Resttemplate - how to post object with HAL representation? - spring

Question

When attempting to post to a Spring-Data-Rest web service via RestTemplate, the JSON representation of my domain object is being converted to a full blown JSON object that isn't in HAL representation. My assumption here is that I need to register the Jackson2HalModule as a deserializer though am not sure how to do that considering I register it to the objectMapper. The serialization works correctly when calling GET on the webservice, just not for POST/PUT:
Request outputBuffer field:
{
"id" : 1,
"name" : "Name",
"description" : "",
"childObject" : {
"id" : 1,
"name" : "test"
}
}
Rest Template configuration:
#Bean
public ObjectMapper objectMapper() {
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.registerModule(new JodaModule());
objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
objectMapper.setDateFormat(new ISO8601DateFormat());
objectMapper.enable(SerializationFeature.INDENT_OUTPUT);
objectMapper.registerModule(new Jackson2HalModule());
return objectMapper;
}
public void configureMessageConverters(
List<HttpMessageConverter<?>> messageConverters) {
MappingJackson2HttpMessageConverter jsonMessageConverter = new MappingJackson2HttpMessageConverter();
jsonMessageConverter.setObjectMapper(objectMapper());
jsonMessageConverter.setSupportedMediaTypes(MediaType
.parseMediaTypes("application/hal+json,application/json"));
messageConverters.add(jsonMessageConverter);
}
#Bean
public RestTemplate restTemplate() {
RestTemplate restTemplate = new RestTemplate();
List<HttpMessageConverter<?>> messageConverters = new ArrayList<>();
configureMessageConverters(messageConverters);
restTemplate.setMessageConverters(messageConverters);
return restTemplate;
}
Request Headers:
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
Calling method:
ResponseEntity<DomainObject> responseEntity =
restTemplate.exchange(this.getBaseUri() + resolveResource(), HttpMethod.POST, new HttpEntity(domainObject,createHttpHeaders(tenantId)), DomainObject.class);

Answer 1

I think you should not register your own ObjectMapper. Spring creates it for you and also registers all the modules needed. So I would just try to remove your ObjectMapper bean.
If you need to customize the ObjectMapper you could use a Jackson2ObjectMapperBuilder. See the documentation for more details - http://docs.spring.io/spring-boot/docs/current-SNAPSHOT/reference/htmlsingle/#howto-customize-the-jackson-objectmapper
#Bean
public Jackson2ObjectMapperBuilder jackson2ObjectMapperBuilder() {
return Jackson2ObjectMapperBuilder //
.json() //
.locale(ENGLISH) //
.timeZone("UTC") //
.indentOutput(true) //
.serializationInclusion(NON_NULL) //
.featuresToDisable(WRITE_DATES_AS_TIMESTAMPS, FAIL_ON_UNKNOWN_PROPERTIES) //
;
}
I would also let spring take care of the message converters:
So let spring inject them when you create the RestTemplate - so something like this:
#Bean
public RestTemplate restTemplate(List<HttpMessageConverter<?>> messageConverters) {
RestTemplate restTemplate = new RestTemplate();
restTemplate.setMessageConverters(messageConverters);
return restTemplate;
}