The ebook - http://interactivepython.org/runestone/static/JavaReview-RU/index.html Lots of multiple choice questions, what is on the exam, common mistakes, videos, and practice exams.

Java Visualizer - http://cscircles.cemc.uwaterloo.ca/java_visualize/ Let's you step through Java code and see the values of all of the variables

Java Bat - http://codingbat.com/javaLots of short practice problems in Java. Some of the problems have hints and answers.

Practice It - http://practiceit.cs.washington.eduLots of practice problems in Java.

AP CS A Massive Open Online Course (MOOC) - https://edhesive.com


Alice 3 - http://www.alice.org/index.php
Let's you do drag and drop programming of 3D characters in a 3D world.
How to guide at http://www.alice.org/3.1/materials_guide.php

Greenfoot - http://www.greenfoot.org/door
Makes it easy to create 2D animations and games in Java.