1. Customizing the way percent discount engine works:
   1. Implement a new DiscountEngine by extending the abstract class DiscountEngine (com.vmops.component.discount.policy.DiscountEngine) and put it inside the citrix.cpbm.custom bundle.
   2. Edit the cloud.properties at /usr/share/vts3/repository/prop to point to the new entry by editing the property discount.percent.engine.implementation. Point it to the new implementation.
2. Customizing the way amount discount engine works:
   1. Implement a new DiscountEngine by extending the abstract class DiscountEngine (com.vmops.component.discount.policy.DiscountEngine) and put it inside the citrix.cpbm.custom bundle.
   2. Edit the cloud.properties at /usr/share/vts3/repository/prop to point to the new entry by editing the property discount.amount.engine.implementation. Point it to the new implementation.
3. Customizing the way non promotional discount engine works:
   1. Implement a new DiscountEngine by extending the abstract class DiscountEngine (com.vmops.component.discount.policy.DiscountEngine) and put it inside the citrix.cpbm.custom bundle.
   2. Edit the cloud.properties at /usr/share/vts3/repository/prop to point to the new entry by editing the property discount.adhoc.engine.implementation. Point it to the new implementation.

   Restart the CPBM service.

1. Implement a new DiscountEngine by extending the abstract class DiscountEngine (com.vmops.component.discount.policy.DiscountEngine) and put it inside the citrix.cpbm.custom bundle.

2. Add one or more such implementations.

3. Open the application context file applicationContext-admin-customizations.xml inside the citrix.cpbm.custom bundle.

   Define a bean for each implementation:

   <bean name="discountEngineCustom" class="<Newly added class>" />

   Add the above created bean to the list 'taxEngineList':

   <bean id="discountEngineList" class="java.util.ArrayList">  		<constructor-arg>  			<list>  				<ref bean="adhocDiscountEngine" />  				<ref bean="percentDiscountEngine" />  				<ref bean="amountDiscountEngine" />  				<ref bean="discountEngineCustom" />  			</list>  		</constructor-arg>  	</bean>

   or

   <bean id="taxEngineList" class="java.util.ArrayList">  		<constructor-arg>  			<list>  				<ref bean="discountEngineCustom" />  			</list>  		</constructor-arg>  	</bean>

   Note: You can remove the default implementation and/or add multiple such beans in the list. Beans will be called in the same order as defined in the list.

4. Restart the CPBM service.

public interface RateAdjuster {      /**     * @param invoice A read only (not enforced) invoice for the rate adjuster to get info related to this invoice such as     *          tenant, billing period etc.     * @param newInvoiceItems Every RateAdjuster should process the newInvoiceItems and replace them with adjusted items     *          for the next adjusters for further processing. The first adjuster sees the invoiceItems of     *          ChargeType.CHARGE     * @param serviceStart is the billing period start for the moment, it can be any day in the billing period if we     *          decided to support number of days for a promotion (as oppose to number of billing period)     * @param serviceEnd is the billing period end for the moment, it can be any day in the billing period if we decided     *          to support number of days for a promotion (as oppose to number of billing period)     * @param previewMode if true, nothing will be written to db or the billing activity file. Plan to remove this soon.     * @return     */      public abstract BigDecimal compute(Invoice invoice, List<InvoiceItem> invoiceItemsToBeProcessed, Date serviceStart,        Date serviceEnd, boolean previewMode);    }  

public class ExampleDiscountEngine extends DiscountEngine {      @Override    public BigDecimal compute(Invoice invoice, List<InvoiceItem> invoiceItemsToBeProcessed, Date serviceStart,        Date serviceEnd, boolean previewMode) {      …… [Put your implementation here ]  }  }