Question

I know LinkedHashMap has a predictable iteration order (insertion order). Does the Set returned by LinkedHashMap.keySet() and the Collection returned by LinkedHashMap.values() also maintain this order?

Answer 1

The Map interface provides three
collection views, which allow a map’s contents to be viewed as a set
of keys, collection of values, or set
of key-value mappings. The order of
a map is defined as the order in which
the iterators on the map’s collection
views return their elements. Some map
implementations, like the TreeMap
class, make specific guarantees as to
their order; others, like the
HashMap class, do not.

— Map

This linked list defines the iteration
ordering, which is normally the order
in which keys were inserted into the
map (insertion-order).

— LinkedHashMap

So, yes, keySet(), values(), and entrySet() (the three collection views mentioned) return values in the order the internal linked list uses. And yes, the JavaDoc for Map and LinkedHashMap guarantee it.

That is the point of this class, after all.