Failed to lazily initialize role collection in ManyToMany relationship despite using JsonIgnore

I have two business objects that have too many relationships. I am using a REST service to call the DAO method below and get a list of political indicators for a political event. However, while piList in DAO successfully gives me a list of political indicators, it still gives me an exception.

Failed to lazily intialize a collection of role...

via link chain:

org.hibernate.collection.internal.PersistentBag[0]----->PolIndicator.piList.role
org.jboss.resteasy.spi.writerException
org.codehaus.jackson.map.JsonmappingException"

      

        
        
        
      

    

I used @JsonIgnore

in class "Political Indicator" against the property of a political event, but there is still a lazy exception.

Where am I going wrong?

PolEvent {

    @Id
    @Column(name="SEQ_EVENT_ID")
    private BigDecimal id;

    @Column(name="EVENT_NAME")
    private String eventName;

    @ManyToMany
    @JoinTable(
        name="POL_LINK_INDCTR"
        joinColumns={@JoinColumn(name="SEQ_EVENT_ID")},
        inverseJoinColumns=@JoinColumn(name="SEQ_PI_ID")
    )
    private List <PolIndicator> piList;
}


PolIndicator {

    @Id
    @Column(name="SEQ_PI_ID")
    private BigDecimal id;

    @Column(name="POL_IND_NAME")
    private String piName;

    @ManyToMany(mappedBy="piList")
    @JsonIgnore
    private List <PolEvent> eventList; 
}

      

        
        
        
      

    

DAO level code

public List <PolIndicator> getPiList (String eventId) {

    Criteria criteria = session.createCriteria(PolEvent.class);
    criteria.add(Restrictions.eq("id",id);
    PolEvent polEvent = new PolEvent();
    polEvent=criteria.uniqueResult();
    piList = polEvent.getPiList();
    return piList();
}