[FIXED] How to customize Jackson ObjectMapper with Spring application.properties?

Issue

I want to enable the following jackson mapper feature: MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES

According to https://docs.spring.io/spring-boot/docs/current/reference/html/howto-spring-mvc.html:

Could be configured in application.properties as follows: spring.jackson.mapper.accept_case_insensitive_properties=true

But:

@RestController
public class MyServlet {
    @RequestMapping("/test")
    public void test(@Valid TestReq req) {

    }
}

public class TestReq {
    @NotBlank
    private String name;
}

Usage:

localhost:8080/test?name=test //works
localhost:8080/test?Name=test //fails with 'name may not be blank'

So, the case insensitive property is not taken into account. But why?

By the way: even using Jackson2ObjectMapperBuilderCustomizer explicit does not work:

@Bean
public Jackson2ObjectMapperBuilderCustomizer initJackson() {
    Jackson2ObjectMapperBuilderCustomizer c = new Jackson2ObjectMapperBuilderCustomizer() {
        @Override
        public void customize(Jackson2ObjectMapperBuilder builder) {
            builder.featuresToEnable(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES);
        }
    };

    return c;
}

spring-boot-1.5.3.RELEASE

Solution

Simple answer: it is not possible.

The Jackson2ObjectMapperBuilderCustomizer affects the JSON POST requests only. It has no effect on the get query binding.

Answered By - membersound