ConcurrentHashMap vs Synchronized HashMap

Question

What is the difference between using the wrapper class, SynchronizedMap, on a HashMap and ConcurrentHashMap?

Is it just bein

Answer 1

A simple performance test for ConcurrentHashMap vs Synchronized HashMap . The test flow is calling put in one thread and calling get in three threads on Map concurrently. As @trshiv said, ConcurrentHashMap has higher throughput and speed for whose reading operation without lock. The result is when operation times is over 10^7, ConcurrentHashMap is 2x faster than Synchronized HashMap.