examples.businesspolicy
Class BusinessPolicyExample

java.lang.Object
  |
  +--examples.businesspolicy.BusinessPolicyExample

public class BusinessPolicyExample

extends java.lang.Object

This example demonstrates the concept of "Pluggable Methods", better known as policies. When you create your components, you will realize that many times you want to alter the component behaviour based on external conditions that you can not evaluate at development time. Reusability, extensibility and rapid development and enhancement are typical problems that can be solved using policies. BusinessPolicy is Theory Center's implementation of the Policy and Strategy design patterns. Using this concepts allows you to replace the default policy at runtime. The policy is stored as a property for the item. In this example we will use an item component. The item component has a default pricing policy. The item's price can be calculated in two ways: By supplying only a quantity, you can have the price be calculated based on the default policy; By supplying a pricing policy in addition to a quantity, the item's price can be calculated using the new pricing policy. You can replace the pricing policy to alter the way the price is calculated for the item. This means that you can modify the behaviour of the item by plugging in a method that calculates the price the way you want. The example creates an item. It Then, sets the SeniorCitizenDiscountPolicy as the default pricing policy for the item. Then, the item's price is calculated using the default policy. Finally,it modifies the item quantity and once again, calculates the price; this time using the AprilFoolsDiscountPolicy policy. To better understand this example it would be great if you go through the Axiom example first

See Also:

AxiomExample, Item, ItemPriceCalculationPolicy, BusinessPolicy, AprilFoolsDiscountPolicy, SeniorCitizenDiscountPolicy, Quantity, Price

Field Summary

static java.lang.String

HOME_NAME

Constructor Summary

BusinessPolicyExample()
BusinessPolicyExample default constructor.

Method Summary

void	displayItemDetails(Item item) Displays the description and price of an item.
void	exitExample(java.lang.String message, java.lang.Exception e) Display the message and the exception and terminate the the program
Customer	findOrCreateCustomer(java.lang.String customerKey) Finds or Creates a customer with the given customerKey.
Item	findOrCreateItem(java.lang.String identifier, java.lang.String supplier, java.lang.String version) Obtains the item home from JNDI, it searches for an item with the given primary key.
javax.naming.Context	getInitialContext() Gets an initial context for the current user, password and url.
static void	main(java.lang.String[] argv) The main method of the Business Policy example.
boolean	run() This method is the sequence of the example: 1.- Find or create a new Item with the given primary key 2.- Create an quantity belonging 3.- Create a new SeniorCitizenDiscountPolicy 4.- Calculate the price using the above quantity and policy 5.- Change the count in the quantity 6.- Create a new AprilFoolsDiscountPolicy 7.- Calculate the price using the new quantity and policy

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

HOME_NAME

public static final java.lang.String HOME_NAME

Constructor Detail

BusinessPolicyExample

public BusinessPolicyExample()

BusinessPolicyExample default constructor.

Method Detail

displayItemDetails

public void displayItemDetails(Item item)

Displays the description and price of an item. This method also illustrates the use of the Price component

Parameters:

item - The item that you want to display

See Also:

Price

exitExample

public void exitExample(java.lang.String message,
                        java.lang.Exception e)

Display the message and the exception and terminate the the program

Parameters:

message - The message to display upon termination

e - The exception thrown or null if no exception was thrown

findOrCreateCustomer

public Customer findOrCreateCustomer(java.lang.String customerKey)

Finds or Creates a customer with the given customerKey.

Parameters:

customerKey - the key for the customer

Returns:

the customer's entity bean

findOrCreateItem

public Item findOrCreateItem(java.lang.String identifier,
                             java.lang.String supplier,
                             java.lang.String version)

Obtains the item home from JNDI, it searches for an item with the given primary key. If the item is found it is returned, otherwise a new item with the given primary key is created and returned.

Parameters:

identifier - A unique identifier for the item (SKU)

supplier - The item supplier

version - The catalog version of this item

Returns:

The item with the given primary key

getInitialContext

public javax.naming.Context getInitialContext()
                                       throws java.lang.Exception

Gets an initial context for the current user, password and url.

Returns:

Context

Throws:

java.lang.Exception - if there is an error in getting the Context

main

public static void main(java.lang.String[] argv)

The main method of the Business Policy example. It instantiates and runs a new BusinessPolicy Example

Parameters:

argv - The command line arguments

run

public boolean run()

This method is the sequence of the example: 1.- Find or create a new Item with the given primary key 2.- Create an quantity belonging 3.- Create a new SeniorCitizenDiscountPolicy 4.- Calculate the price using the above quantity and policy 5.- Change the count in the quantity 6.- Create a new AprilFoolsDiscountPolicy 7.- Calculate the price using the new quantity and policy

See Also:

AprilFoolsDiscountPolicy, SeniorCitizenDiscountPolicy, Quantity