ConcurrentHashMap

Java中的同步集合与并发集合有什么区别？
https://blog.csdn.net/u014308482/article/details/53117980

concurrentHashMap
segment extends ReentrantLock

Java中ConcurrentHashMap的并发度是什么？

concurrencyLevel  表示传入的并发程度
ssize表示实际的并发程度。
while (ssize < concurrencyLevel) {
            ++sshift;
            ssize <<= 1;
        }

hashMap
http://www.importnew.com/7099.html
ConcurrentHashMap
http://www.importnew.com/22007.html