Spring boot - setting default Content-type header if it's not present in request

Question

I'm having the following problem: suppose I sometimes receive POST requests with no Content-type header set. In this case I want to assume that Content-type=application/json by default.

Can I achieve this somehow using spring boot features and not using filters?

Thanks

Solution

As of Spring Boot 2.x, you need to create a class that extends the WebMvcConfigurer interface, e.g.:

@Configuration
class WebMvcConfiguration implements WebMvcConfigurer {
    @Override
    public void configureContentNegotiation( ContentNegotiationConfigurer configurer )
    {
        configurer.defaultContentType( MediaType.APPLICATION_JSON );
    }
}

Under 1.x, you could do the same thing with WebMvcConfigurerAdapter, which is now deprecated.

This will affect both request and response bodies, so if you do not have a "produces" parameter explicitly set, and you wanted something other than application/json, it's going to get coerced to application/json.

Comments

[ESala]

can you add a small code example of how you are using the header?

[radistao]

are talking about request or response content type? Did you try @RequestMapping(consumes = APPLICATION_JSON_VALUE, produces = APPLICATION_JSON_VALUE) ?

[best wishes]

the answer suggested by @radistao will enforce the api to take json only, if you send a xml, api will respond saying this content-type is not supported. So If xml is also acceptable then include xml in the consumes list.

[Sachin Verma]

he is asking if we can modify request to add a Content-Type header if its not sent by client.

[KevinO]

Does this answer your question? How to set the default content type in Spring MVC in no Accept header is provided?

[eis]

this is incorrect. This is equivalent of setting default "Accept" header, not of default "Content-Type" header, so will only impact responses, not requests.