import com.googlecode.concurrentlinkedhashmap.ConcurrentLinkedHashMap; public class Example { public static void main(String[] args) { ConcurrentLinkedHashMap<String, Integer> map = new ConcurrentLinkedHashMap.Builder<String, Integer>() .maximumWeightedCapacity(100) .build(); map.put("key1", 1); map.put("key2", 2); Integer value = map.get("key1"); map.remove("key2"); boolean containsKey = map.containsKey("key2"); int size = map.size(); map.clear(); } }