How can i use my libxpcom.so to install Java

Hi, i'd like to install the BlackdownJavaJRE. But it depends on installing a libxpcom.so. With `pin libxpcom.so` i learned that it is a file from Mozilla. I don't want to install a complete Mozilla for installing Java. In the directory of my Firebird i found a libxpcom.so. How can i integrate this file to my system, so that rpm will find it? thx