[ http://opensource.atlassian.com/projects/hibernate/browse/ANN-381?page=co... ] Brice Laurencin commented on ANN-381: ------------------------------------- I can't get this to work. I get an NPE: java.lang.NullPointerException at org.hibernate.cfg.annotations.CollectionBinder.bindManytoManyInverseFk(CollectionBinder.java:1370) at org.hibernate.cfg.annotations.CollectionBinder.bindManyToManySecondPass(CollectionBinder.java:1298) at org.hibernate.cfg.annotations.CollectionBinder.bindStarToManySecondPass(CollectionBinder.java:602) at org.hibernate.cfg.annotations.CollectionBinder$1.secondPass(CollectionBinder.java:543) here is the mapping: @Entity public class Pool { @Id @Column(name = "PK_POOL", unique = true, nullable = false, length = 8) private String id; @OneToMany(fetch = FetchType.LAZY, mappedBy = "id.admin") private Set<PoolAdministrator> adminPools = new HashSet<PoolAdministrator>(0); } @Entity @Table(name = "ADMIN_POOL") public class PoolAdministrator { @EmbeddedId private PoolAdministratorId id; } @Embeddable public class PoolAdministratorId { @ManyToOne(fetch = FetchType.EAGER,optional=false) @JoinColumn(name = "FK_POOL") private Pool pool; } The exception ocures here: property.getPersistentClass().getIdentifier(). Property.getPersistentClass() gives null, where it might give Pool, am I wrong? -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira