Hello and welcome to JME
Please note, JMonkeyEngine is updated all the time(recently in 3.3 all animation system were changed), but most of the code is unchanged, so this old tutorials should still work.
Anyway if you want, you can always search topics on this forum to see most recent if you got any issues. if there are none, then just write a new one if its JME related.
Also, some of us, might not even know if some of tutorials from:
have some outdated code/text, if so, then please report, because new users who read it should report if anything is wrong to let know. (if someone miss change it while doing engine change)
about general Java learning, then there are a lot of learn sources i think. myself even before i study if, i learned it myself. true is, if someone really want to learn, he can learn it using every possible source.
if you will need to know how all of JME work, you have sourcecode of it.
JME in general use LWJOGL(its a java wrapper for opengl) it use JNI(one of java interfaces) that allow executing C funcions via Java methods. its quite easy if you know C.
also one quick tip:
if you gonna use own selected jars. then please note:
some of packages(jars) should not be included. for example “dont include jme-bullet-android when you dont use android” and “dont use jme-bullet-native if you use android”