#探索 ConcurrentHashMap 高并发性的实现机制 http://www.ibm.com/developerworks/cn/java/java-lo-concurrenthashmap/index.html?ca=drs-
#Java 理论与实践: 并发集合类 http://www.ibm.com/developerworks/cn/java/j-jtp07233/
#Java 理论与实践: 构建一个更好的 HashMap http://www.ibm.com/developerworks/cn/java/j-jtp08223/