I completly disagree with GuardianX
The difference between Java and C++ is mainly that C++ is the mighty mother (to be exact it is C but C++ is the better C) of nearly all popular languages out there. There is nearly nothing you can't do with C++, it even inherits most new language technologies from other languages.
However that makes C++ very heavy, redundant, repetetive and complicated. There are 4 (or 5?) ways to initialize a variable while the language itself lacks of newer innovations like from Java and C#. It is years behind.
Your case really cries for Java!
Advantages
1. It is nearly as fast (in some cases even faster) then C++
2. It is a very intelligent and fast to write language and propably one of the most innovative ones
3. It is purely designed to write code fast, efficient and fail safe
4. It has a lot of libraries.
5. When reading the C++ documentary you are going to read something like this very often "This action can be very dangerous and can have unpredictable results" - not in Java, completly fail safe.
6. If an coding error happens in Java during runtime or when compiling you are always told exactly where the error happend, what happened and why.
This is not the case in C++, it makes you often really search for the error and the hints it gives you are not always correct. It is not bad but in comparison to Java it lacks a lot.
7. It has features like auto-import. If you want to use a library in C++ you have to manually write it on top of your code, in Java it automatically imports those functions.
This saves a lot of time and performance. Also other auto-completion tools
(I have no idea why this doesn't exist in C++)
8. Java has great IDEs like Eclipse or IntelliJ with millions of plugins. Eclipse is also available for C++.
C++ has VisualStudio, crappy, slow, little bit buggy software with a lack of proper tools.
9. The Java compiler is REALLY fast. C++ needs a while to compile. So for testing purposes you can just alter a variable and start your program over and over again to see what happens.
I don't want to start talking about C++ in this matter but it gets really painful there.
10. Java as well as C++ can be used on nearly every platform. However Java is not available for IPhones.
When coding carefully with C++ you can compile it nearly with no code corrections for other systems.
In Java you can just run your already compiled program on every machine, though porting between Android and PC is not possible due to a different VirtualMachine (Java and Dalvik).
There are many more advantages of Java over C++ but I risk repeating myself, so I say it one last time:
Java is a fast coding language due to it's automatic tools, intelligent fast compilers, intelligent overall languages, it is fail safe and you have a lot of auto-imported libraries at your service.
It is also very good and fail safe when coding in a team.
Disadvantages
1. No Unity, a powerful game engine. There are of course Java Android game engines, but Unity is outstanding from all free engines out there.
2. If you learn Java first, it is really hard to learn C++ as you have to "reduce your life standards" because of the reasons above. It is easier to learn C++ first and then change to Java, because both languages share nearly the same syntax and Java is a lot easier then C++. When learning Java first and then C++ you are going to think the words "WHY THE HELL DO I NEED TO DO THIS!!?!?" very often.
3. Java is strictly(!) OOP. This is actually an advantage because the language is forcing you to a specific, strict and clean coding architecture which is also an advantage when coding together with others, however it can be an obstacle for beginners to OOP to understand the concept and design their code in this direction.
C++ 'supports' OOP, however It lets you circumvent the restrictions which leads to bad code but you don't need to start from scratch or recode big architectural decisions made before because you planned in some design decisions or features which were thought of later in development.
So you are basically crying for Java! "Just to make games".