added java workshop link

free-programming-books.md

@@ -932,7 +932,7 @@
 * [Welcome to Java for Python Programmers](http://interactivepython.org/runestone/static/java4python/index.html) - Brad Miller
 * [Introduction to Computer science using Java](http://chortle.ccsu.edu/java5/index.html)
 * [Processing XML with Java (A Guide to SAX, DOM, JDOM, JAXP, and TrAX)](http://www.cafeconleche.org/books/xmljava/) - Elliotte Rusty Harold
-
+* [Welcome to the Java Workshop](http://javaworkshop.sourceforge.net/) - An Apache Project
 
 ####Wicket
 * [Official Free Online Guide for Apache Wicket framework](http://wicket.apache.org/guide/)