How to eliminate duplicates in Guava MultiMap values?

Question

Code:

    Multimap<String, String> myMultimap = ArrayListMultimap.create();     myMultimap.put("12345", "qwer");     myMultimap.put("12345", "abcd");     myMultimap.put("12345", "qwer");     System.out.println(myMultimap); 

Result:

{12345=[qwer, abcd, qwer]} 

Is it possible to eliminate duplicate "qwer" ? Thanks.

Answer 1

Use one of the SetMultimap implementations, for example HashMultimap:

SetMultimap<String, String> myMultimap = HashMultimap.create(); myMultimap.put("12345", "qwer"); myMultimap.put("12345", "abcd"); myMultimap.put("12345", "qwer"); System.out.println(myMultimap); // {12345=[abcd, qwer]} 

Answer 2

A ListMultimap such as ArrayListMultimap allows duplicate key-value pairs. Try an implementation of SetMultimap such as HashMultimap or TreeMultimap.