Reference links and book marks

Volatile
http://www.javamex.com/tutorials/synchronization_volatile_java_5.shtml

New features of Java5
http://docs.oracle.com/javase/1.5.0/docs/relnotes/features.html
http://courses.coreservlets.com/Course-Materials/pdf/java5/23-Java5-Features.pdf

JavaConcurrency
http://www.vogella.com/articles/JavaConcurrency/article.html

Design Patterns
http://www.oodesign.com
http://www.avajava.com/tutorials/lessons/factory-pattern.html
http://www.avajava.com/tutorials/lessons/abstract-factory-pattern.html
http://javarevisited.blogspot.in/2011/03/10-interview-questions-on-singleton.html

http://helpx.adobe.com/cq/kb/TakeThreadDump.html