Ah, yes! Sweet! So *that's* how you submit a generic type to this
infrastructure!! I had stumbled across something very similar, although a
bit more long winded, as the last thing I tried last night, but I just
happened across it based on a comment of the guy I'm working with on this
and I tried it and it actually then gave me my wrapper envelope back with
my domain class(es) inside it. Here's the syntax I tried last night which
worked (& I'm going to try your more compact form immediately):
GenericType<ResponseEnvelope<FooBar>> fooResponseEnvType = new
GenericType<ResponseEnvelope<FooBar>>() {};
// then pass fooResponseEnvType to the get(...) method like so:
ResponseEnvelope<FooBar> envelope4ReuseMkt = client.target("
http://localhost:8080/v1.1/rs")
.path("foobar")
.path(fooBarId.toString())
.request(MediaType.APPLICATION_JSON_TYPE)
.get(fooResponseEnvType);
Thanks so much for your comment, however, as your code is much more compact
which I like. Where, pray tell, is this stuff documented? Almost
*everyone* is using domain objects (or DTOs, etc.) with these services, so
the examples with simple String data types aren't representative of the
techniques needed to work with domain objects, generic types and other
things commonly found in enterprise environments (like the GenericType
utility class you pointed out). We have a pretty crazy domain model, so I
am going to need to get much more deeply into things like this, where is
this GenericType utility discussed, beyond a javadoc?
I would also *really* love to understand what such facilities exist, how
they're intended to be used, what kids of functionality is currently
support and even, if you guys know, what direction things are headed in.
I've been over (I think) most of the
https://jersey.java.net/documentation/latest... site but I haven't found
discussion of things like GenericType, sorry if I'm being dense but can you
point that out? (Thanks again.)
While I have your ear, can you answer two relatively simple questions? My
services are working when I don't explicitly register any JSON Features at
all, but I do have these mvn dependencies in my pom.xml:
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>${jackson.version}</version>
</dependency>
What JSON databinding am I using? If I explicitly enable the
JacsonFeature, I get very different behavior (stackoverflow errors).
The second dumb question is, is the @JsonIgnore annotation in domain
classes still how you are supposed to prevent recursive stackoverflow JSON
serialization errors? I ask because if I explicitly enable the
JacksonFeature as I described in my post, I would assume that I am
definitely using Jackson but the @JsonIgnore annotations within my domain
classes appear to be ignored themselves and I suffer stackoverflow
errors. We have a very complex domain model so I want to stay on top of
the best techniques for managing domain classes that have a lot of
relationships among them.
Thanks Jakub, appreciate your help *immensely*!
-=j=-
On Wed, Jan 8, 2014 at 5:30 AM, Jakub Podlesak <jakub.podlesak_at_oracle.com>wrote:
> Hi Jack,
>
> Please try to use the following type when reading the entity:
>
> ResponseEnvelope<FooBar> envelope = svcResponse.readEntity(new
> javax.ws.rs.core.GenericType<ResponseEnvelope<FooBar>>(){});
>
> Does it help?
>
> ~Jakub
>
>
> On 07 Jan 2014, at 22:05, Jack Lista <jackalista_at_gmail.com> wrote:
>
> Hi,
>
> I'm trying to get a composition working in which I'm having trouble
> getting my entity back from the Response even though the actual service
> request seems to have succeeded. I'm using Jersey 2.5.1 and am using the
> client API to have one service call another 2 services and then do some
> processing based on the results of the 2 composed services.
>
> I'm having no trouble getting the two services being composed to work,
> marshaling the POJO service payload as JSON. If I call either service in a
> browser they both work and spit out the appropriate JSON content.
> Additionally, when I call them from within the composing service, it
> appears that the calls have succeeded. Printing the Response via a logger
> shows the following:
>
> svcResponse: InboundJaxrsResponse{ClientResponse{method=GET, uri=
> http://localhost:8080/v1.1/rs/foobar/1, status=200, reason=OK}}
>
> Additionally, if I call (Response) svcResponse.hasEntity() I get a result
> of true.
>
> However, when I try to call readEntity(), I get a class cast exception:
>
> java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to com.baz.domain.FooBar
>
>
> A few details of my implementation that may be relevant are that we are
> using an application class that subclasses ResourceConfig (without a
> web.xml). This app class also uses the following package scanning call to
> find our annotated classes:
>
> packages("com.baz.rest");
>
> The POJO domain model classes being returned are not in that package, as
> the above snippet of stacktrace shows, but they are being marshaled to JSON
> without issue, so I suspect that's not a problem.
>
> I'm not registering any JSON provider, but have the following in my
> pom.xml which seems to have enabled Jackson:
>
> <dependency>
> <groupId>com.fasterxml.jackson.core</groupId>
> <artifactId>jackson-databind</artifactId>
> <version>${jackson.version}</version>
> </dependency>
>
> <dependency>
> <groupId>com.fasterxml.jackson.core</groupId>
> <artifactId>jackson-annotations</artifactId>
> <version>${jackson.version}</version>
> </dependency>
>
> I have also tried using the following in my pom.xml but it seems to make
> no difference whether it's present or not:
>
> <dependency>
> <groupId>org.glassfish.jersey.media</groupId>
> <artifactId>jersey-media-json-jackson</artifactId>
> </dependency>
>
> It is necessary for compilation if I explicitly register the
> JacksonFeature, but seems to have no effect otherwise.
>
> I'm using a simple unadorned client created in the composing service (the
> one that is calling the other two services):
>
> Client client = ClientBuilder.newClient();
>
> I'm also creating a webTarget and an invocation in the following manner:
>
> WebTarget webTarget = client.target("http://localhost:8080/v1.1/rs");
> Invocation.Builder invocationBuilder = webTarget
> .path("foobar")
> .path(foobarId.toString())
> .request(MediaType.APPLICATION_JSON_TYPE);
> Response svcResponse = invocationBuilder.get(Response.class);
>
>
> I've tried explicitly enabling Jackson by adding the following call in my
> application subclass:
>
> register(JacksonFeature.class);
>
> and adding a similar call in the client code like this:
>
> Client client = ClientBuilder.newClient().register(JacksonFeature.class);
>
> However, when I configure the server and client that way, the Jackson
> databinding doesn't respect the @JsonIgnore annotations in our domain model
> and suffers a stackoverflow error. Without that explicit configuration, I
> get nice decent sized chunks of JSON which do respect the @JsonIgnore
> annotations in our domain model. I've also tried to switch to the Moxy
> JSON code by adding "register(MoxyJsonFeature.class);" to the application
> class and calling "Client client =
> ClientBuilder.newClient().register(MoxyJsonFeature.class);" in the client
> code but this simply results in 500 errors even when calling the 2 composed
> services in a browser. When I do no configuration in either the
> application subclass or in the client code in the calling service as
> originally shown above, I get the proper JSON representation in a browser
> from each of the two composed services.
>
> The problem occurs when I try to access the entity from the response.
> This first call succeeds:
>
> ResponseEnvelope<FooBar> envelope =
> svcResponse.readEntity(ResponseEnvelope.class);
>
> However, I get the class cast exception referencing a LinkedHashMap (?!?)
> when I try the following call:
>
> FooBar fooBar = envelope.getPayload();
>
> Perhaps the problem is related to our envelope class that has a generic
> domain class embedded in it? However, Jackson has no trouble marshaling
> the ResponseEnvelope to JSON, so why would it fail in the opposite
> direction?
>
> I'm utterly confused (obvious? lol), any help would be *greatly*
> appreciated!
>
> --j
>
>
>