Has anyone working with Spring-Boot figured out how to override the default Jackson ObjectMapper that is automatically configured? I have tried to instantiate both the ObjectMapper as a bean and within a MappingJackson2HttpMessageConverter also as a been. But with no success...
Any thoughts?
Spring handles HTTP #ResponseBody using the HttpMessageConverter abstraction, so it's there that you would have to add customizations. Normally you would add a #Bean extending WebMvcConfigurerAdapter and override the configureMessageConverters() method.
Adding a #Bean of type ObjectMapper sounds like a neat way to do this for a Spring Boot application, so you could provide that feature in a pull request if you like.
Related
i am using spring-boot 3.0.2 and have created a custom jackson serializer and registered it using #JsonComponent. i have confirmed it is registered in the ObjectMapper instance that gets injected using #Autowire. when i go to invoke the rest endpoint that will return an object that should be handled by the custom serializer, it is never by the RequestResponseBodyMethodProcessor.
after doing some digging it seems only the default set of converters created in WebMvcConfigurationSupport are being used and nothing else. i have tried registering my own instance of MappingJackson2HttpMessageConverter as a #Bean but it is never used.
the only way i have found to fix this issue is to replace whatever default is being created using extendMessageConverters in WebMvcConfigurer.
can anyone offer any suggestions? from the various blog posts i've read, this should just work but appears not to.
i expect json that looks like this:
["fqdn":"test.com"]
but instead get:
["fqdn:{"idnEncoded":false,"domainName":"test","tldName":"com"}]
I have created a custom Webclient Builder instead of injecting the default builder.
#Configuration
public class WebClientConfig() {
#Bean(name = "myWebClientBuilder")
public Webclient.Builder customBuilder() {
return WebClient.builder();
}
}
I have multiple services where I use this bean myWebClientBuulder and do further customization with chain of ExchangeFilterFunction.
This might not be the recommended way of using the WebClient but I would like to get some insight if there is a way to get the downstream call metrics from the Webclient based on this configuration.
Actuator Endpoint: actuator/metrics/http.client.requests
Spring Boot auto-configured WebClient.Builder is way powerful than customized version.
I tried to configure the custom builder in WebClientConfig() but it started to structure just like a copy version of WebClientAutoConfiguration. I ended up going with the spring boot autoconfigured WebClient.Builder bean.
If it helps, you can study how WebClientAutoConfiguration tries to configure webClient customizers. For metrics, it would be MetricsWebClientCustomizer.
We have many Spring MVC projects already, which all use gson instead of jackson for response body encode. Our bean classes are all written based on gson annotation. Now I am setting up a Spring Webflux restful server. It would save a lot of work if we can use the old bean classes from our Spring MVC projects.
I have tried spring.http.converters.preferred-json-mapper=gson property to no avail.
I have tried HttpMessageConverter bean, which is included in webflux packages, but that does not work as in the Spring MVC projects.
I googled a lot and the only thing helpful is to implement org.springframework.http.codec.HttpMessageEncoder class and set it to WebFluxConfigurer.configureHttpMessageCodecs() method:
#Configuration
public class WebConfiguration implements WebFluxConfigurer {
#Override
public void configureHttpMessageCodecs(ServerCodecConfigurer configurer) {
configurer.customCodecs().decoder(new GsonHttpMessageDecoder());
configurer.customCodecs().encoder(new GsonHttpMessageEncoder());
}
private static class GsonHttpMessageEncoder implements HttpMessageEncoder {
...
}
private static class GsonHttpMessageDecoder implements HttpMessageDecoder {
...
}
}
I haven't try this out yet, since it is a little complex. Is there some easy way to replace jackson with gson in Spring Webflux?
Any help is appreciated.
Spring Framework doesn't support GSON as a WebFlux Encoder / Decoder for now. Feel free to follow up on the dedicated issue.
Note that as far as I know, GSON doesn't support non-blocking parsing so even if the support is implemented in Framework, it won't be complete and should not cover streaming input use cases.
I have a small module that should only contain the resource model of my REST service. I want to create a test in this module to ensure that the resource model serializes and deserializes appropriate HAL format.
I have a single test and this is the configuration:
#RunWith(SpringRunner::class
#SpringBootTest
#AutoConfigureJsonTesters
class MyTest {
#Autowired
private lateinit var collectionTester: JacksonTester<Resources<Entity>>
....
}
and a very simple configuration
#SpringBootConfiguration
class TestConfig
When calling collectionTester.write on a list of Entity (which extends ResourceSupport) I don't get an _embedded field, instead I get
{"links":[],"content":[...]}
which is not HAL format.
How can I force #AutoConfigureJsonTesters to give me a JacksonTester with an ObjectMapper configured for HAL?
Spring Boot 2.0.0.RELEASE
Thanks!
The auto-configured JacksonTester will use the context’s ObjectMapper which won’t have any of the Spring HATEOAS stuff configured on it. You might be better creating a JacksonTester yourself and passing it an appropriately configured ObjectMapper to use.
I believe Spring HATEOAS has a module that it applies to the ObjectMapper to configure it. If you get stuck with that, asking in gitter/spring-projects/spring-data is probably your best bet as Spring HATEOAS is maintained by the Data team due to it being used by Spring Data REST.
The JacksonAutoConfiguration initializes an ObjectMapper with the JSR310Module registered. Then HttpMessageConvertersAutoConfiguration initializes a MappingJackson2HttpMessageConverter. But this MessageConverter never gets plugged in the RequestResponseBodyMethodProcessor.
As a result:
If the controller returns a object which should be jsonified by Jackson, dates are poorly converted because the wrong MappingJackson2HttpMessageConverter is used (initialized in WebMvcConfigurationSupport#addDefaultHttpMessageConverters)
But, if the ObjectMapper is injected in the controller and used to jsonify the same object, then the date format is alright.
How can I can wake the WebMvcAutoConfigurationAdapter up? What should I do to bind the configured Jackson ObjectMapper with Spring MVC and make it handle response bodies?
If you use #EnableWebMvc that would explain your symptoms So the rule thumb is: do not use #EnableWebMvc with Spring Boot, unless you wan't to customize Web MVC configuration?