Re: InetAddress.equals() Anomoly?

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From: Pete Loveall (psl_at_ametx.com.NO_SPAM)
Date: 01/09/05

  • Next message: Bruno Jouhier [MVP]: "Re: InetAddress.equals() Anomoly?" 
    Date: Sun, 9 Jan 2005 08:02:31 -0600

    "Bruno Jouhier [MVP]" <bjouhier@club-internet.fr> wrote in message
    news:O1zEqCj9EHA.1188@tk2msftngp13.phx.gbl...
    >
    > If the specs says that then:
    >
    > 1) The J# implementation is buggy because it does not follow the specs.
    >
    > 2) The specs are bad because they violate the normal semantics of
    > "equals".
    >
    > But I agree with you, point 1) should prevail then and the J# guys should
    > fix the implementation so that it conforms to the specs (even if the specs
    > are wrong).

    The specs are not "wrong", they are simply in conflict with what your think
    they should be. The Java spec for object equality was written in the very
    earliest of development of the Java language to be able to handle specific
    issues such as this.

    The original specification for InetAddress says nothing about the format of
    the toString() method. For that matter, different JVM's have implemented
    toString() in a variety of ways. J# is the only "JVM", by the way, which
    converts DNS names to conical DNS names if the DNS server returns that, and
    does reverse DNS lookups on every connection. InetAddress is exactly what
    its name implies: a holder for an Internet address, otherwise known as an IP
    address. All of the members relate to the IP address, not the DNS (or
    reverse DNS) name. Even getHostName() will return the local computer's
    "name" if the InetAddress does not have a DNS name stored in it. This focus
    on IP address has made it possible for Sun to derive IPv4 and IPv6 classes
    which can be used interchangeably in existing or new programs written with
    no IPv4 vs. IPv6 awareness. Quite forward thinking, if you ask me.

    The Java language accounted for variances in class use, such as this, and in
    the process made a very flexible programming language. If the creator of a
    class says "this is what this class is for", then the creator can make all
    relevant overrides to reflect that. Should the class have some ancillary
    capabilities which do not affect the primary purpose of the class, then
    those ancillary capabilities can safely be ignored when considering object
    equality. It is a different viewpoint from yours, but it is the viewpoint
    that is written into the Java specification and should be readily understood
    and accepted by anyone writing Java or J# applications.

    Peter Loveall

  • Next message: Bruno Jouhier [MVP]: "Re: InetAddress.equals() Anomoly?"

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