In Java, the value of the variable of a class type is not an object - it's a reference to the object. Those references are always stack-allocated. Variables of primitive types like ints are also, of course, stack allocated.

In Go, if you have a local of type int, and that local is captured by a closure, it will be allocated on the heap to extend its lifetime. Java doesn't need to do this because it requires captures to be effectively final. On the other hand, C# does the same thing as Go.