Re: Java/OO techniques for modularity and re-use

=?ISO-8859-1?Q?Arne_Vajh=F8j?= <>
Sun, 01 Jul 2007 15:54:18 -0400
Richard Maher wrote:

Since SSLSocket inherits from Socket then you can make your
t3sock of type Socket (you can assign from a subtype to a
super type).

But because SSLSocket "extends" Socket, surely I have to instantiate a
SSLSocket object somewhere don't I?

Really no need for this: -
  sockFactory = (SSLSocketFactory)SSLSocketFactory.getDefault();
  t3Sock = (SSLSocket)sockFactory.createSocket();

That works fine if t3Sock is declared to have type Socket.

And since all methods are virtual in Java, then if t2Sock is
a SSLSocket, then that class's methods will be used.

What about all the Value-Added SSL bits that the SSLSocket class must
bolt-on to a Socket?

If you need to use a SSL specific funtion you can use:

You're casting t3Sock (a Socket object) as a SSLSocket object there right? I
haven't missed some abstract-class or Interface wizardry? So I've got a
vanilla Socket and cast it as a SSLSocket to call, say startHandshake(), and
it's not gonna complain about a bodgy brick-veneer job, absent any
certificate or crypto-algorithm info?

t3Sock is declared as a Socket, but it it actually is a SSLSocket, then
it can be cast to a SSLSocket and therefore use the SSLSocket
specific methods.

I'd find it easier to picture it the other way around where we have a
SSLSocket and our casting it as a Socket effectively masks out all the SSL
bits, but who cares?

You can not assign a Socket to a SSLSocket, so it has to be this way

But that is not "nice".

It's certainly more appealing than the attached code (look for "sslReqd")



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