Although both are object oriented programming language and Java was derived from C++ but still there is big difference between these two languages.
You can see the actual difference once you start programming on it.
But here i am going to give you few differences between these two...
Java does not support operator overloading
A class definition in Java looks similar to a class definition in C++, but there is no closing semicolon.
Forward reference declarations are not required in Java.
Scope resolution operator (::) required in C++ is but not in Java.
In C++ you have to re-declare static data members outside the class but such things are not required in Java.
java does not use destructor.