scpc

Class Calculator

java.lang.Object

scpc.Calculator

public class Calculator
extends java.lang.Object

Calculator of Shopping cart promotion.

Author:

Kent Yeh

Constructor Summary

Constructors

Constructor and Description
Calculator()

Method Summary

Methods

Modifier and Type	Method and Description
static <T> java.util.Collection<BonusItem<T>>	calcBonus(java.util.List<? extends IRule<T>> rules, java.util.Set<? extends IItem<T>> cartItems) Caculate bonus from rules and shopping cart items.
static <T> java.util.List<SingleItem<T>>	flat(java.util.Set<? extends IItem<T>> cartItems) Spread shopping cart into single item for iteration.
static <T> java.util.List<T>	purification(java.util.Collection<? extends IItem<T>> items) Extract real cart items from a collection.

Methods inherited from class java.lang.Object

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

Constructor Detail

Calculator

public Calculator()

Method Detail

flat

public static <T> java.util.List<SingleItem<T>> flat(java.util.Set<? extends IItem<T>> cartItems)

Spread shopping cart into single item for iteration.
展開購物車以便逐一檢視單個品項

Type Parameters:

T - Type represented of shopping cart item.

Parameters:

cartItems - shopping cart items.

Returns:

purification

public static <T> java.util.List<T> purification(java.util.Collection<? extends IItem<T>> items)

Extract real cart items from a collection.
取出集合中真正的購物品項

Type Parameters:

T - type of real cart item.

Parameters:

items - those wrapped shopping cart items.

Returns:

real cart items

calcBonus

public static <T> java.util.Collection<BonusItem<T>> calcBonus(java.util.List<? extends IRule<T>> rules,
                                               java.util.Set<? extends IItem<T>> cartItems)
                                                    throws javax.script.ScriptException

Caculate bonus from rules and shopping cart items.
從規則與購物品項計算出優惠

Type Parameters:

T - type of real cart item.

Parameters:

rules - Those rules will be applied to caculation.

cartItems - Shopping cart items

Returns:

Bonus from rules and items.

Throws:

javax.script.ScriptException - Error prone when quantity measure from a ILeafRule meet an error.