No one can answer that because we probably don't know the course. Java's HUGE... I've been a professional programmer for 30 years and been using Java since the 1st beta. I worked on JVM code at Sun/Oracle also wrote one myself. Did practically everything in the Java realm...
I don't know all there is to know in Java.
Our profession is based on learning, adapting and understanding the depth of your own ignorance. When you start getting a sense of your lack of knowledge and how deep that hole is... That's the interesting part.