I'm trying to marshal response containing ISO formatted timestamp like that:
{
...
"time" : "2014-07-02T04:00:00.000000Z"
...
}
into ZonedDateTime
field in my domain model object. Eventually it works if I use solution that is commented in following snippet.There are many similar questions on SO but I would like to get a specific answer
what is wrong with another approach which uses JacksonJsonProvider
with ObjectMapper + JavaTimeModule
?
ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new JavaTimeModule());
JacksonJsonProvider provider = new JacksonJsonProvider(mapper);
Client client = ClientBuilder.newBuilder()
// .register(new ObjectMapperContextResolver(){
// @Override
// public ObjectMapper getContext(Class<?> type) {
// ObjectMapper mapper = new ObjectMapper();
// mapper.registerModule(new JavaTimeModule());
// return mapper;
// }
// })
.register(provider)
.register(JacksonFeature.class)
.build();
Error I get:
javax.ws.rs.client.ResponseProcessingException: com.fasterxml.jackson.databind.JsonMappingException: Can not construct instance of java.time.ZonedDateTime: no String-argument constructor/factory method to deserialize from String value ('2017-02-24T20:46:05.000000Z')
at [Source: org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$UnCloseableInputStream@53941c2f
Project dependencies are:
compile 'com.fasterxml.jackson.datatype:jackson-datatype-jdk8:2.8.7'
compile 'com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.8.7'
compile 'com.fasterxml.jackson.core:jackson-core:2.8.7'
compile 'com.fasterxml.jackson.core:jackson-databind:2.8.7'
compile 'com.fasterxml.jackson.core:jackson-annotations:2.8.7'
compile 'org.glassfish.jersey.core:jersey-client:2.25.1'
edit
Deserialization happens in here:
CandlesResponse<BidAskCandle> candlesResponse = webTarget.request()
.header(HttpHeaders.AUTHORIZATION,"Bearer "+token)
.accept(MediaType.APPLICATION_JSON)
.get(new GenericType<CandlesResponse<BidAskCandle>>(){});
Eventually it works if I use solution that is commented in following snippet.
First of all, you are missing a dependency in your list, that you also have, which is the problem.
jersey-media-json-jackson
This module depends on the native Jackson module that has the JacksonJsonProvider
. When you register the JacksonFeature
(that comes with jersey-media-json-jackson
), it registers its own JacksonJaxbJsonProvider
, which seems to take precedence over any that you provide.
When you use the ContextResolver
, the JacksonJsonProvider
actually looks-up that ContextResolver
and uses it to resolve the ObjectMapper
. That's why it works. Whether you used the JacksonFeature
or registered your own JacksonJsonProvider
(without configuring an ObjectMapper
for it) the ContextResovler
would work.
Another thing about the jersey-media-json-jackson
module, it that it participates in Jersey's auto-discoverable mechanism, which registers it's JacksonFeature
. So even if you didn't explicitly register it, it would still be registered. The only ways to avoid it being registered are to:
Disable the auto-discovery (as mention in the previous link)1
Don't use the jersey-media-json-jackson
. Just use the Jackson native module jackson-jaxrs-json-provider
. Thing about this though is that, the jersey-media-json-jackson
adds a couple features on top of the the native module, so you would lose those.
Haven't tested, but it seems that if you use JacksonJaxbJsonProvider
instead of JacksonJsonProvider
, it might work. If you look at the source for the JacksonFeature
, you will see that it checks for an already registered JacksonJaxbJsonProvider
. If there is one, it won't register it's own.
The one thing I'm not sure about with this is the auto-discoverable. The order in which it is registered, if it will affect whether or not it catches your registered JacksonJaxbJsonProvider
. Something you can test out.
1. See also
From my pet project:
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-jsr310</artifactId>
<version>${jackson.version}</version>
</dependency>
public WebTarget getTarget(URI uri) {
Client client = ClientBuilder
.newClient()
.register(JacksonConfig.class);
return client.target(uri);
}
where
@Provider
public class JacksonConfig implements ContextResolver<ObjectMapper> {
private final ObjectMapper objectMapper;
public JacksonConfig() {
objectMapper = new ObjectMapper();
objectMapper.registerModule(new JavaTimeModule());
objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
}
@Override
public ObjectMapper getContext(Class<?> aClass) {
return objectMapper;
}
}
Jackson configuration looks fine, I tried the following and was able to deserialize the value:
public class Test {
public static void main(String[] args) throws Exception {
ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new JavaTimeModule());
Model model = mapper.readValue("{\"time\" : \"2014-07-02T04:00:00.000000Z\"}", Model.class);
System.out.println(model.getTime());
}
}
class Model{
private ZonedDateTime time;
public ZonedDateTime getTime() {
return time;
}
public void setTime(ZonedDateTime time) {
this.time = time;
}
}
I can reproduce it by commenting out mapper.registerModule(new JavaTimeModule());
. So, it looks like jersey client is not using custom mapper
instance. Could you try configuring it as described here.
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