Jackson: How to add custom property to the JSON without modifying the POJO

by

Jackson 2.5 introduced the @JsonAppend annotation, which can be used to add “virtual” properties during serialization. It can be used with the mixin functionality to avoid modifying the original POJO.

The following example adds an ApprovalState property during serialization:

@JsonAppend(
    attrs = {
        @JsonAppend.Attr(value = "ApprovalState")
    }
)
public static class ApprovalMixin {}

Register the mixin with the ObjectMapper:

mapper.addMixIn(POJO.class, ApprovalMixin.class);

Use an ObjectWriter to set the attribute during serialization:

ObjectWriter writer = mapper.writerFor(POJO.class)
                          .withAttribute("ApprovalState", "Pending");

Using the writer for serialization will add the ApprovalState field to the ouput.

More Related Contents:

  1. Get NPE reading null object field when deserializing using Jackson [closed]
  2. How do I use a custom Serializer with Jackson?
  3. Why when a constructor is annotated with @JsonCreator, its arguments must be annotated with @JsonProperty?
  4. Jackson ObjectMapper – specify serialization order of object properties
  5. Jackson – How to process (deserialize) nested JSON?
  6. How to serialize only the ID of a child with Jackson
  7. Jackson databind enum case insensitive
  8. What is the JSON View class in Jackson and how does it work?
  9. Ignore missing properties during Jackson JSON deserialization in Java
  10. Jackson is not deserialising a generic list that it has serialised
  11. Jackson JSON custom serialization for certain fields
  12. Use class name as root key for JSON Jackson serialization
  13. Jackson JSON serialization, recursion avoidance by level defining
  14. Json deserialization into other class hierarchy using Jackson
  15. Custom Jackson Serializer for a specific type in a particular class
  16. Jackson custom annotation for custom value serialization
  17. Jackson Serialize Instant to Nanosecond Issue
  18. Jackson deserialize based on type
  19. Difference between @JsonIgnore and @JsonBackReference, @JsonManagedReference
  20. org.codehaus.jackson versus com.fasterxml.jackson.core
  21. How to solve circular reference in json serializer caused by hibernate bidirectional mapping?
  22. directly convert CSV file to JSON file using the Jackson library
  23. Jackson – serialization of entities with birectional relationships (avoiding cycles)
  24. How to deserialize JS date using Jackson?
  25. Serializing enums with Jackson
  26. How to map a nested value to a property using Jackson annotations?
  27. How to convert JSON string into List of Java object?
  28. Ignoring property when deserializing
  29. Deserialize JSON into existing object (Java)
  30. JSON Jackson parse different keys into same field

Leave a Comment