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HibernateException in hashCode or in equals
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Solved spring-boothibernatejpahashcodelazy-initialization
M

3

11

I am using spring and hibernate. When fetching without having implemented equals and hashCode, everyting works fine. When I add the two methods and execute the query a Lazyinitializationexception is thrown inside the hashcode.I am assuming that it is happening because hibernate is trying to fill the set of A and its calling hashCode under the hood before the collections are fetched, yet this is only my assumption and would much appreciate if someone gave me a clue. ---------------- In repository ----------------

@Query(value = "select u from User u " +
            "left join fetch u.companies c " +
            "left join fetch c.garages g " +
            "left join fetch g.parkingSpaces pk " +
            "left join fetch u.roles r")
    Set<User> findAllUsers();

---------------- in service ----------------

@Transactional(readOnly = true)
    public Set<User> findAllUsers() {
        return userRepository.findAllUsers();
    }

---------------- in USER ----------------

    @ManyToMany
    @JoinTable(
            name = "users_companies",
            joinColumns = @JoinColumn(name = "users_id", nullable = false, referencedColumnName = "id"),
            inverseJoinColumns = @JoinColumn(name = "companies_id", nullable = false, referencedColumnName = "id")
    )
    private Set<Company> companies;

@Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        User user = (User) o;
        return Objects.equals(email, user.email) &&
                Objects.equals(companies, user.companies) &&
                Objects.equals(roles, user.roles) &&
                Objects.equals(vehicles, user.vehicles);
    }

    @Override
    public int hashCode() {
        return Objects.hash(email, companies, roles, vehicles);
    }

---------------- in COMPANIES ----------------

@Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Company company = (Company) o;
        return Objects.equals(name, company.name) &&
                Objects.equals(garages, company.garages) &&
                Objects.equals(images, company.images);
    }

    @Override
    public int hashCode() {
        return Objects.hash(name, garages, images);
    }

    @OneToMany(mappedBy = "company", orphanRemoval = true)
    private Set<Garage> garages;

Here is the stacktrace:

2020-12-04 17:14:18.500 ERROR 6416 --- [nio-8080-exec-2] o.a.c.c.C.[.[.[.[dispatcherServlet]      : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.orm.jpa.JpaSystemException: collection was evicted; nested exception is org.hibernate.HibernateException: collection was evicted] with root cause

