I think this will be a cool API that enable developer to use openoffice at their code. However there is not much tutorial / guide. Here are 2 I known

http://technology.amis.nl/blog/?p=1243
http://technology.amis.nl/blog/?p=1244

Other than that, Lotus release an eclipse base Office suit recently, we suppose able to program using this, if there is no obfuscation - http://symphony.lotus.com/software/lotus/symphony/home.jspa

Generate Graph directly - http://www.programming-free.com/2012/12/create-charts-in-excel-using-java.html

Alternative to POI, jXLS - http://fahdshariff.blogspot.com.au/2014/06/parsing-excel-file-into-javabeans-using.html

Using POI to update MS Word document - http://www.infoq.com/articles/convert-microsoft-word-to-html