How to configure Jackson in spring boot application without overriding springs default setting in pure java

Question

In my spring boot application i am using Jackson to serialize objects by injecting the ObjectMapper where needed. I found this answer: https://stackoverflow.com/a/32842962/447426 But this one creates a new mapper - with jacksons default settings.

On the other hand i found this in official docu. I didn't really understand. There is no example code.

So how to configure springs ObjectMapper on base of Spring's default object mapper?

This configuration should be active on "ObjectMapper" whereever injected.

Answer 1

You should use Jackson2ObjectMapperBuilderCustomizer for this

@Configuration
public class JacksonConfiguration {

    @Bean
    public Jackson2ObjectMapperBuilderCustomizer addCustomBigDecimalDeserialization() {
        return new Jackson2ObjectMapperBuilderCustomizer() {

            @Override
            public void customize(Jackson2ObjectMapperBuilder jacksonObjectMapperBuilder) {
               jacksonObjectMapperBuilder.featuresToDisable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
               // Add your customization
               // jacksonObjectMapperBuilder.featuresToEnable(...)      
            }
        };
    }
}

---

Because a Jackson2ObjectMapperBuilderCustomizer is a functor, Java 8 enables more compact code:

@Configuration
public class JacksonConfiguration {

    @Bean
    public Jackson2ObjectMapperBuilderCustomizer addCustomBigDecimalDeserialization() {
        return builder -> {
            builder.featuresToDisable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
            // Add your customization
            // builder.featuresToEnable(...)      
            };
        }
    }
}