I am using the Lobo - Java Web Browser library, and it gives me an exception which after some research I determined could be due to the library having been complied against
The lobobrowser project is dead, but some nice user comittet a patch to fix your problem:
http://sourceforge.net/tracker/?func=detail&aid=2991043&group_id=139023&atid=742262
Since a dead project doesn't release any patched jars, I did it ;-) Find a cobra-gp-0.98.5.jar with the above patch applied at : http://www.wikisquare.de/public/cobra-gp-0.98.5.jar
javax.swing.text.StyleContext.getDefaultStyleContext.getFont might work for you, across JDK releases.
See further http://elliotth.blogspot.com.au/2007/04/far-east-asian-fonts-with-java-7-on.html
I think 'sun.font.FontManager'was removed with Java7, so if you must use it (I'd recommend against it and look for another package instead) you could try running it with java6.