A GeneralPath object contains Shapes and is itself a Shape.
Would this be an example of a class that uses the Composite Pattern?
I am confused by the Composite Pattern condition: "Clients treat a composite object as a primitive object."
Is this use of primitive different from a primitive data type (i.e. int) ?
Yes this is an example of that "pattern" (I hate the term "pattern" for more reasons than I can possibly get into in this post).
I presume you're reading from Horstmann. You are confused because "primitive" in that context means something different than "primitive" in the Java context you are comparing it to.
Clients treat a composite object as a primitive object.
In the above context, "primitive" means the root object itself, i.e., in your case, a Shape.
[Java] primitive data type (i.e. int)
In the above context, "primitive" refers to, of course, a Java primitive data type, e.g. int or boolean.
Same word, different context, different meanings.