title: AWS Lambda RequestHandler for a void output
body: <p>Consider a simple Lambda written in Java:</p>
  <pre><code>import com.amazonaws.services.lambda.runtime.Context; 
  import com.amazonaws.services.lambda.runtime.RequestHandler;
  
  public class Hello implements RequestHandler&lt;Integer, String&gt;{
      public String handleRequest(int myCount, Context context) {
          return String.valueOf(myCount);
      }
  }
  </code></pre>
  <p>The handler interface is defined as <code>RequestHandler&lt;InputType, OutputType&gt;</code>, but when my Lambda reacts to events and just does some side effects, is the output type unnecessary and I have to write something like this:</p>
  <pre><code>public class Hello implements RequestHandler&lt;SNSEvent, Void&gt;{
      public Void handleRequest(SNSEvent snsEvent, Context context) {
          ...
          return null;
      }
  }
  </code></pre>
  <p>Which is annoying.</p>
  <p>Is there an alternative to <code>RequestHandler</code> for a <code>void</code> handler?:</p>
  <pre><code>public class Hello implements EventHandler&lt;SNSEvent&gt;{
      public void handleEvent(SNSEvent snsEvent, Context context) {
          ...
      }
  }
  </code></pre>