spring - 尽管我正在使用@Transactional 注释，但得到“无法初始化代理 - 无会话”

Question

我正在使用 Spring 3.1.1.RELEASE 和 Hibernate 4.1.0.Final。尽管我将相关的方法调用包装在 @Transactional 注释中，但我收到“无法初始化代理 - 无会话”异常。这是我的方法……</p>

@Service("teacherImportService")
public class TeacherImportServiceImpl extends AbstractmyprojectService 
{
    …
    @Transactional
    @Override
    public void saveUserObject(final JsonObject jsonData)  
    {
        …
        final myprojectOrganization myprojectOrg = myprojectOrgDao.findBymyprojectOrgId(myprojectSchoolId);
        final Organization school = myprojectOrg != null ? myprojectOrg.getOrg() : null;
            …
        final Address address = new Address();
        address.setState(school.getState());    // error occurs here

我还需要做什么来保证交易发生？我在我的应用程序上下文中包含了“<tx:annotation-driven />”，我将其包含在下面

<context:component-scan base-package="org.mainco.subco" />
...
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="${test.mysql.dataSource.driverClassName}" />
    <property name="url" value="${test.mysql.dataSource.url}" />
    <property name="username" value="${test.mysql.db.user}" />
    <property name="password" value="${test.mysql.db.password}" />
</bean>

<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="packagesToScan" value="org.mainco.subco" />
    <property name="jpaVendorAdapter">
        <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"/>
    </property>
    <property name="dataSource" ref="dataSource"/>
    <property name="jpaPropertyMap" ref="jpaPropertyMap" />
</bean>

<util:map id="jpaPropertyMap">
    <entry key="hibernate.show_sql" value="true" />
    <entry key="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" /> 
    <entry key="hibernate.cache.region.factory_class" value="org.hibernate.cache.ehcache.EhCacheRegionFactory"/>
    <entry key="hibernate.cache.provider_class" value="org.hibernate.cache.EhCacheProvider"/>
    <entry key="hibernate.cache.use_second_level_cache" value="true" />
    <entry key="hibernate.cache.use_query_cache" value="false" />
    <entry key="hibernate.generate_statistics" value="true" />
</util:map>

<bean id="sharedEntityManager" class="org.springframework.orm.jpa.support.SharedEntityManagerBean">
   <property name="entityManagerFactory" ref="entityManagerFactory"/>
</bean>

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

<tx:annotation-driven />

<jdbc:initialize-database data-source="dataSource">
    <jdbc:script location="classpath:truncate_tables.sql" />
    <jdbc:script location="classpath:db-test-data.sql" />
</jdbc:initialize-database>

这是异常的完整堆栈跟踪...

org.hibernate.LazyInitializationException: could not initialize proxy - no Session
    at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:149)
    at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:195)
    at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:185)
    at org.mainco.subco.organization.domain.Organization_$$_javassist_30.getState(Organization_$$_javassist_30.java)
    at org.mainco.subco.myproject.service.TeacherImportServiceImpl.saveUserObject(TeacherImportServiceImpl.java:101)
    at org.mainco.subco.myproject.service.AbstractmyprojectService.saveUsers(AbstractmyprojectService.java:226)
    at org.mainco.subco.myproject.service.AbstractmyprojectService$$FastClassByCGLIB$$d080e416.invoke(<generated>)
    at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:191)
    at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:618)
    at org.mainco.subco.myproject.service.TeacherImportServiceImpl$$EnhancerByCGLIB$$a06c7e9f.saveUsers(<generated>)
    at org.mainco.subco.myproject.service.TeacherImportServiceTest.testSaveTeachers(TeacherImportServiceTest.java:46)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:231)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:174)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Answer 1

也许您忘记将事务注释添加到AbstractmyprojectService.saveUsers()

请注意，内部调用永远不会被代理，因此流程：

 TeacherImportServiceTest.testSaveTeachers() -> 
 AbstractmyprojectService.saveUsers() -> 
 TeacherImportServiceImpl.saveUserObject()

如果AbstractmyprojectService.saveUsers()根本不是事务性的，则不会是事务性的。

编辑

阅读您的评论后，我看到了三个解决方案：

• 将该方法提取saveUsers()到辅助类。

非常简单，重构您的代码以将 Tx 方法保留在一个类中，并通过组合从另一个类中使用它。

• 在saveUserObject().

例如，注入 txManager 和

public void saveUserObject() {
        DefaultTransactionDefinition def = new DefaultTransactionDefinition();
        def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRES_NEW);
        TransactionStatus status = txManager.getTransaction(def);
        try {
          // the code
        }
        catch (Exception ex) {
          txManager.rollback(status);
          throw ex;
        }
        txManager.commit(status);
    }

• 使用 AspectJ 代替 Spring AOP。（我认为这个选项对于这个问题来说太复杂了。）

使用 AspectJ，您可以用 Aspect 替换 AOP 代理AnnotationTransactionAspect

使用<tx:annotation-driven mode="aspectj"/>并选择一种编织方法（编译或加载时间）。

对于加载时间编织，请参阅http://static.springsource.org/spring/docs/3.0.5.RELEASE/reference/aop.html#aop-aj-ltw

对于使用 maven 进行编译时编织，请参阅Spring / @Transactional with AspectJ is完全忽略

Answer 2

在您的应用程序上下文 XML 中，我没有看到组件扫描配置，它可以让 Spring 管理带注释的立体类型 bean 类 [即，使用@Service、@Repository或@Component注释的类]

只需为以下示例中的任何此类添加包扫描：

<context:component-scan base-package="some.package.where.stereotypedclassesexist"/>

关于 Spring 托管组件的类路径扫描，请参阅此处的 Spring 文档参考。

HTH。

Answer 3

这可能与代理实现模式有关。尝试提取saveUserObject到一个界面：

public class TeacherImportServiceImpl extends AbstractmyprojectService implements SomeInterface {

    @Transactional
    @Override
    public void saveUserObject(final JsonObject jsonData)  {
        ...
    }

}

public interface SomeInterface {
   void saveUserObject(JsonObject jsonData);
}

您也可以尝试使用 CGLIB 进行基于类的代理：

<tx:annotation-driven proxy-target-class="true" />