• Jackson Json Serialization Options

Jul 22, 2018  The canonical reference for building a production grade API with Spring. In this quick tutorial, we will analyze the marshalling of entities with no getters and the solution for the Jackson JsonMappingException exception. If you want to dig deeper. Jackson Annotations for JSON (Part 2): Serialization As we continue our journey through Jackson annotations, let's see what you can use in your POJOs to serialize Java objects to JSON.

Making Jackson tolerableJyri-Matti L채hteenm채ki2017-04-03Tags:I believe the 'right way' to do serialization and deserialization is a 'type class based' approach, like what does. Unfortunately the community hasn't given us one in the Java-land.is a widely (?) used JSON serialization libary. Unfortunately it has a few problems, but the good thing is that it provides some ways to make it more tolerable: 1) Serializes all classesBy default all classes are serialized using some default behavior. This is unfortunate. I would like to explicitly define how specific classes are serialized, and get an error if I forget one. Automatic best-effort-serialization should be an opt-in.For many projects it would be valuable to be able to see in the code which classes are possibly serialized. For example, I would never-ever want a Hibernate Entity or a MySecretUserDetails to be serialized.

Prohibiting serialization should be the default, not opt-in.This is how you can make Jackson serialize only classes that you have explicitly provided a serializer, or have marked with an annotation allowing automatic bean serialization:In your com.fasterxml.jackson.databind.ObjectMapper define a new com.fasterxml.jackson.databind.ser.BeanSerializerFactory with an overridden method. AUTODETECTGETTERS, false);configure(MapperFeature. AUTODETECTISGETTERS, false);configure(MapperFeature. AUTODETECTSETTERS, false); 5) Has weird default deserialization behaviorBy default Jackson is fine with missing values for primitive fields.

This is odd, since a primitive (versus an object) clearly indicates a required value. Jackson also accepts numbers for Enum values, which is just nasty.Jackson should, by default, fail when required fields are missing and only accept explicit (or at least sensible) deserialization for enums.This is how you can fix these issues.

Jackson Json Serialization Options

In your ObjectMapper. FAILONNULLFORPRIMITIVES, true);configure(DeserializationFeature. FAILONNUMBERSFORENUMS, true);It feels weird to me that these are already easily configurable, but the defaults are wrong.

6) Has dangerous default serializersSerialization definitions should be explicit. That doesn't mean it should be difficult or verbose to use a serialization library. The library could include the same default serializers, and provide documentation about the one-liner to enable them.Jackson doesn't even seem to have a configuration option to disable default serializers, but this is how you can do it. In your custom BeanSerializerFactory override the following method.

NONNULL);This way I can omit fields by setting them to null. Took me a while to discover this feature.

Sensible default behavior would probably be to raise an error if a null is encountered in serialization, and add a hint of this feature to the error message. 9) Deserialization doesn't fail with missing dataWe already saw how Jackson can be made to fail on missing primitive values, but since optionality should be described with an Option type, Jackson should also fail on missing object values.This is how you can do it. Register a BeanDeserializationModifier in your Modules.