Why HashMap is transient inside HashSet implementation?

[Shishir R Verma]

Hi,

This question might have been asked earlier and probably a dumb question to ask, but It is somehow stuck in my mind.
I was looking at the code of HashSet, which actually looks like a wrapper around HashMap. I noticed that the HashSet class is implementing Serializable and HashMap is declared as transient variable inside it. Why HashMap is transient?

Thanks in advance...

[Winston Gutkowski]

Shishir Rmv wrote:I was looking at the code of HashSet, which actually looks like a wrapper around HashMap. I noticed that the HashSet class is implementing Serializable and HashMap is declared as transient variable inside it. Why HashMap is transient?

Almost certainly because a HashSet can be translated into a more compact serialized form than an equivalent HashMap; but at the end of the day, without talking to the designer, it's pure speculation.

Perhaps a bit more source-code gazing is in order.

Winston

[Shishir R Verma]

Winston Gutkowski wrote:
Almost certainly because a HashSet can be translated into a more compact serialized form than an equivalent HashMap; but at the end of the day, without talking to the designer, it's pure speculation.

Winston

Thanks Winston. That's what I was thinking. And in the end of the day while deserialzing it back, it loses its compactness anyways.