Addtional repositories with code and samples:

https://bitbucket.org/symentis/shoppy-java - demo application used for exercises during trainings, wicket+spring+JPA, works under Jetty, Tomcat and Wildfly

https://bitbucket.org/kcrimson/jvm-internals - lots about bytecode and generation, not so much about remaning stuff, maybe someday, but it is still usefull