title: concurrent HashMap: checking size
body: <p>Concurrent Hashmap could solve synchronization issue which is seen in hashmap. So adding and removing would be fast if we are using synchronize key work with hashmap. What about checking hashmap size, if mulitple threads checking concurrentHashMap size? do we still need synchronzation key word: something as follows:</p>
  
  <pre><code>public static synchronized getSize(){
       return aConcurrentHashmap.size();
  }  
  </code></pre>