Do you know a good implementation of a (binary) segment tree in Java?
This has been implemented within the open source Layout Management SW Package project
Here is a link to the sub package
You might find the code useful. I have neither verified it nor run it and I cannot find the license the code is provided under from a quick search of the code and website so Caveat Emptor.
You may be able to contact the authors but the last activity appears to have been August 2008.