WebSphere Business Integration Adapters: An Adapter Development and WebSphere Business Integration Solution

256 WebSphere Business Integration Adapters

16.1 Extending the business-object-handler base class

In the Java connector library, the base class for a business object handler is

named CWConnectorBOHandler. The CWConnectorBOHandler class provides

methods for defining and accessing a business object handler. To implement

your own business object handler, extend this business-object-handler base

class to create your own business-object-handler class.

To derive a business-object-handler class for a Java connector, do the following:

1. Create a class that extends the CWConnectorBOHandler class, and name

this class as follows:

connectorNameBOHandler.java

Let connectorName uniquely identify the application or technology with which

the connector communicates. For example, to create a business object

handler for the RedMaintenance application, create a business object handler

class called RMBOHandler. If your connector design implements multiple

business object handlers, include the name of the business objects in the

name of the business object handler class.

2. Implement the doVerbFor() method to define the behavior of the business

object handler.

The following example shows the basic structure of our class:

Example 16-1 Basic structure of the out custom business object

public class RMBOHandler extends CWConnectorBOHandler {

public int doVerbFor(CWConnectorBusObj bo)

throws ConnectionFailureException, VerbProcessingFailedException {

}

}

16.2 Implementing the doVerbFor() method

The doVerbFor() method provides the functionality for the business object

handler. When the Adapter Framework receives a request business object, it

calls the doVerbFor() method for the appropriate business object handler to

perform the action of this verb. For a Java connector, the

CWConnectorBOHandler class defines the doVerbFor() method in which you

define the verb processing.

However, the actual doVerbFor() method that the Adapter Framework invokes is

the low-level version, which the CWConnectorBOHandler class inherits from the

Chapter 16. Implementing a business object handler 257

BOHandlerBase class of the low-level Java connector library. This low-level

doVerbFor() method calls the user-implemented doVerbFor() method.

Therefore, as part of the business-object-handler class (an extension of

CWConnectorBOHandler), you must provide an implementation of the

doVerbFor() method.

The business object handler:

1. Receives business objects from the Adapter Framework.

2. Processes each business object based on the active verb.

3. Sends requests for operations to the application.

4. Returns status to the Adapter Framework.

16.2.1 Obtaining the active verb

To determine which actions to take, the doVerbFor() method must first retrieve

the verb from the business object that it receives as an argument. This incoming

business object is called the

request business object. The verb that this business

object contains is the

active verb, which must be one of the verbs that the

business object definition supports.

Obtaining the active verb from the request business object generally involves the

following steps:

1. Verifying that the request business object is valid.

Before the connector calls the getVerb() method, it verifies that the incoming

request business object is not null. The incoming business object is passed

into the doVerbFor() method as a CWConnectorBusObj object.

2. Obtaining the active verb with the getVerb() method.

After the request business object is validated, you can use the getVerb()

method that is inherited from the CWConnectorBusObj class to obtain the

active verb from this business object.

Note: Java connectors must be thread-safe. For Java connectors, the Adapter

Framework uses separate threads to call into the doVerbFor() method.

Important: If the business integration system uses InterChange Server and

collaborations are coded to be multi-threaded, the Adapter Framework might

call into the doVerbFor() method with multiple threads representing request

processing.