Working with Lists in SAP HANA Cloud Integration

  • by Dr. Volker Stiehl, Professor, Ingolstadt Technical University of Applied Sciences
  • February 16, 2016
Volker Stiehl shows how to use SAP HANA Cloud Integration (SAP HCI) to model the handling of messages containing a list of entries. You apply the Splitter and the Gather steps in your integration flow to iterate over the individual items of the list, retrieve additional data for each line item, and collect the results back into one aggregated response message.
Learning Objectives

By reading this article you will:

  • Know how to apply list handling in your SAP HANA Cloud Integration (SAP HCI)-based scenarios
  • Understand what is necessary to configure the Splitter and Gather steps in your message processing chain correctly
  • Learn how Splitter and Gather form a pair and how all the steps in between the pair are executed for every single item (iteration over the list)
  • Understand how the Splitter/Gather pattern can be used to enrich each single list item with data coming from an external data source
Key Concept

Every major integration project requires functionality to work on messages containing lists of entries. Integration solutions such as SAP HANA Cloud Integration (SAP HCI) must provide features to iterate over a list and handle each list item individually.

In my recent articles about SAP HANA Cloud Integration (SAP HCI), you learned a lot about SAP HCI’s functionality, the basic concepts behind it, and different modeling techniques for solving typical integration problems such as message enrichment, message mapping, and message routing. However, in the examples so far, I focused on the handling of messages containing just one item, a single order, for example. Now I dive into the details of coping with messages comprising a list of entries, such as how to:

  • Split up such a message into individual pieces
  • Iterate over each list item
  • Handle the resulting single messages in an SAP HCI message processing chain
  • Combine the results of each single message handling sequence back into one response message

The Scenario

In real-life scenarios integrators are quite frequently confronted with input messages consisting of several items of the same message structure grouped in a list (e.g., order line items). The integrator wants to iterate over the list. Individual list items have to be separated and individually managed by the integration flow. Finally, the result of each individual message handling procedure needs to be consolidated into one response message being sent to either the sender of the message (in case of a synchronous scenario) or to the final recipient (in case of an asynchronous scenario).

Dr. Volker Stiehl

Prof. Dr. Volker Stiehl studied computer science at the Friedrich-Alexander-University of Erlangen-Nuremberg. After 12 years as a developer and senior system architect at Siemens, he joined SAP in 2004. As chief product expert, Volker was responsible for the success of the products SAP Process Orchestration, SAP Process Integration, and SAP HANA Cloud Integration (now SAP HANA Cloud Platform, integration service). He left SAP in 2016 and accepted a position as professor at the Ingolstadt Technical University of Applied Sciences where he is currently teaching business information systems. In September 2011, Volker received his Ph.D. degree from the University of Technology Darmstadt. His thesis was on the systematic design and implementation of applications using BPMN. Volker is also the author of Process-Driven Applications with BPMN as well as the co-author of SAP HANA Cloud Integration and a regular speaker at various national and international conferences.

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