java was part of Open Office which ceased to function. Is open office dead?
What’s your question? Java was never a part of OpenOffice, but OpenOffice needs Java for some of its functionality. OpenOffice is still alive, but development is very slow.
Questions specifically concerning OpenOffice (Apache OO now) may be even more likely to get a useful anwer soon if posted to https://forum.openoffice.org/en.
That forum is well structured and supports a hierarchical search…
Java support on Windows is not a problem at all. However, since OpenOffice for Windows still is 32 bit, you also need the Java (JRE / SDK) for 32 bit if your OpenOffice shall use it.
To have more than one Java on your system is not a problem again. Just point to the correct one in the AOO options.
Note that this answer does not apply to 64-bit LibreOffice.