NullPointerException at org.hibernate.ejb.criteria.path.AbstractPathImpl.get

Question

This works fine:

 public Predicate toPredicate(Root<Campaign> root,
    CriteriaQuery<?> query, CriteriaBuilder cb) {
    return root.get("campState").get("statusId").in(campStatus);
}

but I change to ：

 return  root.get(Campaign_.campState).get(CampState_.campId).in(campStatus).

And it throws exception：

edit for: NullPointerException at org.hibernate.ejb.criteria.path.AbstractPathImpl.get

  @StaticMetamodel(Campaign.class)
  public class Campaign_ {
  public static volatile SingularAttribute<Campaign, CampState> campState;
  public static volatile SingularAttribute<Campaign, Long> campId;
  }

  @StaticMetamodel(CampState.class)
  public class CampState_ {
  public static volatile SingularAttribute<CampState, String> statusId;
  }

  Campaign.class
  @ManyToOne(cascade = {CascadeType.REFRESH, CascadeType.MERGE})
  @JoinColumn(name = "camp_status")
  public CampState getCampState() {
    return campState;
  }

  public void setCampState(CampState campState) {
    this.campState = campState;
  }

java.lang.NullPointerException at com.yunat.ccms.biz.core.specification.CampaignSpecifications$1.toPredicate(CampaignSpecifications.java:24) at — samung88, Feb 18 '13 at 02:14
24 line is return root.get("campState").get("statusId").in(campStatus); — samung88, Feb 18 '13 at 02:14

score 2 · Answer 1 · edited May 23 '17 at 11:46

2

check this answer.

seems like metamodel and class should be at the same package

edited May 23 '17 at 11:46

Community

1
1

answered Nov 20 '13 at 13:52

oak

2,898
2
32
65

The "package solution" was just an assumption and has no explanation why nor how it fixes the issue. – Mr.Mountain Aug 25 '17 at 06:16
the `meta model` and the `class` should be at the same package....this is a requirement – oak Aug 26 '17 at 16:52

score 0 · Answer 2 · answered Aug 18 '13 at 17:42

Given two queries operate to different attributes. Second query cannot be compiled, because CampState_ does not have attribute campId (Campaign_ does have such a attribute.

Query that is equivalent to first one with static metamodel is:

root.get(Campaign_.campState).get(CampState_.statusId).in(campStatus).

NullPointerException at org.hibernate.ejb.criteria.path.AbstractPathImpl.get

2 Answers2

Linked