Java 将新实体添加到持久化集合
我有一对多关联的表:产品*1-n*库存Java 将新实体添加到持久化集合,java,database,hibernate,orm,Java,Database,Hibernate,Orm,我有一对多关联的表:产品*1-n*库存 @Entity public class Product { // Identifier and properties ... @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL) public Set<Inventory> getInventories() { return inventories; } p
@Entity
public class Product {
// Identifier and properties ...
@OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
public Set<Inventory> getInventories() {
return inventories;
}
public void setInventories(Set<Inventory> inventories) {
this.inventories = inventories;
}
public void addInventory(Inventory inventory) {
this.inventories.add(inventory);
inventory.setProduct(this);
}
}
我有以下情况:
HibernateSystemException: a different object with the same identifier value was already associated with the session
异常意味着会话中存在与
@Id
列值相同的对象,并且该对象与当前对象不同
您必须覆盖
Inventory
上的hashCode()
和equals()
(最好使用业务密钥),这样即使对象实例不同,会话也会知道这是同一个实体。如果您根本不添加库存,是否会发生这种情况?否,没有新的库存保存()在库存上给了我同样的解释!我将尝试重写hashcode()和equals()
HibernateSystemException: a different object with the same identifier value was already associated with the session