I have a many-to-many relationship between Stores and Products, represented by the following code (mostly based in this answer):
@Entity
@Table(name = "Store")
public class Store {
private long idStore;
// ...
private Collection<StoreHasProduct> storeHasProducts = new ArrayList<>();
@OneToMany(mappedBy = "store", cascade = {CascadeType.MERGE, CascadeType.PERSIST}, fetch = FetchType.EAGER)
public Collection<StoreHasProduct> getStoreHasProducts() {
return storeHasProducts;
}
public void setStoreHasProducts(Collection<StoreHasProduct> storeHasProducts) {
this.storeHasProducts = storeHasProducts;
}
}
@Entity
@Table(name="Product")
public class Product {
private long idProduct;
// ...
private Collection<StoreHasProduct> storeHasProducts = new ArrayList<>();
@OneToMany(mappedBy = "product", fetch = FetchType.LAZY)
public Collection<StoreHasProduct> getStoreHasProducts() {
return storeHasProducts;
}
public void setStoreHasProducts(Collection<StoreHasProduct> storeHasProducts) {
this.storeHasProducts = storeHasProducts;
}
}
@Entity
@Table(name = "Store_has_Product")
@IdClass(StoreHasProductPK.class)
public class StoreHasProduct implements java.io.Serializable {
@Id
@ManyToOne
@JoinColumn(name = "Store_idStore",updatable = true)
private Store store;
@Id
@ManyToOne
@JoinColumn(name = "Product_idProduct", updatable = true)
private Product product;
}
public class StoreHasProductPK implements java.io.Serializable {
private Long store;
private Long product;
}
All basic insertion are working fine. However, when I try to add new Products to a existing Store I'm having a PersistentObjectException: detached entity passed to persist exception. This happens, for example, in the following test:
@Test
public void testAssignProductToAnExistingStore() throws Exception {
//Create a store
Store store = getStore();
//Create and save a product
Product product = getProduct();
StoreHasProduct storeHasProduct = getStoreHasProduct(store, product);
store.getStoreHasProducts().add(storeHasProduct);
storeRepository.save(store);
//Create and save a second product
Product productTwo = getProduct();
Store s = storeRepository.findOne(store.getIdStore());
product.getStoreHasProducts().add(getStoreHasProduct(s, productTwo));
productRepository.save(product);
// s.getStoreHasProducts().add(getStoreHasProduct(s, productTwo));
// storeRepository.save(s);
}
If I try to persist the product, I get detached entity passed to persist: Product. If instead I try to persist the store (commented code) I get the same exception but for store.
What should I do? I'm trying to use the CASCADE.DETACH, but I'm not sure if this is the appropriate path to follow.
Thanks
