http://www.java2novice.com/jboss/
http://www.journaldev.com/1330/java-collections-interview-questions-and-answers#generics-array
http://www.indiabix.com/
www.tutorialspoint.com/
http://geeksquiz.com/java/inheritance-2/
http://www.javalaunch.com/
http://www.javabeginner.com/
http://www.browxy.com/
http://ideone.com/XPT2Hq
http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b14/java/lang/String.java#String