Having difficulty using Envers to audit a many-to-many relation

Question

I'm wanting to use Envers to audit a many-to-many relation with an embedded component but I'm having trouble with a MappingException saying the the ComponentType is not supported. This is relevant portion of the stack trace:

Caused by: org.hibernate.MappingException: Type not supported: org.hibernate.type.ComponentType
        at org.hibernate.envers.configuration.metadata.IdMetadataGenerator.addIdProperties(IdMetadataGenerator.java:74)
        at org.hibernate.envers.configuration.metadata.IdMetadataGenerator.addId(IdMetadataGenerator.java:105)
        at org.hibernate.envers.configuration.metadata.AuditMetadataGenerator.generateFirstPass(AuditMetadataGenerator.java:413)
        at org.hibernate.envers.configuration.EntitiesConfigurator.configure(EntitiesConfigurator.java:101)
        at org.hibernate.envers.configuration.AuditConfiguration.<init>(AuditConfiguration.java:103)
        at org.hibernate.envers.configuration.AuditConfiguration.getFor(AuditConfiguration.java:135)
        at org.hibernate.envers.event.EnversIntegrator.integrate(EnversIntegrator.java:63)
        at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:295)
        at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1737)
        at org.hibernate.ejb.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:76)
        at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:905)

Reading the Envers reference, it appears that Envers can handle what I'm trying to do. According to the reference:

If you'd like to override auditing behaviour of some fields/properties inherited from @Mappedsuperclass or in an embedded component, you can apply the @AuditOverride(s) annotation on the subtype or usage site of the component.

Here's my association entity. You can see where I tried to use @AuditOverride at the class level to prevent auditing the embedded component. I also tried using the annotation on the field itself. Neither made a difference.

@Audited
//  @AuditOverride(name = "pk", isAudited = false) <===== Didn't help
@Table(name = "user_role")
@javax.persistence.Entity
@AssociationOverrides
(
    {
    @AssociationOverride
        (name = "pk.user", joinColumns = @JoinColumn(name = "id")),
    @AssociationOverride
        (name = "pk.role", joinColumns = @JoinColumn(name = "id"))
    }
)
public class UserRole extends Entity<UserRole>
{
    private static final long serialVersionUID = 1L;

    private Date expirationDate;
    private UserRolePk pk = new UserRolePk();

    public UserRole() {}

    //  @AuditOverride(name = "pk", isAudited = false) <== Didn't help
    @EmbeddedId
    public UserRolePk getPk() { return pk; }

    @Transient
    public User getUser() { return getPk().getUser(); }

    @Transient
    public Role getRole() { return getPk().getRole(); }
...
}

Here's the user entity:

@Audited
@Table(name = "applicationuser")
@javax.persistence.Entity
public class User extends Entity<User>
{
    private static final long serialVersionUID = 1L;
    private String firstName;
    private String lastName;
    private String email;
    private Set<UserRole> userRoles = new HashSet<UserRole>(0);

    @OneToMany(fetch = FetchType.LAZY, cascade=CascadeType.ALL,
        mappedBy = "pk.user", orphanRemoval = true)

    public Set<UserRole> getUserRoles() { return userRoles; }
...
}

Here's the role entity:

@Audited
@Table(name = "role")
@javax.persistence.Entity
public class Role extends Entity<Role>
{
    private static final long serialVersionUID = 1L;
    private String name;
    private String label;
    private Set<UserRole> userRoles = new HashSet<UserRole>(0);

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "pk.role",
        cascade=CascadeType.ALL, orphanRemoval = true)

    public Set<UserRole> getUserRoles() { return userRoles; }
...
}

Here's the embedded component:

@Embeddable
public class UserRolePk implements Serializable
{
    private static final long serialVersionUID = 1L;

    private User user;
    private Role role;

    @ManyToOne
    public User getUser() { return user; }

    @ManyToOne
    public Role getRole() { return role; }
...
}

And finally, here is my base entity, for completeness:

@MappedSuperclass()
public abstract class Entity<X extends Entity<X>>
    implements Comparable<X>, Serializable
{
    private static final long serialVersionUID = 1L;
    private Long id;
    private Timestamp timestamp;
...
}

I've read the Envers reference and perused the forum, but the information seems pretty sparse. Any ideas or pointers on this?

Answer 1

I'm using Envers 4.1.3.Final and it definitely still has this bug: for relationships to @Embedded components it logs the audit record correctly in the database, but the query API (forRevisionsOfEntity, in my case) simply doesn't see it. It would return a revision (MOD) for the changed object, but when you look in the actual entity property that holds the reference to the embedded object, it is always null, for all revisions.

I ended up writing a workaround to query the changed values with native SQL (for the affected properties), since I didn't feel like changing my mapping just to appease a buggy plugin.

Answer 2

I resolved this by discarding the embeddable component, UserRolePk, and just going with @JoinColumn e.g.

public class UserRole extends Entity<UserRole>
{
    private User user;
    private Role role;

    public UserRole() {}

    @ManyToOne(fetch=FetchType.EAGER, optional=false)
    @JoinColumn(name="userid", referencedColumnName = "id", insertable=false, updatable=false)
    // XmlTransient used to prevent the following exception when JAXB marshals this into XML:
    //  com.sun.istack.SAXException2: A cycle is detected in the object graph. This will cause
    //  infinitely deep XML:
    @XmlTransient
    public User getUser() { return this.user; }

    @ManyToOne(fetch=FetchType.EAGER, optional=false)
    @JoinColumn(name="roleid", referencedColumnName = "id", insertable=false, updatable=false)
    public Role getRole() { return this.role; }
...
}