I flagged this answer as "Not an answer," since it doesn't address the question — "Is this just an unfortunate shortcoming of Java's autoboxing/unboxing specification, or is there a good reason for this?" — but simply offers a different way to do what the asker was trying to do when they discovered the topic of the question.
The flag was declined. Based on this comment, I flagged again, using the "other" flag so I could enter a brief explanation of why it didn't answer the question. The second flag, too, was declined.
Am I missing something? Does this answer somehow actually answer the question?