title: Is is acceptable to declare a private class as an alias?
body: <p>In <a href="https://stackoverflow.com/questions/2413606/using-directive-in-java/2413618#2413618">my answer from yesterday</a> I called the following piece of code "a hack":</p>
  
  <pre><code>final class MyMap extends HashMap&lt;SomeSuperLongIdentifier, OtherSuperLongIdentifier&gt; {}
  // declared MyMap as an alias for readability purposes only
  
  MyMap a = new MyMap();
  a.put("key", "val");
  </code></pre>
  
  <p>Giving it another thought, this does not seem like a bad idea at all, but I might be missing something. Are there any potholes I missed out on? Is this an acceptable (possibly creative) way for declaring aliases in Java?</p>