Question

java.applet

java.awt

java.awt.event

java.swimg.JOptionPane

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