Sashlik

public class HandlerFactory {
  
   public DataHandler getInstance(String type) {
      if (type.equals("string"))
         return new StringDataHandler();
      else if (type.equals("byte"))
         return new ByteDataHandler();
      else if (type.equals("long"))
         return new LongDataHandler();
      else
         throw new IllegalArgumentException("Unknown type");
   } 
}