, jp4, mainJP;
  
   // Declares an array of object of class Customer
   Customer []customers;
   // To store number of customers
   int numberOfCustomer;
  
   // Overrides init() method of Applet
   public void init()
   {
       // Creates the array of object of type Customer
       customers = new Customer[10];
       // Initializes number of objects
       numberOfCustomer = 0;
      
       // Creates panels
       jp1 = new JPanel();
       jp2 = new JPanel();
       jp3 = new JPanel();
       jp4 = new JPanel();
       mainJP = new JPanel();
      
       // Creates labels
       cnaL = new JLabel("Enter customer name: ");
       cnL = new JLabel("Enter customer number: ");
       regL = new JLabel("Registration: ");
      
       // Creates text fields
       cnaT = new JTextField(20);
       cnT = new JTextField(20);
      
       // Creates radio buttons
       daily = new JCheckBox("Daily $5");
       weekly = new JCheckBox("Weekly $ 20");
       monthly = new JCheckBox("Monthly $ 40");
       yearly = new JCheckBox("Yearly $ 80");

       // Creates button group
       bg = new ButtonGroup();
       // Adds radio buttons to button group
       bg.add(daily);
       bg.add(weekly);
       bg.add(monthly);
       bg.add(yearly);
      
       // Creates the button
       addB = new JButton("Add");
       // Registers the button for event handling
       addB.addActionListener(this);
      
       // Adds the label and text field to panel 1
       jp1.add(cnaL);
       jp1.add(cnaT);
       jp1.add(cnL);
       jp1.add(cnT);
       // Sets the layout to 2 rows and 2 columns
       jp1.setLayout(new GridLayout(2, 2));
      
       // Adds the registration label to panel 2
       jp2.add(regL);
      
       // Adds the radio buttons to panel 3
       jp3.add(daily);
       jp3.add(weekly);
       jp3.add(monthly);
       jp3.add(yearly);
       // Sets the layout to 2 rows and 2 columns
       jp3.setLayout(new GridLayout(2, 2));
      
       // Adds button to panel 4
       jp4.add(addB);
      
       // Adds panels to main panel
       mainJP.add(jp1);
       mainJP.add(jp2);
       mainJP.add(jp3);
       mainJP.add(jp4);
       // Sets the layout to 4 rows and one column
       mainJP.setLayout(new GridLayout(4, 1));
      
       // Adds main panel to applet
       add(mainJP);
       // Sets the size of the Applet
       setSize(350, 150);
   }// End of method
  
   // Method to return true if parameter number is available in
   // Array of object customers (Existing customer)
   // Otherwise returns false (New customer)
   boolean isAvailable(String name, String number)
   {
       // Loops till number of customers
       for(int c = 0; c < numberOfCustomer; c++)          
           // Checks if current client number is equals to parameter number
           if(customers[c].clientNumber.equalsIgnoreCase(number) &&
                   customers[c].customerName.equalsIgnoreCase(name))
               // Returns true for Existing customer
               return true;
      
       // Returns false for New customer
       return false;
   }// End of method
  
   // Override actionPerformed of ActionListener interface  
   public void actionPerformed(ActionEvent e)
   {
       double amount = 0;
       double discount;
       String type = "";
       String customer = "";
      
       // try block begins
       try
       {
           // Extracts the customer name
           String name = cnaT.getText();
          
           // Checks if name is blank then throws an exception
           if(name.isEmpty())
               throw new NullPointerException("Please enter Customer Name.");
          
           // Extracts the customer number
           String no = cnT.getText();
          
           // Checks if number is blank then throws an exception
           if(no.isEmpty())
               throw new NullPointerException("Please enter Customer Number.");          
          
           // Checks if all three radio button not selected then throws an exception
           if(!daily.isSelected() && !weekly.isSelected() &&
                   !monthly.isSelected() && !yearly.isSelected())
               throw new NullPointerException("Please select Registration Type.");
          
           // Checks if daily radio button selected
           // then sets the amount and type
           if(daily.isSelected())
           {
               amount = 5;
               type = "Daily";
           }
          
           // Otherwise checks if weekly radio button selected
           // then sets the amount and type
           else if(weekly.isSelected())
           {
               amount = 20;
               type = "Weekly";
           }
          
           // Otherwise checks if monthly radio button selected
           // then sets the amount and type
           else if(monthly.isSelected())
           {
               amount = 40;
               type = "Monthly";
           }
           // Otherwise yearly radio button selected
           // then sets the amount and type
           else
           {
               amount = 80;
               type = "Yearly";
           }          
          
           // Calls the method to check for existing customer or new customer
           // If existing customer then sets the discount and customer type
           if(isAvailable(name, no))
           {
               discount = 10;
               customer = "Existing Customer";              
           }
          
           // Otherwise new customer then sets the discount and customer type
           else
           {
               discount = 5;
               customer = "New Customer";
           }
           // Subtracts the discount
           amount -= (amount * discount) / 100.0;
          
           // Checks if number of customer is equals to maximum length
           // then throws exception
           if(numberOfCustomer == customers.length)              
               throw new IndexOutOfBoundsException("Cannot add more customer. " +
                       "Reached maximum.");
          
           // Otherwise creates an object of Customer using parameterized
           // constructor and assigns it to number of customer index position
           else
               customers[numberOfCustomer++] = new Customer(name, no);
                      
           // Displays information
           JOptionPane.showMessageDialog(null, customers[numberOfCustomer-1] +
                   "\n Customer Type: " + customer + "\n Registration Type: " + type +
                   "\n Discount: " + discount + "% \n Amount: $" + amount,
                   "Payment", JOptionPane.INFORMATION_MESSAGE);
          
           cnaT.setText("");
           cnT.setText("");
           daily.setSelected(false);
           weekly.setSelected(false);
           monthly.setSelected(false);
           yearly.setSelected(false);
          
          
       }
       catch(NullPointerException ne)
       {
           JOptionPane.showMessageDialog(null, ne.getMessage());
       }
       catch(IndexOutOfBoundsException ie)
       {
           JOptionPane.showMessageDialog(null, ie.getMessage());
       }
       catch(RuntimeException re)
       {
           JOptionPane.showMessageDialog(null, re.getMessage());
       }      
   }// End of method
}// End of class

Sample Output: