java - Jackson JSON serialization, recursion avoidance by level defining

Question

I use Jackson library for serialization of my pojo objects into JSON representation. For example I have class A and class B:

class A {
  private int id;
  private B b;

  constructors...
  getters and setters
}

class B {
  private int ind;
  private A a;

  constructors...
  getters and setters
}

If I want to serialize object from class A there is certain possibility to get recursion while it is serialized. I know i can stop it by using @JsonIgnore.

Is it possible to limit the serialization by depth-level ?

For example, if the level is 2, the serialization will go this way:

• serialize a, level = 0 (0 < 2 ok) - > serialize
• serialize a.b, level =1 (1 < 2 ok) -> serialize
• serialize a.b.a, level = 2 (2 < 2 not true) -> stop

Thanks in advance.

Answer 1

I recently encountered a similar problem: Jackson - serialization of entities with birectional relationships (avoiding cycles)

So the solution is to upgrade to Jackson 2.0, and add to classes the following annotation:

@JsonIdentityInfo(generator = ObjectIdGenerators.IntSequenceGenerator.class, 
                  property = "@id")
public class SomeEntityClass ...

This works perfectly.