The easiest thing to do is download and install the OSX package that is provided on openCollabNet. This installs Subversion, including the JavaHL library, into /opt/subversion. It then makes a symlink for the JavaHL library into /Library/Java/Extensions. This is a global location that the OSX JVM looks in when loading libraries via JNI. So basically, if you install this package, there is nothing else you need to do. It is OK to install this after you have installed Subclipse.