Immutable Lombok annotated class with Jackson

Question

What is the preferred way to create class that is

• Immutable
• Can be serialized/deserialized with Jackson
• Human-readable and with low level of boilerplate

Preferably, I would have liked something like this to work:

@Data(onConstructor = @__(@JsonCreator)) 

and then have all fields to be private final. However, this does not even compile (and I'm not sure why). Using

@AllArgsConstructor(onConstructor = @__(@JsonCreator)) 

will compile but only yields

InvalidDefinitionException: No serializer found for class 

Answer 1

add ConstructorProperties:

• Create a lombok.config file in an appropriate location with the line: lombok.anyConstructor.addConstructorProperties = true
• Add lombok @Value annotation to your class to make it immutable

Then serialization and deserialization by Jackson works as expected.

This method:

• meets the criteria
• has less boilerplace than the previous top answer
• works on v1.16.20 (January 9th, 2018) and later

Edit: 2020-08-16

• Note: Using @Builder with @Value causes this solution to fail. (Thanks to comment from @guilherme-blanco below.) However, if you also add e.g. @AllArgsConstructor it does still work as expected.

Edit: 2021-08-19

• Note: When you add or change a lombok.config file the change is not picked up unless you do a rebuild (clean then build). I have been caught out by this a few times.
• @Jacksonized annotation solution is another method to achieve the desired outcome for the specific classes annotated. However, I personally prefer not to need to remember to annotate every class used for deserialization. Using lombok.config removes this overhead.

Answer 2

As of 15 October 2020 (Lombok v1.18.16), you should simply be able to use the @Jacksonized annotation.

@Jacksonized @Builder @JsonIgnoreProperties(ignoreUnknown = true) public class JacksonExample {   private List<Foo> foos; } 

As described in the linked documentation, this annotation:

• configures Jackson to use the builder for deserialisation,
• copies field-specific configuration down from the annotated class to the generated builder (e.g. @JsonIgnoreProperties), and
• aligns the Jackson prefix used on builder methods (e.g. builder().withField(field) vs builder.field(field) to the one configured in Lombok.