package com.apress.springrecipes.jbpm.jbpm4.customers;
public interface CustomerService {
void sendWelcomeEmail(Long customerId);
void deauthorizeCustomer(Long customerId);
void authorizeCustomer(Long customerId);
Customer getCustomerById(Long customerId);
Customer createCustomer(String email, String password, String firstName, 
String lastName);
void sendCustomerVerificationEmail(Long customerId);
}

<?xml version="1.0" encoding="UTF-8"?>
<process name="RegisterCustomer" xmlns="http://jbpm.org/4.0/jpdl">
          <start>
          <transition to="send-verification-email" />
          </start>
          <java name="send-verification-email" expr="#{customerService}"
          method="sendCustomerVerificationEmail">
          <arg> <object expr="#{customerId}" /> </arg>
          <transition to="confirm-receipt-of-verification-email" />
          </java>
          <state name="confirm-receipt-of-verification-email">
          <transition to="send-welcome-email" />
          </state>
          <java name="send-welcome-email"
          expr="#{customerService}" method="sendWelcomeEmail">
          <arg> <object expr="#{customerId}" /> </arg>
          </java>
</process>

<?xml version="1.0" encoding="UTF-8"?>
<process name="RegisterCustomer" xmlns="http://jbpm.org/4.0/jpdl">
          <start>
          <transition to="send-verification-email" />
          </start>
          <java name="send-verification-email" expr="#{customerService}"
          method="sendCustomerVerificationEmail">
          <arg> <object expr="#{customerId}" /> </arg>
          <transition to="confirm-receipt-of-verification-email" />
          </java>
          <state name="confirm-receipt-of-verification-email">
          <transition to="send-welcome-email" />
          </state>
          <java name="send-welcome-email"
          expr="#{customerService}" method="sendWelcomeEmail">
          <arg> <object expr="#{customerId}" /> </arg>
          </java>
</process>