title: Completion handlers in Java?
body: <p>I've been coding for iOS and I'm quite familiar with the concept of blocks in Objective-C.
  Now I'm leaning Java for Android and trying to convert some apps from Android to iOS.</p>
  
  <p>I read that there no perfect equivalent of blocks in Java, so I'd like to know what is the best alternative to implement completion handlers or anything that could work similarly.</p>