On Mon, Dec 18, 2017 at 12:01 PM, Simon Joseph Aquilina <[email protected]> wrote: > I have used the ObjectMapper on its own and you confirm that it works as you > say. > It looks like my issue is with the combination with Cxf then.
Ah. Yes, it may well be that Cxf for some reason chooses different defaults. I am not sure why (I think this setting is somewhat confusing), but traditionally one reason has been that some XML frameworks have had this behavior due to difficulties in distinguishing case of single-element array and simple object value. -+ Tatu +- > > > On Monday, December 18, 2017 at 8:33:33 AM UTC+1, Tatu Saloranta wrote: >> >> On Sun, Dec 17, 2017 at 4:01 PM, Simon Joseph Aquilina >> <[email protected]> wrote: >> > Hello, I am using com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider >> > to >> > generate a JSON output of my objects. However when a List has only one >> > element the JSON output I get is that of a single object and not a list >> > of >> > objects. >> > >> > For example if I have a List<User> users = new ArrayList() with only one >> > User object in this I get the following output: >> > >> > "users" : { "username" : "hello" } >> > >> > and not >> > >> > "users" : [{"username" : "hello" } >> > >> > I have been looking on the internet for a solution but could not find >> > any >> > (using fasterxml jackson library was listed as a solution initself which >> > is >> > why I am using it now). I initialise my JacksonJsonProvider as follows: >> > >> > >> > ObjectMapper mapper = new ObjectMapper(); >> > return new JacksonJsonProvider(mapper); >> > >> > And the list is annotated as follows: >> > >> > @XmlElement(name="users") >> > List<User> users = new ArrayList<>(); >> > >> > What can I do to force JacksonJsonProvider to output a java.util.List >> > always >> > as a list in JSON even when such list has only one element? >> >> By default, Jackson serializes Lists as Lists. It does not unwrap >> single element. >> >> It is possible to change this behavior by enabling >> >> SerializationFeature.WRITE_SINGLE_ELEM_ARRAYS_UNWRAPPED >> >> (or using `@JsonFormat` per-property annotation with similar setting) >> >> so I would try to figure out who is configuring behavior either via >> ObjectMapper, >> or by declaring `users` property with formatting options. >> >> I hope this helps, >> >> -+ Tatu +- > > -- > You received this message because you are subscribed to the Google Groups > "jackson-user" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "jackson-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. For more options, visit https://groups.google.com/d/optout.
