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

262 WebSphere Business Integration Adapters

16.3 Performing the verb operation

Most verb operations involve obtaining information from the request business

object. This section provides information about the steps that our doVerbFor()

method takes to process the request business object for each active verb.

16.3.1 Accessing the business object

As part of the Java connector, the doVerbFor() method receives the request

business object as an instance of the CWConnectorBusObj class. To begin verb

processing, the doVerbFor() method needs information from the business object

definition. The CWConnectorBusObj class provides access to the business

object, its business object definition, and attributes. Therefore, a Java

doVerbFor() method does not need to instantiate a separate object for the

business object definition. It can obtain information about the business object

definition directly from the CWConnectorBusObj object passed into doVerbFor().

A business object handler typically uses the business object definition to get

information about its attributes or to get the application-specific information from

the business object definition, attribute, or verb.

Note: For metadata-driven verb processing, the application-specific

information for the verb contains metadata, which provides processing

instructions for the request business object when that particular verb is active.

The getVerbAppText() method is provided by the CWConnectorBusObj class

to obtain application-specific information for the verb of a business object.

Tip: The verb application-specific information can contain the name of the

method to call to process the request business object for that particular verb.

In this case, the doVerbFor() method does not need to branch off the value of

the active verb because the processing information resides in the

application-specific information.

Important: These steps assume that your connector is designed to be

metadata-driven. That is, they describe how to extract application-specific

information from the business object definition and attributes to obtain the

location within the application associated with each attribute. If your connector

is not metadata-driven, you do not need to perform any steps that extract

application-specific information.

Chapter 16. Implementing a business object handler 263

Extracting business object application-specific information

Business objects for metadata-driven connectors are usually designed to have

application-specific information about the application structure. For such

connectors, the first step in a typical verb operation is to retrieve the

application-specific information from the business object definition associated

with the request business object. The Java connector library provides the

following methods to retrieve application-specific information from the business

object definition:

 The getAppText() method, with no arguments, returns the

application-specific information as a Java string. It can also retrieve the value

of a specified name-value pair within the business object level

application-specific information.

 The getBusObjASIHashtable() method returns the application-specific

information as a Java hash table of name-value pairs.

Accessing the attributes

The connector can use attribute methods in the CWConnectorBusObj class to

obtain information about an attribute, such as its cardinality or maximum length.

Methods that access attribute properties provide the ability to access an attribute

in the following ways:

 Attribute name

You can identify the attribute by its Name property to obtain its attribute

object.

 Integer index

To obtain the attribute index (its ordinal position), you can:

– Obtain a count of all attributes in the business object definition with

getAttrCount() and loop through them one at a time, passing each index

value to one of its attribute-access methods

– Obtain the index for a particular attribute by specifying its name to

getAttrIndex().

Note: Both the getAttrCount() and getAttrIndex() methods are defined

in the CWConnectorBusObj class.