雙向休眠關系

Question

我有一個使用休眠和以下實體的Web應用程序。 我究竟做錯了什么？

...
@Entity
public class Registration implements BaseEntity {
...
@OneToMany(cascade = {CascadeType.PERSIST}, mappedBy = "registration", fetch = FetchType.EAGER)
private List<OrderedProduct> orderedProducts = new ArrayList<OrderedProduct>();
...
public List<OrderedProduct> getOrderedProducts() {
    return orderedProducts;
}

public void setOrderedProducts(List<OrderedProduct> orderedProducts) {
    this.orderedProducts = orderedProducts;
}
...

---

...
@Entity
public class OrderedProduct implements BaseEntity {
...
@ManyToOne
@JoinColumn(name = "registration_id",nullable = true)
private Registration registration;
...
public Registration getRegistration() {
    return registration;
}
public void setRegistration(Registration registration) {
    this.registration = registration;
}
...

---

當我使用它時，出現以下Tomcat錯誤：

Caused by: org.hibernate.AnnotationException: Illegal use of mappedBy on both sides of the relationship: at.irian.conference.domain.Registration.orderedProducts
    at org.hibernate.cfg.annotations.TableBinder.bindFk(TableBinder.java:193)
    at org.hibernate.cfg.annotations.CollectionBinder.bindCollectionSecondPass(CollectionBinder.java:1325)
    at org.hibernate.cfg.annotations.CollectionBinder.bindManyToManySecondPass(CollectionBinder.java:1164)
    at org.hibernate.cfg.annotations.CollectionBinder.bindStarToManySecondPass(CollectionBinder.java:602)
    at org.hibernate.cfg.annotations.CollectionBinder$1.secondPass(CollectionBinder.java:543)
    at org.hibernate.cfg.CollectionSecondPass.doSecondPass(CollectionSecondPass.java:66)
    at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1163)
    at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:329)
    at org.hibernate.cfg.Configuration.buildMappings(Configuration.java:1148)
    at org.hibernate.ejb.Ejb3Configuration.buildMappings(Ejb3Configuration.java:1226)
    at org.hibernate.ejb.EventListenerConfigurator.configure(EventListenerConfigurator.java:173)
    at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:854)
    at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:425)
    at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:131)
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:221)
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:251)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1288)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1257)
    ... 86 more

Answer 1

此代碼正確，我忘記刪除其他關系

Answer 2

使用List映射集合需要在數據庫中映射一個“序列”列。 您打算用作套裝嗎

Answer 3

我不確定使用注釋的語法。 我們曾經像下面這樣定義這種關系。

Registration.hbm.xml

<bag
    name="orderedProducts"
    inverse="true"
    cascade="appropriate-one"
>
    <key>
        <column name="REGISTRATION_ID" />
    </key>
    <one-to-many 
        class="orderedProducts"
    />
</bag>

OrderedProducts.hbm.xml

<many-to-one
    name="registration"
    class="Registration"
>
    <column name="REGISTRATION_ID"/>
</many-to-one>

Answer 4

嘗試如下所示的注釋。 它將解決您的問題。

@ManyToOne(fetch = FetchType.EAGER)

@JoinColumn(name = "registration_id")

public Registration getRegistration() {
    return registration;
}

public void setRegistration(Registration registration) {
    this.registration = registration;
}

@OneToMany(fetch = FetchType.EAGER, targetEntity = Registration.class, mappedBy = "registration", cascade = { CascadeType.ALL })
@Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN)
@Fetch(FetchMode.SELECT)
@JoinColumn(name = "registration_id")