Java Collections.sort - помогает мне удалить предупреждение непроверенное

Поскольку BeanComparator не является универсальным, вам просто нужно подавить.

ОБНОВЛЕНИЕ: На самом деле, если это вас достаточно беспокоит, вы можете разветвить базу кода на сделайте его универсальным, поскольку это открытый исходный код.

Yes, you are supposed to use @SuppressWarnings("unchecked"). There is no reason to think the comparator not using generics can cause a problem in that case.

You could always switch to using Google Collections.

They support Generics.

The only way to remove the warning would be to change the code of BeanComparator, but even if you could, unless you made it a specific wrapper that understands your particular type, the concept wouldn't work well. The class operates on any object by reflection which may or may not have the method. It is inherently not typesafe.

The simplest way around the warning is to implement your own comparator:

 public class QuestionComparator extends Comparator<Question> {
      private BeanComparator peer = new BeanComparator("questionId");

      public int compare(Question o1, Question o2) {
             return peer.compare(o1, o2);
      }
 }

You could also implement equals if it matters, and call the BeanComparator equals method like this:

   public boolean equals(Object o) {
       //boiler plate code here to ensure o is an instance of Question and not null
       return ((QuestionComparator) o).peer.equals(peer);
   }