ProductItemPk.java

@Embeddable
public class ProductItemPk implements Serializable {

    private Item item;
    private Product product;

    @ManyToOne
    public Item getItem() {
        return item;
    }

    publicvoid setItem(Item item) {
        this.item = item;
    }

    @ManyToOne
    public Product getProduct() {
        return product;
    }

    publicvoid setProduct(Product product) {
        this.product = product;
    }

    publicboolean equals(Object o) {
        if (this== o) returntrue;
        if (o ==null|| getClass() != o.getClass()) returnfalse;

        ProductItemPk that = (ProductItemPk) o;

        if (item !=null?!item.equals(that.item) : that.item !=null) returnfalse;
        if (product !=null?!product.equals(that.product) : that.product !=null)
            returnfalse;

        returntrue;
    }

    publicint hashCode() {
        int result;
        result = (item !=null? item.hashCode() : 0);
        result =31* result + (product !=null? product.hashCode() : 0);
        return result;
    }
}