title: Volatile HashMap vs ConcurrentHashMap
body: <p>I have a cache class which contains a <code>volatile HashMap&lt;T&gt;</code> to store cache items.</p>
  
  <p>I'm curious what would be the consequences of changing <code>volatile HashMap</code> to <code>ConcurrentHashMap</code>?</p>
  
  <p>Would i gain performance increase? This cache is readonly cache.</p>
  
  <p>What would be the best option to use? just HashMap? Cache is being populated on a interval.</p>