Why it is possible to create collection of array of primitives but not collection of primitives

Question

Java does not support creating a collection out of primitives, so following construct gives compilation error ("The argument can not be of primitive type):

 List<int> ints = new ArrayList<int>(); 

On the other hand creating a collection of arrays or primitives is allowed, so following construct is ok:

List<int[]> ints = new ArrayList<int[]>();

What is a logic behind this?

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Edit: The question is really about the array of primitives, not the primitives, so please don't explain me why can't I store primitives in collection, but rather why can I story array of primitives inside a collection?

Answer 1

Collections are generic: Collection<T>. T must be reference type. Primitives aren't reference types. On the other hand, array of primitives is a reference type so you can put it to Collection. Remember, that every primitive has it's wrapper class which can be passed as a type to generic type.

According to the specification:

Type:
    PrimitiveType
    ReferenceType

A class is generic if it declares one or more type variables (§4.4).

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4.3.1. Objects An object is a class instance or an array.

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4.4. Type Variables A type variable is an unqualified identifier used as a type in class, interface, method, and constructor bodies.