Hi

In the JAX-RS users thread which I referred to below I did ask about and I don't think I got a +1 from one the spec leads on having ParamConverterProvider supporting List, please check the archives. And as I said IMHO the converters should not deal with interpreting for ex the whole query component value.
But can you investigate please how Jersey handles it ?

In Pre-match you can figure out if a given CSV value is a multi-value or not based on the current request URI (the relative parts), I agree it will be less safe compared to the use of annotations

Cheers, Sergey

On 17/10/16 15:56, Diego Ruotolo wrote:
Hi Sergey,

I think you are definitively right when you say you don't want to introduce
a CXF specific extension at a standard JAX-RS interface level. But taking a
look at the JAX-RS specs it is not specified that ParamConverter should
handle just single values in a collection and not the whole collection: I
think that both interpretations are valid, but maybe I am missinig
something.

Regarding the use of a @PreMatch filter, I don't think it is possible: I
can't read annotations on a method parameter in a @PreMatch filter since
the server resource is not bound yet, and I can't change parameter values
in a post-match filter since it is impossible to change the URI (by specs).
Furthermore, in a post-match filter the server resource is bound but not
yet "filled" with values.

Thanks,

Diego

diego.ruot...@gmail.com

2016-10-17 16:28 GMT+02:00 Sergey Beryozkin <sberyoz...@gmail.com>:

Hi Diego

But that would introduce a CXF specific extension at a standard JAX-RS
interface level. In general I'm quite open to adding new extensions but
I'd rather not to in this case...Besides, IMHO, it really should be the
job for the JAX-RS runtime, to parse the multivalued query/matrix
properties.
What you might want to experiment with is to add a prematch request filter
which will reset a query string if needed to have List<String> working for
either a=1&a=2 or a=1,2, etc



Thanks, Sergey

On 17/10/16 12:46, Diego Ruotolo wrote:

Hi Sergey,

thanks for your answer.
I think a good solution could be to pass the ParamConverter a string
containing all the values of a multi-valued query parameter, and let the
user build the collection object.
So, if I have a query string like:
MY_PARAM=VALUE_1&FOO=BAR&MY_PARAM=VALUE_2, the ParamConvert should
receive
the string MY_PARAM=VALUE_1&MY_PARAM=VALUE_2, and the user should build
the
collection in in the fromString() method. In this way the user can deal
with both the whole collection and its single values.
I also suggest this behaviour should be activated through a property in
order not to break backward compatibility.
What do you think?

Thanks,

Diego

2016-10-17 11:47 GMT+02:00 Sergey Beryozkin <sberyoz...@gmail.com>:

Hi

Thanks for this query, let me redirect to the CXF users list.

FYI, CXF JAX-RS runtime prepares a List itself and only expects
ParamConverters if any to convert individual values.

I believe RI (Jersey) will also act the same way - but I may be wrong
now.
You can check a "ParamConverter and Collections" thread on the jaxrs
users
list. My understanding there was no any agreement reached.

Cheers, Sergey


On 16/10/16 23:48, Diego Ruotolo wrote:

Hi everybody,

this is my first post to this mailing list.
I am using Apache CXF and I have the following problem: I need to read a
multiple-value query parameter that is written in a
comma-separated-values (CSV) format, hence non standard HTTP way.
I know that this will be fixed in versions 3.1.8 and 3.2.0 with the
contextual property "parse.query.value.as.collection", as written here:
https://issues.apache.org/jira/browse/CXF-6941
but the above solution works for ALL query parameters, I want to be
selective, for instance I just want query parameters annotated with
@MyAnnotation to be parsed as CSV collection, other query parameters may
accept commas as a value.
Therefore I've written a ParamConverter provided by a
ParamConverterProvider: the latter reads the annotation and returns the
appriopriate ParamConverter that converts a String into a List. But this
is not working since the returned List is used as first element of the
linked method parameter, so in the end I have a List of List.

Example:

Query parameter: MY_PARAM=VALUE_1,VALUE_2,VALUE_3
Method parameter: List<?> myParam; // Here I put "?" instead of "String"
as generic type in order to explain this example
ParamConverter fromString() method: return
Arrays.asList(value.split(",")); //returns a List<String>
Expected result: myParam is a List<String>, a list of 3 elements
(VALUE_1, VALUE_2, VALUE_3)
Actual result: myParam is a List<List<String>>, a list with one element,
this single element is a list of 3 elements (VALUE_1, VALUE_2, VALUE_3)

It seems that when used in conjuction with a List (a Collection?) method
parameter, a ParamConverter works per-element, not for the whole list.
Is this the correct behaviour? Do you know some work-around that I could
use without writing an Apache CXF Interceptor (I don't want to be bound
to an implementation of JAX-RS) ?
I've noticed that Jersey has a similar issue too:
https://java.net/jira/browse/JERSEY-2763

Thanks in advice,

best regards



--
Sergey Beryozkin

Talend Community Coders
http://coders.talend.com/






--
Sergey Beryozkin

Talend Community Coders
http://coders.talend.com/

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