Hello,

I've got this simple Book-class, whose objects should be stored in a
database:
import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.NamedQuery;

@Entity
@NamedQuery(name = "findAllBooks", query = "SELECT OBJECT(bk) from
Book bk")
public class Book implements Serializable {
    private Long id;
    private String author;
    private String title;
    private boolean available;

    // [...]

    @Id
    @GeneratedValue
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    // [...]
}

I've written the following session bean to handle serialization of the
Book-objects:
import javax.annotation.Resource;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.transaction.UserTransaction;

public class BookBean {
    @PersistenceContext(unitName="books")
    private EntityManager em;
    @Resource
    private UserTransaction utx;
    private Book currentBook = new Book();

    // [...]

    public String submitBook() {
        try {
            utx.begin();
            em.persist(currentBook);
            utx.commit();
        } catch (Exception e) {
            try {
                utx.rollback();
            } catch (Exception e1) {
                e1.printStackTrace();
            }
            e.printStackTrace();
        }
        currentBook = null;
        return "submitBook";
    }
    // [...]
}

The submitBook()-method of the BookBean is called by a .jsp-File from
which the user can create a new Book-object, which is stored in the
currentBook-object. However, when the program reaches the utx.commit()-
statement the following Exception is thrown:
java.lang.IllegalStateException: During synchronization a new object
was found through a relationship that was not marked cascade PERSIST.

       at
oracle.toplink.essentials.internal.ejb.cmp3.base.RepeatableWriteUnitOfWork
$1.iterate(RepeatableWriteUnitOfWork.java:115)

[...]

Does anyone know why I get this strange exception although I haven't
used any relationships at all in my JSF-program?

Thanks for any help.