I actually learned Java first and before C++ (which I am still learning).
If you can handle Java, you can handle C++, depending which type of Java. With Java, it gets easier and lazier, since every new update they make some codes easier, and depending on your instructor, he or she might force you to recognize the old Java scripts, or ignore that fact that it ever existed, as the latest Java has a lot of simple methods that overtake actual knowledge of coding.
All programming will be hard and boring as you program it. The idea in program is ideally the same, so if you cannot handle C++, you probably should not do Java. To me, I think C++ is harder, but I guess it is because I am use to Java; they are similar nonetheless.
If you want to make actual executable programs, learn Visual Basics. With Java, I am still having trouble creating JAR files. Annoying crap.
Check this site out.
All of the computer language share the same type of methods like for loops, if statements, and etcetera; the thing that differs with them is how you call them.