Hi

I have some trouble understanding a JPA behaviour. Mabye someone could give me a hint. Situation:

Product entity:

@Entity
public class Product implements Serializable {
...
@OneToMany(mappedBy="product", fetch=FetchType.EAGER)
private List<ProductResource> productResources = new ArrayList<ProductResource>();
....
public List<ProductResource> getProductResources() {
    return productResources;
}
public boolean equals(Object obj) {
    if (obj == this) return true;
    if (obj == null) return false;
    if (!(obj instanceof Product)) return false;
    Product p = (Product) obj;
    return p.productId == productId;
}
}

Resource entity:

@Entity
public class Resource implements Serializable {
...
@OneToMany(mappedBy="resource", fetch=FetchType.EAGER)
private List<ProductResource> productResources = new ArrayList<ProductResource>();
...
public void setProductResource(List<ProductResource> productResource) {
    this.productResources = productResource;
}
public List<ProductResource> getProductResources() {
    return productResources;
}
public boolean equals(Object obj) {
    if (obj == this) return true;
    if (obj == null) return false;
    if (!(obj instanceof Resource)) return false;
    Resource r = (Resource) obj;
    return (long)resourceId==(long)r.resourceId;
}   
}

ProductResource Entity: This is a JoinTable (association class) with additional properties (amount). It maps Product and Resources.

@Entity
public class ProductResource implements Serializable {
...
@JoinColumn(nullable=false, updatable=false)
@ManyToOne(fetch=FetchType.EAGER, cascade=CascadeType.PERSIST)
private Product product;

@JoinColumn(nullable=false, updatable=false)
@ManyToOne(fetch=FetchType.EAGER, cascade=CascadeType.PERSIST)
private Resource resource;

private int amount;

public void setProduct(Product product) {
    this.product = product;
    if(!product.getProductResources().contains((this))){
        product.getProductResources().add(this);
    }   
}
public Product getProduct() {
    return product;
}
public void setResource(Resource resource) {
    this.resource = resource;
    if(!resource.getProductResources().contains((this))){
        resource.getProductResources().add(this);
    }       
}
public Resource getResource() {
    return resource;
}
...
public boolean equals(Object obj) {
    if (obj == this) return true;
    if (obj == null) return false;
    if (!(obj instanceof ProductResource)) return false;
    ProductResource pr = (ProductResource) obj;
    return (long)pr.productResourceId == (long)productResourceId;
}   
}

This is the Session Bean (running on glassfish).

@Stateless(mappedName="PersistenceManager")
public class PersistenceManagerBean implements PersistenceManager {

@PersistenceContext(unitName = "local_mysql")
    private EntityManager em;

public Object create(Object entity) {
    em.persist(entity);
    return entity;
}
public void delete(Object entity) {
    em.remove(em.merge(entity));
}
public Object retrieve(Class entityClass, Long id) {
    Object entity = em.find(entityClass, id);
    return entity;
}
public void update(Object entity) {
    em.merge(entity);
}
}

I call the session Bean from a java client:

public class Start {
public static void main(String[] args) throws NamingException {

    PersistenceManager pm = (PersistenceManager) new InitialContext().lookup("java:global/BackITServer/PersistenceManagerBean");

    ProductResource pr = new ProductResource();
    Product p = new Product();
    Resource r = new Resource();

    pr.setProduct(p);
    pr.setResource(r);

    ProductResource pr_stored = (ProductResource) pm.create(pr);

    pm.delete(pr_stored);
    Product p_ret = (Product) pm.retrieve(Product.class, pr_stored.getProduct().getProductId());
// prints out true ????????????????????????????????????
    System.out.println(p_ret.getProductResources().contains(pr_stored));
}
}

So here comes my problem. Why is the ProductResource entity still in the List productResources(see code above). The productResource tuple in the db is gone after the deletion and I do newly retrieve the Product entity. If I understood right every method call of the client happens in a new persistence context, but here i obviously get back the non-refreshed product object!?

Any help is appreciated

Thanks

Marcel