有一个类似的问题，但是已接受的解决方案不适用（问题是由Spring MVC以某种方式引起的，而在这个类似的问题中并非如此：Spring 3.1 + Hibernate 4.1 JPA, Entity manager factory is registered twice）
要明确我唯一的问题是实体经理工厂的（emf）名称已经注册两次的警告，尽管有警告，我在使用JPA时没有任何问题。
那么，如果spring没有这样做，emf名称是如何第一次加载的，应该/ how_do我停止它？
环境：Glassfish v 3.1.1，Spring 3.1.1，JPA 2.0（Hibernate-entity-manager 4.1.0），Struts2
我收到以下警告：
WARN: HHH000436: Entity manager factory name (empsys) is already registered. If entity manager will be clustered or passivated, specify a unique value for property 'hibernate.ejb.entitymanager_factory_name'
以下是服务器日志的一部分（最后一行是警告，我切断了顶部，但其余部分是连续的）：
INFO: Instantiated an instance of org.hibernate.validator.engine.resolver.JPATraversableResolver.
INFO: HCANN000001: Hibernate Commons Annotations {4.0.1.Final}
INFO: HHH000412: Hibernate Core {4.1.0.Final}
INFO: HHH000206: hibernate.properties not found
INFO: HHH000021: Bytecode provider name : javassist
INFO: HHH000204: Processing PersistenceUnitInfo [
name: empsys
...]
INFO: HHH000130: Instantiating explicit connection provider: org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLInnoDBDialect
INFO: HHH000423: Disabling contextual LOB creation as JDBC driver reported JDBC version [3] less than 4
INFO: HHH000268: Transaction strategy: org.hibernate.engine.transaction.internal.jta.CMTTransactionFactory
INFO: HHH000397: Using ASTQueryTranslatorFactory
INFO: Instantiated an instance of org.hibernate.validator.engine.resolver.JPATraversableResolver.
INFO: Instantiated an instance of org.hibernate.validator.engine.resolver.JPATraversableResolver.
INFO: PWC1412: WebModule[null] ServletContext.log():No Spring WebApplicationInitializer types detected on classpath
INFO: PWC1412: WebModule[null] ServletContext.log():Initializing Spring root WebApplicationContext
INFO: Root WebApplicationContext: initialization started
INFO: Refreshing Root WebApplicationContext: startup date [Sat Sep 01 19:14:15 MDT 2012]; root of context hierarchy
INFO: Loading XML bean definitions from class path resource [applicationContext.xml]
INFO: JSR-250 'javax.annotation.ManagedBean' found and supported for component scanning
INFO: JSR-330 'javax.inject.Named' annotation found and supported for component scanning
INFO: JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
INFO: Bean 'org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter#3170938b' of type [class org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
INFO: Bean 'dataSource' of type [class org.springframework.jndi.JndiObjectFactoryBean] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
INFO: Bean 'dataSource' of type [class com.sun.gjc.spi.jdbc40.DataSource40] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
INFO: Building JPA container EntityManagerFactory for persistence unit 'empsys'
INFO: HHH000204: Processing PersistenceUnitInfo [
name: empsys
...]
INFO: HHH000130: Instantiating explicit connection provider: org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLInnoDBDialect
INFO: HHH000423: Disabling contextual LOB creation as JDBC driver reported JDBC version [3] less than 4
INFO: HHH000268: Transaction strategy: org.hibernate.engine.transaction.internal.jta.CMTTransactionFactory
INFO: HHH000397: Using ASTQueryTranslatorFactory
INFO: Instantiated an instance of org.hibernate.validator.engine.resolver.JPATraversableResolver.
INFO: Instantiated an instance of org.hibernate.validator.engine.resolver.JPATraversableResolver.
WARN: HHH000436: Entity manager factory name (empsys) is already registered. If entity manager will be clustered or passivated, specify a unique value for property 'hibernate.ejb.entitymanager_factory_name'
的web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<welcome-file-list>
<welcome-file>/index.action</welcome-file>
</welcome-file-list>
</web-app>
的applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:jee="http://www.springframework.org/schema/jee"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/jdbc
http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/jee
http://www.springframework.org/schema/jee/spring-jee-3.0.xsd">
<context:annotation-config/>
<context:component-scan base-package="com.kenmcwilliams.employmentsystem" />
<jee:jndi-lookup id="dataSource" jndi-name="jdbc/empsys" />
<bean class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor"/>
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<!-- <property name="persistenceUnitName" value="empsys" /> -->
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"/>
</property>
<property name="dataSource" ref="dataSource"/>
</bean>
<bean id="transactionManager" class="org.springframework.transaction.jta.JtaTransactionManager"/>
<tx:annotation-driven transaction-manager="transactionManager"/>
</beans>
的persistence.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" 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">
<persistence-unit name="empsys" transaction-type="JTA">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<jta-data-source>jdbc/empsys</jta-data-source>
<class>com.quaternion.orm.Something</class>
<properties>
<property name="hibernate.transaction.jta.platform" value="org.hibernate.service.jta.platform.internal.SunOneJtaPlatform"/>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLInnoDBDialect"/>
</properties>
</persistence-unit>
</persistence>
答案 0 :(得分：4)
似乎要求Hibernate为此PU创建两次EMF。 Hibernate跟踪它在注册表中构建的每个EMF。此警告只是告诉您EMF已在同一PU名称下注册。正如警告继续告诉您，如果使用该EMF对应用程序进行集群，则可能会出现问题。否则它只是一个警告，让你知道情况（甚至如何解决它）。
答案 1 :(得分：2)
我相信这个问题可以在这里得到解决：
<context:component-scan base-package="com.kenmcwilliams.employmentsystem" />
您应该过滤掉任何使用@Component注释的JPA的包/类，尤其是创建实体管理器bean的包./。
默认情况下会扫描使用@Component注释的类，至少对于根上下文JPA配置。
我遇到了同样的问题，并通过从组件扫描中过滤JPA配置类来解决它。