Hi John, thanks for your answer. Your proposal was my initial thought, but the problem is that ParamConverter in Apache CXF works considering every single element in a List, not the List as a whole, meaning that rawType in ApacheCXF will never be a List but, in the case of List<String>, a String. In other words when I have a resource method with a List<MyObject> as argument, ApacheCXF allows you to deal with the single MyObject that compose the List, not with the whole List.
Hope this clarify. Thanks, Diego 2016-10-24 2:20 GMT+02:00 John D. Ament <john.d.am...@gmail.com>: > Hi, > > So just a thought. Why can't this be accomplished today with a > ParamConverter and a custom annotation? > > Looking at the samples repo - > https://github.com/javaee-samples/javaee7-samples/blob/ > master/jaxrs/paramconverter/src/main/java/org/javaee7/ > jaxrs/paramconverter/MyConverterProvider.java#L18 > - > it seems like rawType can be List.class, generic type can be String.class, > and annotation[] containing whatever annotation you want to demarcate that > it should be your customer CSV format. > > John > > On Sun, Oct 23, 2016 at 6:44 PM Diego Ruotolo <diego.ruot...@gmail.com> > wrote: > > > I have to say that I don't understand your objection (in my defense: here > > is almost 1:00 AM... :-) ), could you please clarify? > > > > Probably the best solution will be to have a kinda > > MultipleParamConverter<T> interface in JAX-RS 2.1 specs defining two > > methods: > > T fromStrings(String[] values); > > String[] toStrings(T value); > > > > The fromStrings() method will build the object used as argument in the > > requested resource method. > > But I'll let people more expert than me discuss on this. > > > > Thanks, > > > > Diego > > > > 2016-10-24 0:30 GMT+02:00 Sergey Beryozkin <sberyoz...@gmail.com>: > > > > > I can't agree to this. So a user registering a custom List provider > > breaks > > > the runtime ensuring the service code sees all the multiple values. > > > > > > I can try and work with spec leads on clarifying it for JAX-RS 2.1. > > > > > > Thanks, Sergey > > > > > > > > > On 23/10/16 23:27, Diego Ruotolo wrote: > > > > > >> Hi, > > >> > > >> - when using multiple-value parameters passed in the URI in an HTTP > > >> > > >>> compliant-way (PARAM=V1&PARAM=V2&PARAM=V3), the ParamConverter takes > > only > > >>>> the first value, hence if the ParamConverter builds a list, it will > > be a > > >>>> list of only one value > > >>>> > > >>>> > > >>> Are you saying this loses V2 & V3 ? > > >>> > > >>> > > >> Yes, in this case it loses V2 & V3. AFAIK the only way in Jersey to > get > > a > > >> correct parsing of a multiple-valued query parameter is not to write a > > >> custom ParamConverter. > > >> > > >> Cheers, > > >> > > >> Diego > > >> > > >> > > >> > > >> Thanks, Sergey > > >>> > > >>> > > >>> - when not using a custom ParamConverter, the multiple-value > parameter > > >>> > > >>>> parsing (the example above) works correctly > > >>>> > > >>>> Therefore what I am trying to achieve (CSV query parameter) can be > > done > > >>>> on > > >>>> Jersey by developing a custom ParamConverter, without explicitly > write > > >>>> an > > >>>> Jersey extension, because it is a single value that generates a List > > >>>> that > > >>>> will be passed as a whole as argument of the requested resource > > method. > > >>>> > > >>>> Hope that this clarify, > > >>>> > > >>>> cheers, > > >>>> > > >>>> Diego > > >>>> > > >>>> 2016-10-17 17:37 GMT+02:00 Sergey Beryozkin <sberyoz...@gmail.com>: > > >>>> > > >>>> 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/ > > >>>>> > > >>>>> > > >>>>> > > >>>> > > >>> -- > > >>> Sergey Beryozkin > > >>> > > >>> Talend Community Coders > > >>> http://coders.talend.com/ > > >>> > > >>> > > >> > > > > > >
