I just noticed this unexpected behaviour on my system. If I have
compilation fails with 'cannot resolve symbol' error for HashSet constructor. It even said - TestHashSet.java:27: incompatible types found : HashSet required: java.util.Set Set s = new HashSet(); ^ TestHashSet.java:28: cannot resolve symbol symbol : constructor HashSet (java.util.Set) location: class HashSet Set hash = new HashSet(s);
Compilation succeeds only if I do individual imports for Set and HashSet ( I tried for ArrayList, List, Collection too ).