Demeter/Java allows you to use all features of Java.
The tools themselves currently
use JAR (for distribution) and Reflection (for implementing around methods).
Java features we use (See JDK Guide to new features) . There you can learn about JAR, Reflection and also about RMI and JavaBeans which we will use.
For example, http://java.sun.com/products/jdk/1.1/docs/guide/jar/index.html tells you about JAR.
Demeter/Java makes extensive use of JavaCC:
Java Compiler Compiler Home page (for look-ahead concept and notation)
The implementation of APPCs uses JavaBeans. JavaBeans information (for event-based implementation of APPCs)