hi Sergey,
Which JAXB version are you using? Here is 2.3.8, but there is no
"setIgnoreEmptyArrayValues(...)" method in JSONProvider, and there is no way
either to change the convention within createWriter(...) inherited method
because of the super class private fields/methods.
I could however manage to change the flag through reflection... but still no
luck.
Our JAXB generated class looks like:
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {
"dataproviders"
})
@XmlRootElement(name = "dataproviders")
@SuppressWarnings("all") public class Dataproviders {
@XmlElement(name = "dataprovider", nillable = true)
protected List<Dataprovider> dataproviders;
public List<Dataprovider> getDataproviders() {
if (dataproviders == null) {
dataproviders = new ArrayList<Dataprovider>();
}
return this.dataproviders;
}
}
If the list contains several elements, we get (as expected):
{"dataproviders":{"dataprovider":[{...},{...},...]}}
If the list contains one element, we now get (as expected):
{"dataproviders":{"dataprovider":[{...}]}}
But... if the list is empty, we still get (and this is not what we were hoping
for):
{"dataproviders":""}
I'll investigate more ;-)
Cheers,
eric
-----Original Message-----
From: Sergey Beryozkin [mailto:[email protected]]
Sent: lundi 2 février 2015 15:01
To: MULLER, Anthony; FESTINGER, Eric
Cc: [email protected]
Subject: Re: CXF 2.3.8 + Jackson or Jettison 1.3.7 ?
Actually,
JSONProvider.setIgnoreEmptyArrayValues(true);
will work right now, I see a test confirming it,
JSONProviderTest.testManyTagsEmptyArray in the CXF source
Cheers, Sergey
On 02/02/15 13:48, Sergey Beryozkin wrote:
> Hi Anthony, Eric,
>
> CC-ing to the users as it can be of interest,
>
> On 02/02/15 13:17, MULLER, Anthony wrote:
>> Hello again,
>>
>> About this issue:
>>
>>>> 2) when there is only one element, we get reports: {report: {name =
>>>> "foo"}}
>>>> --> they'd like: reports: {[report: {name = "foo"}]}
>>
>> Eric has implemented a solution which consists in scanning our whole
>> JAXB POJO folder (generated from XSD) and then fill in the
>> serializedAsArray() structure. It seems to work fine, we need to check
>> it more in details to be sure there is no regression.
>
>
> If you can write a code like that then you can write a new Jettison in a
> couple of days :-). Nice work Eric
>
>>
>> About this second issue, we are a bit stuck:
>>
>>>> 1) when no element in an array, we get: reports: ""
>>>> --> they'd like: reports : [] or reports : null
>>
>> So, when there is no element, we didn't know how we can configure
>> Jettison to write something different than "" (empty quote). In most
>> of cases, this behavior is fine (for instance <name></name> becomes
>> {name : ""}).
>>
>> However, in some cases, basically when an element can only contain a
>> list of elements (reports --> report), we're trying to produce
>> something different:
>>
>> Currently : {reports : ""}
>> Target output : {reports : null}
>>
>> Do you see any options we have to do that? We explored some additional
>> settings introduced into Jettison but we cannot deal with this issue
>> right now...
>>
>
> So you have a 'reports' property as an array key and Jettison reports ""
> when a JAXB bean 'reports' property is empty ? Looks like it is a
> Jettison bug and needs to be fixed - I'll investigate for Jettison 1.3.7
> (in a few weeks realistically).
>
> I think the correct JSON output is actually
> "{"reports":[]}"
>
> but if "{reports : null}" is also acceptable then
>
> might be worth experimenting with some of JAXB properties, I guess the
> following link can help:
>
> http://blog.bdoughan.com/2012/12/jaxb-representing-null-and-empty.html
>
> You'd probably 'wrap' a given list with XMLElementWrapper and set its
> nillable attribute to true, something like that...
