Patterns: Implementing Self-Service in an SOA Environment

394 Patterns: Implementing Self-Service in an SOA Environment

12.2.2 Object model

In this section, we provide an object model for our JCA scenario.

Class diagram

Figure 12-4 on page 394 shows a class diagram for the JCAModule portion of

the application. We focus on this piece because it provides the actual interface to

the back-end CRM system. The diagram shows the static relationships between

the classes.

MartAccounts and MartJ2CBeanImpl were developed for the ITSOMart

application. The rest of the classes are provided by the ECI resource adapter or

the J2EE packages.

Figure 12-4 Class diagram for J2EE Connector scenario

The com.ibm.patterns.jcaService package includes MartJ2CBeanImpl which

uses MartAccounts to update a customer record in the enterprise tier.

Chapter 12. J2EE Connector Architecture scenario 395

The MartAccounts class provides a byte array for the CICS COMMAREA, which

is used to pass the information to the back-end application. The MartAccounts

class is an implementation of the Record class provided by J2EE Connector

class library.

The ECIInteractionSpec class is the specification of an interaction for CICS ECI.

The superclass of ECIInteractionSpec is InteractionSpec. The various kinds of

resource adapters extend InteractionSpec.

InteractionSpec and Record are the only classes that need to be specific to a

particular resource adapter. If an application needs to interact with another

resource adapter, the only changes that need to be made are to use the new

Record class and InteractionSpec class. The use of the other classes, such as

ConnectionFactory, Connection, and Interaction, remains the same. For

example, if the application needs to have an interface with the IMS Resource

adapter, the application needs a new Record for IMS and it needs to create and

set an IMS InteractionSpec, which is passed to the generic interaction object.

Interaction diagram

The interaction diagram in Figure 12-5 shows the sequence of the message flow

for the JCA call within the ITSOMart application. Once the customer credit rating

is checked, the customer registration information is sent to the CRM application

and an e-mail is sent to the customer.

Figure 12-5 Interaction diagram for JCA functionality in ITSOMart scenario

Figure 12-6 on page 396 shows the message interactions of the classes.

396 Patterns: Implementing Self-Service in an SOA Environment

Figure 12-6 Sequence diagram for createCustomerJ2EE Connector scenario

1) Processor invokes the storeCustomerDetails_CICS() method of

ProcessorJCA.

2) ProcessorJCA invokes the createMartAccount_CICS method of

JCAWSClientBean to create the customer with the information

provided in CustomerDetails object.

2.1) JCAWSClientBean invokes the createCustomer() method of

MartJ2CBeanImplProxy.

2.1.1) MartJ2CBeanImplProxy invokes the createCustomer() method of

MartJ2CBeanImpl.

2.1.1.1) MartJ2CBeanImpl gets a connection using a connection factory. The

runtime connection attributes are configured from the application

server connection factory properties. This may not mean a physical

connection to the enterprise has been opened. A physical connection

c

:MartJ2CBeanImp/Proxy

self:Processor

c

I

:ConnectionFactory

c

:ProcessorJCA

c

:JCAWSClientBean

c

:MartAccounts

c

:MartJ2CBeanImpl

I

:Connection

I

:Interaction

I

:Record

c

:ECIInteractionSpec

1: storeCustomerDetails_CICS

2: createMartAccount_CICS

2.1: createCustomer

2.1.1: createCustomer

2.1.1.1: getConnection

2.1.1.2: createInteraction

2.1.1.2.1: \CalledOperation\

2.1.1.3: ECIInteractionSpec

2.1.1.4: setCommareaLength

2.1.1.5: setReplyLength

2.1.1.6: setFunctionName

2.1.1.7: setInteractionVerb

2.1.1.8: \CalledOperation\

2.1.1.9: execute

2.1.1.10: \CalledOperation\

2.1.1.12: close

2.1.1.13: close

2.1.1.11: \CalledOperation\

<<return>>

2.1.2: createCustomer

<<return>>

3: createMartAccount_CICS

<<return>>

Web Service:

<<return>>

2.2: createCustomer