Java ConcurrentHashSet

Java gives you ConcurrentHashMap but no ConcurrentHashSet — which is mildly infuriating when you need a thread-safe set. Before Java 8, the workaround was wrapping a ConcurrentHashMap. Java 8 fixed this properly. Here are both approaches.

• Java 8

ConcurrentHashMap.newKeySet()

• Java 8

Map<String, Boolean> map=new ConcurrentHashMap();
Collections.newSetFromMap(map)

ConcurrentHashSet