RE: SAX2 RFD: Inheritance vs. Modification vs. Amalgamation
A quick follow up to my last post ... I did a sanity check on the mechanism I descibed earlier and it looks as though there's a problem. It works perfectly as described for Sun JDK1.2.1 (with the exception that the error to catch is AbstractMethodError rather than NoSuchMethodError). Sadly it fails for Sun JDK 1.1.8 (the only other I've got handy at the mo'). The problem is that the older JDK won't allow the instantiation of a class which implements an older version an interface when a newer version of that interface is present on the classpath: new throws an IncompatibleClassChangeError (as a result of a failure during classloading I presume). By comparison JDK1.2.1 allows the instantiation, and throws AbstractMethodErrors if methods from the newer interface are called on the old class. The upshot is that with JDK1.1.8 you wouldn't be able to create an instance of a SAX1 parser in the presence of the SAX2 interfaces, which means that my adapter approach can't get off the ground. As far as I can see JDK1.2.1 is following the JLS here, and JDK1.1.8 (and possibly earlier) is in error. The fact that it's JDK1.1.Xs fault doesn't help all that much tho'. I'll report it as a bug and see what feedback I get from Sun. If anyone's want's a peek at the code for the test cases to make sure I'm not missing something obvious, please let me know. Assuming this is a genuine problem I have to pick one of Davids options. I'd have to go along with Tim and back option (2). Cheers, Miles -- Miles Sabin Cromwell Media Internet Systems Architect 5/6 Glenthorne Mews +44 (0)181 410 2230 London, W6 0LJ msabin@c... England xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1 To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
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