How was model looping handled?

Model cyclicity is a situation where model objects refer to each other cyclically, which can lead to infinite recursion during traversal or serialization.

To handle such cycles, the following approaches are usually used:

• Using identifiers instead of nested objects during serialization to break the cycles.
• Limiting the depth of model traversal.
• Applying specialized libraries that can recognize cycles and handle them correctly (for example, Jackson with @JsonIdentityInfo annotations).

An example with Jackson to prevent infinite recursion:

@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "id")
public class User {
    private Long id;
    private User manager;
    // getters and setters
}

Thus, during serialization, references to already serialized objects are replaced with their identifiers, preventing cyclicity.