persisted data changed after rest service return

Question

I have a REST service that use a stateless bean to perform an algorithm by using other beans. All those beans made changes to the fields of my data, including a ManyToOne field. At the end of the algorithm, just before the “return” of my rest service, my data is in the correct state, and the ManyToOne field in question has been changed. But just after the return of the rest service, an update seems to happen on that field, and change it back to its previous state. But the other fields are still in the correct state.

What could possibly change my data after the “return” of my rest service ?

The project work with hibernate and JTA transactions in a wildfly environment.

The data looks like below :

public class Data extends JpaDecorator {
    @Column(length=1024)
    @Override
    public String getCommentaire() {
        return getImpl().getCommentaire();
    }

    @Column(length=1024)
    @Override
    public void setCommentaire(String value) {
        getImpl().setCommentaire(value);
    }
}

@MappedSuperclass
public class JpaDecorator<T> {

    private WorkspaceJpa workspaceJpa;

    private T impl;

    @Transient
    public T getImpl() {
        return impl;
    }

    @ManyToOne
    @JoinColumn(name = "wid", referencedColumnName = "oid")
    public WorkspaceJpa getJpaWid() {
        return this.workspaceJpa;
    }

    public void setJpaWid(WorkspaceJpa value) {
        this.workspaceJpa = value;

        Workspace wks = ((this.workspaceJpa != null) ? this.workspaceJpa.getImpl() : null);
        getImpl().setWid(wks);
    }

}

EDIT : I finally solved the problem. It came from an unclosed transaction used to collect the data at the beginning of the algorithm. That transaction stayed alive until the return of the rest service, and then was forced to end and flush the state of its data, which was obsolete.