CODEWITHSUNDEEP
jpajpa-2.0eclipselink
Łukasz Woźniczka
Łukasz Woźniczka

Reputation: 1695

Jpa eclipselink bug when try persist collection by another entity

Hello i have got one entity which contains collection of object:

@Entity
public class ResourceType{
   @Id
   public Integer id;

  @ManyToMany(mappedBy = "resourcesTypes")
  private Set<Resource> resources = new HashSet<>();

}

As you see this entity contains collection of Resource

@Entity
public class Resource{

    @OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinTable(name = "RESOURCE_TYPE_CROSS", joinColumns = { @JoinColumn(name = "RESOURCE_ID") }, inverseJoinColumns = { @JoinColumn(name = "RESOURCE_TYPE_ID", referencedColumnName = "ID") })
    private List<ResourceType> resourcesTypes = new ArrayList<>();
}

So i guess if i get all resourceTypes with all resources this collection is in local cache.

But if i try persist resource : 

    @Override
    public ResourcesDTO createResource(ResourcesDTO resource) throws CreateResourceException {

    if (resource.getResourcesTypes().isEmpty()) {
        throw new CreateResourceException("Can not create resouce " + resource.getName()
                + " none resource types is set");                                      
    resourceDAO.create(map(resource));      

    log.debug("Created resource: " + r);
    resource.setId(r.getId());

    return resource

    }

If i perssist Resource with ResourcesTypes and next i will get all ResourceTypes entity manager do not found new Resources. But in my cross table resource_type_cross everything is ok. i will try to do something like that after create new resource:

for(ResourceType rt : resource.getResourceTypes()){
    em.refresh(rt);
}

But its not working properly. After i will restart server everything is fine. But why entity manager do not refresh resource type ??

This is what i use to read all ResourceTypes: 

public ResourceType getAllResourceTypes(){
    em.createQuery("Select n from Resource n left join fetch n.children"); 
    return em.find(ResourceType.class, 0); //0 - ROOT

}

as follow article : http://www.tikalk.com/java/load-tree-jpa-and-hibernate

The Main question is that : create or update entity by one side do not update another, so in my case i create and update resource type by resource entity, but i am using resouce type to get all resource.

Upvotes: 0

Views: 487

Answers (1)

Chris
Chris

Reputation: 21165

First, there is a problem with your ManyToMany mappings. You have made both sides unidirectional accessing the same join table instead of bidirectional. One side should control the mapping, with the other set to mappedby the owning side.

Second, have you flushed or committed the changes when you refresh ResourceTypes? It is probably better to maintain both sides by setting the reference in code rather than query to refresh each and every ResourceType

Upvotes: 2

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