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.

Clam

Answer 1

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

Cheesy

Thanks. But, for using this structure what should I have to do ? Means, is Trove has any .jar file ? – Clam

If you go to the Trove website and go to the "Downloads" section it's pretty straightforward. – Cheesy

Thanks. Actually, I download trove from sourceforge.net/projects/trove4j/files/trove/3.0.1. However, when I add trove.jar file in my class path, it gives error that gnu.trove.set.hash.TIntHashSet (and others) are not found. Can you kindly help me, how to use Trove. – Clam

The trove-3.0.1.jar file is in the lib folder of the zip file. If adding that to your classpath doesn't help, I can't help you. – Cheesy