>
> In meantime I'll look into making sure Jettison can produce
> "{"reports":[]}"
>
> Thanks, Sergey
>
>> Thanks again for your help Sergey,
>>
>> Anthony
>>
>>
>> -----Original Message-----
>> From: MULLER, Anthony
>> Sent: lundi 2 février 2015 11:09
>> To: 'Sergey Beryozkin'; FESTINGER, Eric
>> Subject: RE: CXF 2.3.8 + Jackson or Jettison 1.3.7 ?
>>
>> Thanks for your feedback and various proposal Sergey!
>>
>> Anthony
>>
>> -----Original Message-----
>> From: Sergey Beryozkin [mailto:[email protected]]
>> Sent: lundi 2 février 2015 11:05
>> To: FESTINGER, Eric; MULLER, Anthony
>> Subject: Re: CXF 2.3.8 + Jackson or Jettison 1.3.7 ?
>>
>> Hi Eric
>>
>> Indeed, providing custom XMLStreamWriter or Reader is the most flexible
>> option to manage various Jettison specific issue. It is a rather complex
>> approach but it can offer a way to control the process...
>> Cheers, Sergey
>> On 02/02/15 07:36, FESTINGER, Eric wrote:
>>> hello Sergey and Anthony,
>>>
>>> ... and thanks for the explanation about this current patch.
>>>
>>> In a meanwhile, I have made some parser which reads our JAXB
>>> generated classes, and populate the
>>> xmlStreamWriter.serializeAsArray(...).
>>>
>>> Best regards,
>>>
>>> eric
>>>
>>> -----Original Message-----
>>> From: Sergey Beryozkin [mailto:[email protected]]
>>> Sent: dimanche 1 février 2015 22:07
>>> To: MULLER, Anthony
>>> Cc: FESTINGER, Eric; [email protected]
>>> Subject: Re: CXF 2.3.8 + Jackson or Jettison 1.3.7 ?
>>>
>>> Hi Anthony
>>>
>>> I'm CC-ing to the users list because it can be of interest to others.
>>>
>>>
>>> On 30/01/15 09:35, MULLER, Anthony wrote:
>>>> Hello Sergey,
>>>>
>>>> About this issue:
>>>> http://jira.codehaus.org/browse/JETTISON-142
>>>>
>>>> Do you think this will help to troubleshoot the array serialization
>>>> issue with Jettison?
>>> Not really. JETTISON-142 patch provides a fairly specific work-around
>>> which works only in JSON->XML->JSON auto conversion cases. The challenge
>>> there is to investigate if JSON-> XML or JAXB Bean -> JSON can also
>>> work. Most likely it is not related to the issues you are seeing
>>>>
>>>> In our case, customers provide us several times the same feedback
>>>> about the difficulty to handle the JSON output:
>>>>
>>>> 1) when no element in an array, we get: reports: ""
>>>> --> they'd like: reports : [] or reports : null
>>>> 2) when there is only one element, we get reports: {report: {name =
>>>> "foo"}}
>>>> --> they'd like: reports: {[report: {name = "foo"}]}
>>>>
>>>> We already know about some existing settings in Jettison
>>>> (serializedAsArray flag and this other parameter to provide tag
>>>> names to deal with), but it is not flexible enough for us because we
>>>> have some cases when a tag is effectively in an array, and another
>>>> XML document where the same tag name is not in an array...
>>> Jettison 1.3.6 introduces namespace-'local' array keys. For example,
>>> 'n1.a', 'n2.b', where 'n1' and 'n2' are namespace prefixes registered in
>>> a separate namespace map.
>>> So, if you have a single JSONProvider handling multiple documents where
>>> an element with a name 'a' is a list in not all of the documents then
>>> most likely you can use something like 'n1.a', etc, to uniquely identify
>>> such a property.
>>>
>>> I hope migrating to Jettison 1.3.6 can help. Let me know please
>>> Indeed, Jackson would offer a more robust alternative but you'd need to
>>> annotate the given beans with Jackson annotations...
>>>
>>> HTH, Sergey
>>>
>>>>
>>>> I'm looking forward to get your point of view.
>>>>
>>>> Best regards,
>>>> Anthony
>>>>
>>
>
>
--
Sergey Beryozkin
Talend Community Coders
http://coders.talend.com/
Blog: http://sberyozkin.blogspot.com
