Automatically section update with java

Hello ,

I have a odt document where I inserted 2 sections from other documents.
Changing these sections requires an update in the enclosing document
when using Libre Office or OpenOffice (popup is asking me).

Does anybody know where and how the "update"-button from LibreOffice (OpenOffice) is
implemented, so that we might reused this functionality programmatically?

I want this document to be updated automatically using some java-code now.
Is there some functionality inside the ODFToolkit or s.th. like that?

Doing it "by hand" using the ODFToolkit is complicated because I have to
merge most of the xml-files (e.g. styles, ..) of these odt documents.

Has anybody experience with such updates?

Is there any information or java snipplet how to effort this?

Thanks for any help, kind regards
Toygun