how to globally define the naming convention with Jackson

Question

I'm using Jackson with Spring. I have a few methods like this:

@RequestMapping(value = "/myURL", method = RequestMethod.GET)
public @ResponseBody Foo getFoo()  {
    // get foo
    return foo;
}

The class Foo that's serialized is quite big and has many members. The serialization is ok, using annotation or custom serializer.

The only thing I can't figure out is how to define the naming convention. I would like to use snake_case for all the serializations.

So how do I define globally the naming convention for the serialization?

If it's not possible, then a local solution will have to do then.

Answer 1

Not sure how to do this globally but here's a way to do it at the JSON object level and not per each individual property:

@JsonNaming(PropertyNamingStrategy.SnakeCaseStrategy.class)
public class Foo {
    private String myBeanName;
    //...
}

would yield json:

{
    "my_bean_name": "Sth"
    //...
}

Answer 2

Actually, there was a really simple answer:

@Bean
public Jackson2ObjectMapperBuilder jacksonBuilder() {
    Jackson2ObjectMapperBuilder b = new Jackson2ObjectMapperBuilder();
    b.propertyNamingStrategy(PropertyNamingStrategy.SNAKE_CASE);
    return b;
}

I added it in my main like so:

@SpringBootApplication
public class Application {
    public static void main(String [] args) {
        SpringApplication.run(Application.class, args);
    }

    @Bean
    public Jackson2ObjectMapperBuilder jacksonBuilder() {
        Jackson2ObjectMapperBuilder b = new Jackson2ObjectMapperBuilder();
        b.propertyNamingStrategy(PropertyNamingStrategy.SNAKE_CASE);
        return b;
    }
}