声明式事务(@Transactional)不适用于Spring中的@Repository

Question

我正在尝试使用Spring,JPA和嵌入式H2数据库进行简单的应用程序.最近我遇到了声明性交易这个奇怪的问题.如果我使用@Repository注释自动装配我的DAO,它们就不会提交.更具体地说,我在flush上获得异常:

javax.persistence.TransactionRequiredException: 
Exception Description: No transaction is currently active

这是我的设置:

persistence.xml中

<persistence-unit name="schedulePU" transaction-type="RESOURCE_LOCAL">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <exclude-unlisted-classes>false</exclude-unlisted-classes>
    <properties>
        <property name="javax.persistence.jdbc.driver" value="org.h2.Driver" />
        <property name="javax.persistence.jdbc.url" value="jdbc:h2:~/scheduleDB" />
        <property name="javax.persistence.jdbc.user" value="sa" />
        <property name="javax.persistence.jdbc.password" value="" />
        <property name="eclipselink.target-database" value="org.eclipse.persistence.platform.database.H2Platform" />
        <property name="eclipselink.ddl-generation" value="drop-and-create-tables" />
        <property name="eclipselink.logging.level" value="FINE"/>
    </properties>
</persistence-unit>

实体

@Entity
@Table(name = "Professors")
public class Professor {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;
    private String name;

    public Professor() { }

    public Professor(String name) {
        this.name = name;
    }
}

DAO

@Repository
public class JpaDao {

    @PersistenceContext
    private EntityManager em;

    @Transactional
    public void addProfessor(Professor professor) {
        em.persist(professor);
        em.flush();
    }
}

database.xml(从root spring context包含)

<beans>
    <context:component-scan base-package="com.spybot.schedule.dao" />

    <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />

    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean">
        <property name="persistenceUnitName" value="schedulePU" />
    </bean>

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

    <tx:annotation-driven transaction-manager="transactionManager" />
</beans>

调节器

@Controller
public class HomeController {

    @Inject
    JpaDao dao;

    @RequestMapping("/add")
    public @ResponseBody String add(String name) {
        Professor p = new Professor(name);
        dao.addProfessor(p);
        return ":)";
    }
}

现在是有趣的部分.如果我从DAO中删除@Repository注释并在database.xml中显式指定它,一切正常.

更新

将另一个<tx:annotation-driven />置于spring servlet配置中可以解决问题,但为什么呢？

Answer 1

可能是因为component-scan在你spring-servlet.xml的扫描中还包括你的DAO类,因此在它的应用程序上下文(而不是"数据库")中为它们创建实例...所以当你的web从web控制器访问这些DAO时,它正在访问它们的非事务版本(除非您添加该tx:annotation-driven标记).

因此,添加该标记实际上是一个糟糕的解决方案,因为它仍然在错误的应用程序上下文中创建DAO实例:更好地base-package为Web层组件创建创建更具体的配置.

我有同样的问题,因为我认为<context:include-filter>在我的spring-servlet.xml照顾只扫描@Controller类...但没有:-(