Java Development Focused on Enterprise Use

Forrester Research cited by PCWorld Business Center predicts that Java will become a specialized server-side language for Oracle and IBM enterprise customers. I think so too, and that will only just increase the demand for Java programmers!
Forrester: Oracle Confining Java Future to Enterprise Use

Free Online SQL Tests and Tutorials

SQL Tutorial
Interactive SQL tutorial (SQLzoo.net)
SQL Quick Reference
Database Normalization Basics

http://www.geekinterview.com/quiz/SQLQuiz.html
Oracle specific, includes questions about SQL Plus commands.

http://www.wiziq.com/tests/sql
Mostly Oracle specific, need to sign up to see your score.

http://www.sqlquiz.com/
Very good!
After taking the test you get a report with your time, your score, your answer for each question, if this is correct or not, and recommended reading for incorrect answers.

http://tools.people-centric.ro/index.php?option=com_otests&view=order

http://www.w3schools.com/sql/sql_quiz.asp
20 questions, no time limit, at the end of the Quiz, your total score will be displayed.

Python vs. Java ?

"Python is a high-level programming language suitable for simple tasks, as well as for learning computer algorithms and programming main functions." José Braga de Vasconcelos - The Official Association for Computing Machinery (ACM) Group on LinkedIn

Oracle ADF Certification

 http://education.oracle.com/pls/web_prod-plq-dad/db_pages.getpage?page_id=41&p_org_id=54&lang=RO&p_exam_id=1Z0_554

Sources for answers:

http://www.techrepublic.com/blog/programming-and-development/learning-oracle-adf-creating-java-objects-from-database-tables/466

http://www.techrepublic.com/blog/programming-and-development/learning-oracle-adf-simple-jsf-data-viewentry-form/476?tag=rbxccnbtr1

http://www.techrepublic.com/blog/programming-and-development/learning-oracle-adf-master-detail-forms/492?tag=rbxccnbtr1

http://adfhowto.blogspot.com/2010/12/possible-adf-interview-questions.html

http://blogs.oracle.com/workingwithadf/