If you prefer learning from video, and have an O'Reilly subscription, you will find the Java 8 version of my video certification study guide here:
https://learning.oreilly.com/course/oca-java-se/9780134427201/
It's also available for outright purchase from informIT.com, but the O'Reilly subscription is likely better value, even though a rather higher price. Actually, O'Reilly offers a 1 week free trial, which might be sufficient if you really get down to it (just maybe).
Good luck,
Simon