Hello,
das hat nicht was mit den APIs auf der AS/400 zu tun? Nö, oder?
Soweit ich die Zusammenhänge sehe, ist da immer die Rede von Notes/Domino und Java und Excel Worksheets die Rede.

Why POI?
It is a much lamented fact that it's difficult to interoperate with Microsoft's proprietary file formats.
The Apache Software Foundation has answered this problem with a project known as POI (POI stands for Poor Obfuscation Implementation).
The goal of POI is to make Microsoft Office files based on Microsoft's OLE 2 Compound Document format easy to manipulate through a set of Java APIs.
POI APIs have been developed for only the most common Microsoft Office files, Word and Excel; other APIs exist for general OLE 2 Compound Documents and property files.
The Apache POI website at http://jakarta.apache.org/poi/index.html can provide you with a wealth of additional information about the POI project and these APIs.