Hello community,
I am a friend of SAP interface programming, it is an exciting area with a lot of possibilities.
Dr. Michael Wegelin and Michael Engelbrecht published the 3rd edition of the book SAP Interface Programming in the SAP Press publishing house, you can find an introduction here. As far as I can see is the actual edition from 2014 only available in German language at the moment.
The book offers different perspectives of interface programming, from the langauges ABAP, C/C++, Java and C#, via RFC, RFC NW library, IDocs, ALE, SOAP and NW Gateway with OData. The description is comprehensive and understandable. It shows a lot of details of the actual programming languages and connection libraries with its possibilities. Though I often have been working in the area of interface programming, this book delivers interesting suggestions for deepening my knowledge. For an introduction or refreshing I can recommend the new edition of this book highly.
Enjoy it.
Cheers
Stefan