using model classes with association for serialization and deserialization with jackson - spring-boot

Question

I have three classes with associations as follows:
Process.java
#Getter
#Setter
#NoArgsConstructor
#AllArgsConstructor
#JsonIdentityInfo(generator = ObjectIdGenerators.UUIDGenerator.class)
public class Process {
private UUID processId;
private List<User> users = new ArrayList<>();
private List<UnitType> units = new ArrayList<>();
private String furtherComment;
private List<AnsweredQuestionnaire> answeredQuestionnaires = new ArrayList<>()
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (!(o instanceof Process)) return false;
Process process = (Process) o;
return getProcessId().equals(process.getProcessId());
}
#Override
public int hashCode() {
return Objects.hash(getProcessId());
}
}
AnsweredQuestionnaire.java
#Setter
#Getter
#NoArgsConstructor
#AllArgsConstructor
public class AnsweredQuestionnaire {
private UUID answeredQuestionnaireId;
private Questionnaire questionnaire;
private Process process;
public void addProcessToAnsweredQuestionnaire(Process process){
//remove old association
if(this.process != null){
this.process.getAnsweredQuestionnaires().remove(this);
}
this.process = process;
//add new association
if(process != null){
this.process.getAnsweredQuestionnaires().add(this);
}
}
}
User.java
#Setter
#Getter
#NoArgsConstructor
#AllArgsConstructor
public class User {
private UUID userId;
private String firstName;
private String lastName;
private String phoneNumber;
private String email;
private List<Role> roles = new ArrayList<>();
private List<Process> processes = new ArrayList<>();
public void addProcessToUser(Process process){
this.processes.add(process);
process.getUsers().add(this);
}
public void removeProcessFromUser(Process process){
this.processes.remove(process);
process.getUsers().remove(this);
}
}
I have to use these classes for serialization and deserialization using objectMapper. I dont know the proper way to use the #JsonIdentityInfo annotation. Could someone please suggest me how to implement this. With the work done above I get circular dependency issues.

Answer 1

Use #JsonBackReference (on the List property) and #JsonManagedReference (on the object property) annotations for avoid the circular reference on serialization.