How detailed do I have to provide sources I am currently writing my master thesis and I am extremely insecure where and when to give the sources. I tried to google for any recommendations but could not find anything that helps me.

How often do I need to give the source for information when it belongs to the same topic and I introduced the one and only document to this topic already? 

For example I am referring to a technical standard and when introducing this standard I give reference to its standard document. Now I will give more information later on on this standard as I compare it to other standards. Do I repeat to mention the standard document? Since this document is quite long: Do I have to exactly say where in that document I found the information?

EDIT:
Also while we at it: I also give information about a the Java programming language. Can I assume that everyone knows this? Especially since it's the teaching language, the most widely spread language used in industry, most probably all my readers know it and it is very easy find out about this language if not. Do I still need to give the source for my information?
When you first introduce the technical standard in your thesis, you should provide citations to any and all relevant documents.  By "any and all", I mean the set that you are making use of directly, but not previous versions, commentary, or ancillary documents.  Each reference should appear separately in your Bibliography.

After that, you do not need to provide additional citations even when you refer to that technical standard later in the same chapter, or in later chapters.  However, if you are quoting text from the standard, or otherwise you are analyzing/critiquing the standard in detail, then it would be helpful to your readers to provide citations to the specific reference and page numbers.  Sometimes, depending upon the standard, it is more appropriate to cite chapter, section, and subsection numbers.  You say that you are comparing different technical standards.  If so, then it would be very appropriate to provide chapter, section, and subsection numbers for the respective standard sections.  Somewhere on the page (e.g. footnotes) you could provide citation to the technical standard document(s) themselves.