java - Add new Entity to persisted Collection -

I've got the related table in multiple-to-many associations: Product * 1 - n * Inventory

< Previous> @Entity Public Category Products {// Identifier and Properties ... @OnTomy (fetch = fetchtype.EAGER, cascade = CascadeType.ALL) Public set & lt; Inventory & gt; GetInventories () {Return List; } Public Zero Set Inventory (set & lt; Inventory & gt; inventories) {This list = inventories; } Public Zero addInventory (Inventory Inventory) {this.inventories.add (list); Inventory.setProduct (this); }}

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  @Entity public category list {// identifier and property ... private product product; @ManyToOne (cascade = cascade type.all, alternative = false) public product getProduct () {return product; } Public Zero Set Product (Product Product) {this.product = Product; }}  

I have followed the seatement:

1. I continue a product with a blank inventory set
2. I Loading the product
4. I try to update / merge the product

By doing this, I get the exception:

  HibernateSystemException: A different object with the same identifier value was already associated with the session  

means of exception Land that exists in the session contains an object with the same value of @ id column, which is not the same thing as the current object.

You have to overwrite hashode () and equals () on list (preferably using a business key By which the session will know that the same entity, even if the object example is different.