Java Hash Multi Map (key with multiple values) Implementation

Question

From here , I found that Colt's OpenIntIntHashMap and Trove's TIntIntHashMap give better performance and memory uses than Java's built in HashMap or Guava's HashMultimap .

Do Colt's OpenIntIntHashMap or Trove's TIntIntHashMap allow keys with multiple values, as with HashMultimap ? If not what is a nice way to implement a HashMultimap that can achieve Colt's or Trove's performance and memory efficiency?

Note: I have tested Guava's HashMultimap , but its performance and memory efficiency seems poor to me.

Answer 1

Multimaps.newSetMultimap(
  TDecorators.wrap(new TIntObjectHashMap<Collection<Integer>>()),
  new Supplier<Set<Integer>>() {
    public Set<Integer> get() {
      return TDecorators.wrap(new TIntHashSet());
    }
  });