Json and Java – Circular Reference

by

There are two ways you can go about this. If you must expose your entity to the outside world, I recommend adding @JsonIgnore on the property that is causing the circular reference. This will tell Jackson not to serialize that property.

Another way is to use the bidirectional features provided by Jackson. You can either use @JsonManagedReference or @JsonBackReference. @JsonManagedReference is the “forward” part of the property and it will get serialized normally. @JsonBackReference is the “back” part of the reference; it will not be serialized, but will be reconstructed when the “forward” type is deserialized.

You can check out the examples here.

This addresses your comment: I think what you might want to do in this case is use a DTO that is visible to the outside world. I like this approach because I don’t want to expose my entities to the outside. This means that the Jackson annotations would be on the DTO and not on the enity. You would need some sort of mapper or converter that converts the entity to the DTO. Now when you make changes to your entity, they won’t get propagated to the DTO unless you modify your mapper/converter. I think this is ok, because when you make a change to your entity you can decide if you want that change to be exposed or not.

UPDATE

There is a good blog post here that goes into detail about the various ways you can handle bidirectional relationships in Jackson. It describes solutions that use @JsonIgnore, @JsonManagedReference and @JsonBackReference, @JsonIdentityInfo, @JsonView and a custom serializer as well. It’s a pretty comprehensive writeup of the various techniques that you can use.

More Related Contents:

  1. How to use @JsonIdentityInfo with circular references?
  2. How to use Jackson to deserialise an array of objects
  3. Java 8 LocalDate Jackson format
  4. Jackson – Deserialize using generic class
  5. Different names of JSON property during serialization and deserialization
  6. Date format Mapping to JSON Jackson
  7. Deserialize JSON with Jackson into Polymorphic Types – A Complete Example is giving me a compile error
  8. Jackson serialization: ignore empty values (or null)
  9. Parsing JSON in Java without knowing JSON format
  10. Jackson JSON Deserialization with Root Element
  11. Jackson Change JsonIgnore Dynamically
  12. Query a JSONObject in java
  13. How to create a custom deserializer in Jackson for a generic type?
  14. JPA Transient Annotation and JSON
  15. How to convert XML to JSON using only Jackson?
  16. How to enforce ACCEPT_SINGLE_VALUE_AS_ARRAY in jackson’s deserialization process using annotation
  17. Removing JSON elements with jackson
  18. Jackson – Required property?
  19. Jackson @JsonProperty(required=true) doesn’t throw an exception
  20. JSON to JSON transformer
  21. Jsonpath with Jackson or Gson
  22. Jackson JSON serialization, recursion avoidance by level defining
  23. Json deserialization into other class hierarchy using Jackson
  24. Jackson ObjectMapper DeserializationConfig.Feature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT
  25. JSON Jackson parse different keys into same field
  26. What’s the Jackson deserialization equivalent of @JsonUnwrapped?
  27. Jackson JSON Deserialization: array elements in each line
  28. How to use dynamic property names for a Json object
  29. Order of JSON objects using Jackson’s ObjectMapper
  30. Parsing json into java objects in spring-mvc

Leave a Comment