Java Online

http://www.seas.gwu.edu/~simhaweb/java/

XML API
http://stackoverflow.com/questions/1706493/java-net-malformedurlexception-no-protocol
http://read.pudn.com/downloads144/sourcecode/java/javascript/628647/JavaReadXML/ReplaceChild.java__.htm

Open Source Software in Java
http://java-source.net/

http://marakana.com/bookshelf/java_fundamentals_tutorial/index.html

Java Notes:
http://www.leepoint.net/JavaBasics/index.html

Java Memory Model
http://www.ibm.com/developerworks/library/j-jtp02244/index.html
http://www.cs.umd.edu/~pugh/java/memoryModel/
http://www.cl.cam.ac.uk/~pes20/weakmemory/index.html

http://javarevisited.blogspot.in/

http://howtodoinjava.com/

http://www.learnerstv.com/

http://refcardz.dzone.com/

http://www.javatpoint.com/