Direct self-reference leading to cycle exception

Question

I have a class; something like the following:

public abstract class ElasticSearchValue {

  private Long txId;
  private Long currentTxId;
  private         


        

Answer 1

Try @JsonIdentityInfo annotation as given in this example. More details here http://wiki.fasterxml.com/JacksonFeatureObjectIdentity

@JsonIdentityInfo(generator=ObjectIdGenerators.IntSequenceGenerator.class, property="@id")
public class Identifiable
{
    public int value;

    public Identifiable next;
}

Answer 2

I guess somewhere in your code. The previous of some instance of DailyActivity point to itself.

Answer 3

The self-reference is here:

public class DailyActivity extends ElasticSearchValue<DailyActivity> {

You're saying DailyActivity is an ElasticSearchValue<DailyActivity>, which is by itself an ElasticSearchValue<ElasticSearchValue<DailyActivity>>, and this goes on infinitely...

Update: I would break that in two classes. Create DailyActivity without subclassing ElasticSearchValue:

public class DailyActivity {
  // the same content as your class above

then create another class like:

public class ElacticDailyActivity extends ElasticSearchValue<DailyActivity> {

Answer 4

In this case you need to annotate the relationships with @JsonManagedReference and @JsonBackReference like this:

 @ManyToOne
 @JoinColumn(name = "company_id", referencedColumnName = "id")
 @JsonBackReference
 private Company company 

And

 @OneToMany(mappedBy="company")
 @JsonManagedReference
 private Set<Employee> employee = new HashSet<Employee>();

There is a nice example here

Answer 5

SerializationFeature has a property called FAIL_ON_SELF_REFERENCES default is true but you can set to false to skip this kind of exception.

    ObjectMapper objectMapper = new ObjectMapper();
    objectMapper.configure(SerializationFeature.FAIL_ON_SELF_REFERENCES, false);

If you are using SpringBoot you can simply add spring.jackson.serialization.fail-on-self-references=false in your application.properties