Using the Java Class Adapter

The Java Class Adapter cannot be invoked from an input card. The adapter requires data to be passed to it (as defined by a schema) to enable it to determine what to do. There are therefore two scenarios for using the adapter:

• If no data is required to be returned from the adapter: call the adapter in an output card. Typical scenarios include:
  • Creating an object (invoking its constructor, and optionally setting its fields) to be used in a subsequent card.
  • Invoking methods on an object that do not return data. The success of these methods is typically monitored through the use of exceptions.
• Data is required to be returned from the adapter: call the adapter in a GET function call. The approach here is to build the data to be passed to the adapter in an output card, setting the output adapter to sink. Then, in an additional output card, map the root object of this card to the third parameter of the GET using the PACKAGE call to pass the XML data as a text item.