SAP HANA Smart Data Streaming interacts with external data sources – for input to the streaming project or output from the streaming project – using Adapters. The role of the adapter is to provide integration with the transport protocol of the source or destination, format the data to convert between the source or destination format and the Smart Data Streaming event record format, and connect to the streaming server.
Smart Data Streaming provides several out of the box adapters that already support many commonly used data sources such a messaging queues, web services, databases, etc. and several common data formats such as CSV, JSON, XML, etc.
In addition to the standard out-of-the-box adapters, Smart Data Streaming also provides an Adapter Toolkit that facilitates building custom adapters that integrate directly into the Smart Data Streaming Development perspective in HANA Studio and which can be managed in the same way as the out-of-the-box adapters that ship with the product. The Adapter Toolkit supports Java and provides a modular approach to building the Transporter and Formatter modules which then work with a pre-built Publish/Subscribe module to make a complete adapter.
You can see a working example of a custom adapter in the tutorial on Writing a Custom Input Adapter for SAP HANA Smart Data Streaming. This tutorial walks you through the process of building a custom adapter to support the MQTT protocol using the Adapter Toolkit.