com.caucho.jsp.JspParseException: Resin can't load 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 or jikes. java.lang.ClassNotFoundException: sun.tools.javac.Main