title: Java equivalent of .NET Action<T> and Func<T,U>, etc
body: <p>Are there any standard generic "callback" or "function/method" types in Java, like <code>System.Action&lt;T&gt;</code> or <code>System.Func&lt;T,U&gt;</code> in .NET?</p>
  
  <p>In my concrete case, I need a class that wraps a method that takes one (generic) parameter of type <code>T</code> and returns nothing (i.e. <code>void</code>).</p>
  
  <p>Yes, it's easy enough to create such a class/interface for myself, but I'd prefer a standard library class if there is one.</p>