我正在处理一个处理书店的小型maven（多模块）项目。
我在懒惰加载实体集合时遇到问题
用户拥有一系列延迟加载的订单。
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: edu.flst.bookstore.domaine.bo.User.orders, could not initialize proxy - no Session
org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:566)
org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:186)
org.hibernate.collection.internal.AbstractPersistentCollection.readSize(AbstractPersistentCollection.java:137)
org.hibernate.collection.internal.PersistentBag.size(PersistentBag.java:242)
org.dozer.MappingProcessor.prepareDestinationList(MappingProcessor.java:881)
org.dozer.MappingProcessor.addOrUpdateToList(MappingProcessor.java:806)
org.dozer.MappingProcessor.addOrUpdateToList(MappingProcessor.java:894)
org.dozer.MappingProcessor.mapListToList(MappingProcessor.java:730)
org.dozer.MappingProcessor.mapCollection(MappingProcessor.java:580)
org.dozer.MappingProcessor.mapOrRecurseObject(MappingProcessor.java:453)
org.dozer.MappingProcessor.mapFromFieldMap(MappingProcessor.java:361)
org.dozer.MappingProcessor.mapField(MappingProcessor.java:307)
org.dozer.MappingProcessor.map(MappingProcessor.java:267)
org.dozer.MappingProcessor.mapToDestObject(MappingProcessor.java:216)
org.dozer.MappingProcessor.createByCreationDirectiveAndMap(MappingProcessor.java:196)
org.dozer.MappingProcessor.mapGeneral(MappingProcessor.java:170)
org.dozer.MappingProcessor.map(MappingProcessor.java:104)
org.dozer.MappingProcessor.map(MappingProcessor.java:99)
org.dozer.DozerBeanMapper.map(DozerBeanMapper.java:120)
edu.flst.bookstore.transverse.utils.mapper.MapperUtils.map(MapperUtils.java:30)
edu.flst.bookstore.service.impl.UserServiceImpl.rechercher(UserServiceImpl.java:26)
edu.flst.bookstore.presentation.controller.HomeController.index(HomeController.java:20)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:483)
org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:781)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:721)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:943)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:118)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:103)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:154)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:150)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:199)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:110)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:50)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192)
org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160)
org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:344)
org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:261)
我目前正在使用Tomcat，因此我无法添加JTA交易。
我使用Spring的JPA事务管理器来处理事务。
<!-- ============================= -->
<!-- TRANSACTION MANAGER -->
<!-- ============================= -->
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory"/>
</bean>
bean位于我的持久层spring上下文文件中。
我已将@Transactional注释添加到我的抽象服务中（我的所有服务都扩展了此类）
@Service
@Transactional
public abstract class AbstractServiceImpl {
@Autowired protected UserRepository userRepository;
@Autowired protected OrderRepository orderRepository;
@Autowired protected BookRepository bookRepository;
@Autowired protected Mapper mapperService;
}
它实际上并不起作用。我尝试在我的存储库界面中设置注释（我使用的是Spring数据JPA），但它也不起作用。
答案 0 :(得分：0)
如果您检索包含延迟引用的实体并且在您已经离开事务上下文时第一次取消引用此实例，则通常会出现此问题。由于未从数据库中检索到引用，因此无法取消引用。 AFAIK有三个解决这个问题的方法：