Hi Reto,
I think you have found a very edgy case :-) The reason being is
header value equality for many HTTP headers is not equal to the
string equality. Thus it is unlikely that such map equality will do
what is really required.
Bill, i think the issue is when a type compatible map, such as
HashMap<String, List<String>> is compared with the map returned by
the getRequestHeaders. Equality of two maps returned by
getRequestHeaders could be supported.
It is possible to support case-insensitive look up, i.e. not
mandating that a developer convert to upper or lower case, and
equality to other type equivalent maps if we mandate, as you point
out, that keys are always lower cased. Thus a developer using another
type equivalent map is required to put keys in lower case.
Given that we are just a couple of days away from making the final
cut to the API it is important to minimize the changes (if any) we
make to resolve this edge case.
Paul.
On Sep 1, 2008, at 12:11 PM, Reto Bachmann-Gmür wrote:
> HttpHeaders.getRequestHeaders has to return a
> MultivaluedMap<java.lang.String,java.lang.String> that is case-
> insensitive with regards to keys. I'm not sure how such a case
> insensitive map is supposed to work exactly (e.g. what does keySet
> return?) and I think that it might be quite hard to have a
> definition compatible the the API for the java.util.Map (which is
> extended by MultivaluedMap).
>
> An issue is map identity. The javadoc for java.util.Map.equals
> says: "Returns true if the given object is also a map and the two
> maps represent the same mappings." as the mapping of keys with
> different casing is the same I would think that two maps are equals
> is they differ only by the casing of the keys, however the text
> more specifically says: "More formally, two maps m1 and m2
> represent the same mappings if m1.entrySet().equals(m2.entrySet
> ())." The latter condition is only met if the EntryS contains the
> key with the same casing (or if the keyset is expanded to contain
> possible casings of a key), but this is not defined by the jax-rs
> spec.
>
> I think jax-rs should not introduce a case-insensitive map but
> rather either specify that all-lower (or upper) case strings are to
> be used as keys or introduce a class like "CaseInsensitiveString"
> used as key in the map.
>
> Reto
>