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我正在尝试将两个不同EntityManagerFactory的实例注入同一个 DAO。我在一个项目中有一个通用的 DAO，我们称之为“项目库”，我有两个不同的项目，项目 A 和项目 B。持久单元在项目库中定义。

我的问题是我希望能够将EntityManagerFactory实例注入 DAO 而不是使用@PersistenceUnit，因为我有两个不同的数据库，一个由项目 A 使用，另一个由项目 B 使用。

我在通用 DAO 中只有基本的 CRUD 操作，但 Spring 给了我以下异常：

Error creating bean with name 'genericHibernateDAO': Injection of persistence dependencies failed; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No unique bean of type [javax.persistence.EntityManagerFactory] is defined: expected single bean but found 2

请在下面找到我的配置：

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="
   http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
   http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd"
    default-autowire="autodetect">
    <context:component-scan base-package="com.entertainment" />


    <!-- Entity Manager -->
    <bean id="abstractEntityManagerFactory"
        class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" abstract="true">
        <property name="jpaVendorAdapter" ref="jpaVendorAdapter" />
        <property name="dataSource" ref="ADataSource" />
    </bean>


    <bean id="AEntityManagerFactory" parent="abstractEntityManagerFactory">
        <property name="persistenceUnitName" value="A" />
    </bean>

    <bean id="BEntityManagerFactory" parent="abstractEntityManagerFactory">
        <property name="persistenceUnitName" value="B" />
    </bean>


    <!-- Datasource -->
    <bean id="ADataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="oracle.jdbc.OracleDriver" />
        <property name="url"
            value="myUrl" />
        <property name="username" value="username" />
        <property name="password" value="password" />
    </bean>

    <bean id="BDataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="oracle.jdbc.OracleDriver" />
        <property name="url"
            value="myUrl" />
        <property name="username" value="username" />
        <property name="password" value="password" />
    </bean>


    <!--  Transaction Manager -->
    <bean id="ATransactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>


    <bean id="BTransactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>

    <!-- Vendor adapter -->
    <bean id="jpaVendorAdapter"
        class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
        <property name="databasePlatform" value="org.hibernate.dialect.Oracle9iDialect" />
        <property name="showSql" value="true" />
        <property name="generateDdl" value="true" />
    </bean>

    <!--  generic DAO -->

    <bean id="genericDAO"
        class="mypackage.GenericHibernateDAO"  abstract="true"/>


</beans>

该文件位于项目库中：

    <persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
     http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
version="2.0">
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
     http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
    version="2.0">
    <persistence-unit name="A" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <properties>
            <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle9Dialect" />
            <property name="hibernate.connection.driver_class" value="oracle.jdbc.OracleDriver" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.connection.username" value="username" />
            <property name="hibernate.connection.password" value="password" />
            <property name="hibernate.connection.url" value="myurl" />
            <property name="hibernate.max_fetch_depth" value="3" />
            <property name="hibernate.archive.autodetection" value="class" />
        </properties>
    </persistence-unit>
    <persistence-unit name="B" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <properties>
            <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle9Dialect" />
            <property name="hibernate.connection.driver_class" value="oracle.jdbc.OracleDriver" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.connection.username" value="username" />
            <property name="hibernate.connection.password" value="password" />
            <property name="hibernate.connection.url" value="myurl" />
            <property name="hibernate.max_fetch_depth" value="3" />
            <property name="hibernate.archive.autodetection" value="class" />
        </properties>
    </persistence-unit>
</persistence>

我一直在努力解决这个问题。我会很感激任何帮助。

提前致谢！

4

2 回答 2

1 
@PersistenceUnit(unitName="A")
EntityManagerFactory entityMgrFactory;

或（这将注入与 persistenceUnit A 相关的 EMFactory）

@Autowired
@Qualified("AEntityManagerFactory")
private EntityManagerFactory AEntityManagerFactory;

或者

@PersistenceContext(unitName="A")
EntityManager em;

没有 unitName 总是期望只有一个 EMFactory 而你有两个，spring 不知道哪个通过。

于 2014-01-31T07:52:51.957 回答
0

您是否尝试过使用配置持久性单元@PersistenceUnit.unitName？

于 2013-10-07T16:41:37.597 回答