Resin can't load com.sun.tools.javac.Main

Resin can't load com.sun.tools.javac.Main.  Usually this means that the 
JDK tools.jar is missing from the classpath, possibly because of using 
a JRE instead of the JDK.  You can either add tools.jar to the classpath 
or change the compiler to an external one with <java compiler='javac'/> 
or jikes. 

http://www.wozaishuo.com.cn/article.asp?id=258

http://www.chedong.com/tech/resin.html