Improve Java performance with MAP.
Add Contains keys Next Data StructureHashMap O(1) O(1) O(h/n) Hash TableEnumMap O(1) O(1) O(1) ArrayLinkedHashMap O(1) O(1) O(1) Hash Table+Linked ListTreeMap O(log n) O(log n) O(log n) Red-black treeConcurrentSkipListMap O(log n) O(log n) O(1) Skip ListConcurrentHashMap O(1) O(1) O(h/n) Hash tableIdentityHashMap O(1) O(1) O(h/n) ArrayWeakHashMap O(1) O(1) O(h/n) Hash table