Caused by: org.hibernate.AnnotationException: Use of @OneToMany or @ManyToMany targeting an unmapped class: org.cnio.appform.entity.User.interviews[org.cnio.appform.entity.Interview]
   at org.hibernate.cfg.annotations.CollectionBinder.bindManyToManySecondPass(CollectionBinder.java:1033)
   at org.hibernate.cfg.annotations.CollectionBinder.bindStarToManySecondPass(CollectionBinder.java:576)
   at org.hibernate.cfg.annotations.CollectionBinder$1.secondPass(CollectionBinder.java:517)
   at org.hibernate.cfg.CollectionSecondPass.doSecondPass(CollectionSecondPass.java:43)
   at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1136)
   at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:316)
   at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1292)
   at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:915)
... 3 more

User owner = (User)session.createCriteria(User.class).
                              add(Restrictions.eq("nickname", nickname)).uniqueResult();
         
         Interview myInt = new Interview (intName, intDesc, owner);
         session.save(myInt);

@Entity
@Table (name="appuser")
@SequenceGenerator(name="UserSeq", sequenceName="appuser_iduser_seq")
//                            allocationSize=1, initialValue=1)
public class User {

@Id @GeneratedValue(strategy=GenerationType.SEQUENCE,generator="UserSeq")
@Column (name="iduser")
   private Integer id;
   
@Column (name="name")
   private String name;
@Column (name="midname")
   private String midname;
@Column (name="lastname")
   private String lastname;
@Column (name="nickname")
   private String nickname;
@Column (name="passwd")
   private String passwd;

// this is to implement the 1-N relathioship between user and interview
@OneToMany (mappedBy="owner",targetEntity=Interview.class)
   private Set<Interview> interviews;
   
// link to the join table to implement the M-N relationship user-role
@OneToMany (mappedBy="user")
   private Set<UserRole> userRoles;


   public User () {
      name = "";
      midname = "";
      lastname = "";
      nickname = "";
      passwd = "";
      userRoles = new HashSet<UserRole> ();
      
      interviews = new HashSet<Interview> ();
   }

// ... various getter an setter methods
}

@Entity
@Table (name="interview")
@SequenceGenerator(name="InterviewSeq",
                            sequenceName="interview_idinterview_seq")
//                            allocationSize=1, initialValue=1)
public class Interview {
@Id @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="InterviewSeq")
@Column (name="idinterview")
   private Integer id;
   
@Column (name="name")
   private String name;
@Column (name="description")
   private String description;

@ManyToOne (targetEntity=User.class)
@JoinColumn(name="iduser")
   private User owner;


   public Interview () {
      name = "";
      description = "";
      owner = new User ();
   }
   
   
/**
* Build an interview with the owner, which is just an user
* @param anUser the owner of this interview
*/   
   public Interview (String name, String description, User anUser) {
// guarantee referential integrity      
      this.owner = anUser;
      
      this.name = name;
      this.description = description;
      
// important to make the relationship inverse      
      owner.getInterviews().add(this);
   }
//... varios getter and setter methods again

}

<mapping class="com.domain.model.State"/>