Jpa 来自不同EntityManagerFactory、PersistentUnit的实体的关系（连接）

我正在开发一个多租户web应用程序

使用的技术堆栈是 SpringWebMVC3.2.x， Spring数据JPA 1.4.3， 日食2.5.1

我需要将所有公共数据（如国家、地区等）保存到单独的单个数据库模式中，将所有租户数据（如用户、历史记录）保存到单个共享数据库模式中（基于鉴别器的模型）

实体模型会是这样的

通用主数据实体-国家

@Entity
@Table (name = "country")
public class Country implements Serializable{

@GeneratedValue(generator = "assigned-by-code")
@GenericGenerator(name = "assigned-by-code", strategy = "assigned")
private String isoCode;

private String name;
}

@Entity
@Multitenant
@Table (name = "user")
public class User {

@Id
@Column (name = "username")
private String userName;

@Column (name = "first_name", nullable = false)
private String firstName;

@Column (name = "last_name", nullable = false)
private String lastName;

@Column (name = "password", nullable = false)
private String password;
...
}

租户实体

@Entity
@Table (name = "country")
public class Country implements Serializable{

@GeneratedValue(generator = "assigned-by-code")
@GenericGenerator(name = "assigned-by-code", strategy = "assigned")
private String isoCode;

private String name;
}

@Entity
@Multitenant
@Table (name = "user")
public class User {

@Id
@Column (name = "username")
private String userName;

@Column (name = "first_name", nullable = false)
private String firstName;

@Column (name = "last_name", nullable = false)
private String lastName;

@Column (name = "password", nullable = false)
private String password;
...
}

因此，我通过为MASTER和TENANT设置两个不同的entityManagerFactory来实现上述隔离，如下所示

针对租户

<bean id="entityManagerFactory"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="raoutingDataSource" />
    <property name="persistenceUnitName" value="tenant" />
    <property name="jpaVendorAdapter">
        <bean
            class="org.springframework.orm.jpa.vendor.EclipseLinkJpaVendorAdapter">
            <property name="database" value="MYSQL" />
            <property name="generateDdl" value="true" />
            <property name="showSql" value="true" />
        </bean>
    </property>
    <property name="jpaProperties">
        <props>
            <prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
            <prop key="hibernate.archive.autodetection">${hibernate.archive.autodetection}</prop>
            <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
            <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
            <prop key="SetBigStringTryClob">true</prop>
        </props>
    </property>
    <property name="packagesToScan">
        <list>
            <value>com.sample.entity</value>
        </list>
    </property>
    <property name="jpaPropertyMap">
        <map>
            <entry key="eclipselink.weaving" value="false" />
        </map>
    </property>
</bean>

但在服务器启动时，会出现如下错误：

Caused by: javax.persistence.PersistenceException: Exception [EclipseLink-28018] (Eclipse Persistence Services - 2.5.1.v20130918-f2b9fc5): org.eclipse.persistence.exceptions.EntityManagerSetupException
Exception Description: Predeployment of PersistenceUnit [tenant] failed.
Internal Exception: Exception [EclipseLink-7250] (Eclipse Persistence Services - 2.5.1.v20130918-f2b9fc5): org.eclipse.persistence.exceptions.ValidationException
Exception Description: [class com.sample.entity.User] uses a non-entity [class com.sample.master.Country] as target entity in the relationship attribute [field country].
    at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.createPredeployFailedPersistenceException(EntityManagerSetupImpl.java:1954) [eclipselink-2.5.1.jar:2.5.1.v20130918-f2b9fc5]

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请按需要操作，因为我不想将主表复制到每个租户的数据源中，因此我需要将其放在单独的位置。

由于租户工厂中不存在国家实体，它无法理解引用。您需要将持久性单元组合成一个，以使引用工作

如果必须将它们分开，EclipseLink支持它所称的复合persistencde单元，允许复合成员之间的关系。这里描述了这一点：

---

而且似乎是你想要的。这使您可以为租户使用复合持久性单元，而读/写操作则应转到下面的不同持久性单元定义。

谢谢Chris，我知道EclipseLink在这种情况下可以帮助我。但是它需要persistence.xml文件才能存在。有没有什么方法可以像上面描述的Spring配置一样配置EclipseLink Composite PesistentUnit及其复合成员？任何一个plz都会对此做出响应@Stackoverflow，请做需要的事情