Java doesn't "want" you to use ArrayList<Integer>, that's merely more convenient if you need a dynamically sized array and don't want to do the resize yourself.
But the JVM folks are adding support for ArrayList<int> to the language, with the efficiency you'd expect from it.
Value types would hopefully get a big help in terms of getting the JVM GC better once the SDK and popular libraries full utilize it, both by reducing memory pressure and making the heap more GC friendly.
But the JVM folks are adding support for ArrayList<int> to the language, with the efficiency you'd expect from it.