IMS Connectivity in an On Demand Environment: A Practical Guide to IMS Connectivity

232 IMS Connectivity in an On Demand Environment: A Practical Guide to IMS Connectivity

12.3 Building applications that use IMS Connector for Java

Applications that use IMS Connector for Java can be built in different ways:

 Using the tools provided with IBM WebSphere Studio Application Developer Integration

Edition Version 5.1

These tools generate applications that are based on an enterprise service that represents

the IMS transaction. The generated application uses Web Services Invocation Framework

(WSIF). The tools also use WSIF. The tools also generate Format Handler classes to aid

in the conversion of IMS transaction input and output messages.

 Using the tools provided with IBM Rational Application Developer V6

Rational Application Developer tools generate applications that are based on a JCA Java

bean that represents the IMS transaction. Java data bindings for the input and output

message of the IMS transaction are generated separately.

 Coding directly to the CCI provided by the IMS resource adapter

For this option, the user has the option of using WebSphere Studio Application Developer

Integration Edition or Rational Application Developer to generate classes to process the

input and output messages of the IMS transaction.

We give examples of all three types of applications and explain how to build them. All three

solutions use the CCI. In the case of WebSphere Studio Application Developer Integration

Edition and Rational Application Developer, the CCI is used by the generated code.

12.3.1 Introduction

As already outlined, each execution of a transaction in IMS requires two basic steps:

 Connection: To IMS through IMS Connect

Connections can be reused by several connector clients if they are managed with

connection pooling or a connection handler obtained in one particular client is reused for

several Interactions.

Connection characteristics are determined by the properties of the ConnectionFactory and

the ConnectionSpec instances used during the getConnection method.

 Interaction: With an IMS transaction (conversational or non-conversational)

Interaction characteristics are determined by the properties of the InteractionSpec

instance provided when the execute method of the Interaction instance is invoked. In

addition, Input and Output objects are specified during the invocation of the call.

IMS Connector for Java allows for many options in its connection and interaction. These

options are specified as properties of objects provided at run time.

In the next section, we describe the different options that influence the behavior of your

application.

12.3.2 Connection properties

The characteristics or properties of a connection are determined when the connection is

acquired. They are obtained mainly from two sources:

 IMSConnectionFactory

You should remember that this item can be described as a JNDI reachable object from a

namespace from which it can be looked up or through the instantiation of an

IMSManagedConnectionFactory from which an IMSConnectionFactory can be created.