org.hibernate.HibernateException: collection was evicted
    at org.hibernate.event.internal.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:43) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:102) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.internal.SessionImpl.initializeCollection(SessionImpl.java:2164) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.collection.internal.AbstractPersistentCollection$4.doWork(AbstractPersistentCollection.java:589) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:264) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:585) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:149) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.collection.internal.PersistentSet.hashCode(PersistentSet.java:458) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at java.util.Arrays.hashCode(Arrays.java:4685) ~[?:?]
    at java.util.Objects.hash(Objects.java:146) ~[?:?]
    at com.parkeasy.company.Company.hashCode(Company.java:98) ~[classes/:?]
    at java.util.HashMap.hash(HashMap.java:339) ~[?:?]
    at java.util.HashMap.put(HashMap.java:607) ~[?:?]
    at java.util.HashSet.add(HashSet.java:220) ~[?:?]
    at java.util.AbstractCollection.addAll(AbstractCollection.java:352) ~[?:?]
    at org.hibernate.collection.internal.PersistentSet.endRead(PersistentSet.java:355) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollection(CollectionLoadContext.java:239) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollections(CollectionLoadContext.java:224) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.engine.loading.internal.CollectionLoadContext.endLoadingCollections(CollectionLoadContext.java:198) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.loader.Loader.endCollectionLoad(Loader.java:1293) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:1240) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.loader.Loader.processResultSet(Loader.java:1006) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.loader.Loader.doQuery(Loader.java:964) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:350) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.loader.Loader.doList(Loader.java:2887) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.loader.Loader.doList(Loader.java:2869) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2701) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.loader.Loader.list(Loader.java:2696) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:506) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:400) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:219) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1415) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.query.internal.AbstractProducedQuery.doList(AbstractProducedQuery.java:1565) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1533) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.hibernate.query.Query.getResultList(Query.java:165) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
    at org.springframework.data.jpa.repository.query.JpaQueryExecution$CollectionExecution.doExecute(JpaQueryExecution.java:126) ~[spring-data-jpa-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at org.springframework.data.jpa.repository.query.JpaQueryExecution.execute(JpaQueryExecution.java:88) ~[spring-data-jpa-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at org.springframework.data.jpa.repository.query.AbstractJpaQuery.doExecute(AbstractJpaQuery.java:154) ~[spring-data-jpa-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at org.springframework.data.jpa.repository.query.AbstractJpaQuery.execute(AbstractJpaQuery.java:142) ~[spring-data-jpa-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor$QueryMethodInvoker.invoke(QueryExecutorMethodInterceptor.java:195) ~[spring-data-commons-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.doInvoke(QueryExecutorMethodInterceptor.java:152) ~[spring-data-commons-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.invoke(QueryExecutorMethodInterceptor.java:130) ~[spring-data-commons-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:80) ~[spring-data-commons-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:367) ~[spring-tx-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:118) ~[spring-tx-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139) ~[spring-tx-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:149) ~[spring-data-jpa-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:95) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at com.parkeasy.user.$Proxy162.findAllUsers(Unknown Source) ~[?:?]
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?]
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
    at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:344) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:205) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at com.parkeasy.user.$Proxy102.findAllUsers(Unknown Source) ~[?:?]
    at com.parkeasy.user.UserService.findAllUsers(UserService.java:89) ~[classes/:?]
    at com.parkeasy.user.UserService$$FastClassBySpringCGLIB$$302b133c.invoke(<generated>) ~[classes/:?]
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:771) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:367) ~[spring-tx-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:118) ~[spring-tx-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:691) ~[spring-aop-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at com.parkeasy.user.UserService$$EnhancerBySpringCGLIB$$e8d727f.findAllUsers(<generated>) ~[classes/:?]
    at com.parkeasy.user.UserController.details(UserController.java:40) ~[classes/:?]
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?]
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
    at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) ~[spring-webmvc-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:878) ~[spring-webmvc-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:792) ~[spring-webmvc-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:626) ~[tomcat-embed-core-9.0.38.jar:4.0.FR]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) ~[tomcat-embed-core-9.0.38.jar:4.0.FR]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.38.jar:9.0.38]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.springframework.web.filter.AbstractRequestLoggingFilter.doFilterInternal(AbstractRequestLoggingFilter.java:289) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:320) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:126) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:90) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:118) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:158) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilterInternal(BasicAuthenticationFilter.java:204) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:116) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.csrf.CsrfFilter.doFilterInternal(CsrfFilter.java:117) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:92) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:77) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178) ~[spring-security-web-5.3.4.RELEASE.jar:5.3.4.RELEASE]
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:358) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:271) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) [tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) [tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143) [tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) [tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374) [tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590) [tomcat-embed-core-9.0.38.jar:9.0.38]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.38.jar:9.0.38]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.38.jar:9.0.38]
    at java.lang.Thread.run(Thread.java:834) [?:?]
Motion answered 29/11, 2020 at 9:35 Comment(2)
Try to prefetch your data in a smaller transaction or extend the boundaries of transaction. Later is not recommended and should tune it before putting in production environment. – Unkindly
Can you post the exception stack trace? – Evacuate
W
14

That's an interesting issue (bug) you ran into. Note that it's not a LazyInitializationException:

org.hibernate.HibernateException: collection was evicted

It happens when you load 2+ collections in depth due to join fetch and you use HashSet/hashCode. Hibernate knows it had to fetch the inner collection of Company#garages but at the moment when Company#hashCode is invoked (which happens in Hibernate internal code due to HashSet) - it hasn't done this yet. So it gets confused because the collection has been requested and it should've been loaded - but it's not there. This could be called a bug though I wouldn't create a ticket for it - I'd rather change the code.

Iterating over other entities in equals/hashCode is inefficient and will result it more bugs. These methods should use immutable fields, even using id may cause issues in case it's assigned during persistence (identity and sequence strategies).

You can skip equals/hashCode methods in Entities all together since ORM will ensure there's only 1 instance loaded via Session/EntityManager. This means that the references will always be the same and thus default hashCode will work just fine.

equals/hashCode are important for Value Objects (they aren't stored in DB), but for entities it's safer to rid of them.

Wizardly answered 7/12, 2020 at 6:15 Comment(2)
To be fair to Hibernate folks, this is not a bug, this is simply undefined behaviour. As in 'we don't know what's gonna happen when you use the unsupported functionality of nested JOIN FETCHes, but things are pretty likely to break' – Cavy
@crizzis, the link that you provided in your answer doesn't reference any part of the spec that says it's not allowed ¯\_(ツ)_/¯ But regardless of that - Hibernate (not JPA) does support nested JOIN FETCH, they even have examples in the docs: docs.jboss.org/hibernate/core/3.3/reference/en/html/… Though they do mention there could be issues with some types of collections, but those should be related to the collections' content. That being said - I don't think Hibernate guys should fix this, it seems like a complicated problem and no one will benefit. – Wizardly
T
3

To avoid a LazyInitializationException inside your hashCode() or equals() method, just do not call any collections within your object. Read below why this implementation has a constant hash code and an equals method which relies solely on the primary key.

@Override
public boolean equals(Object o) {
    if (this == o) return true;
    if (!(o instanceof User)) return false;
    User user = (User) o;
    return id != null && id.equals(user.getId());
}

@Override
public int hashCode() {
    return 24;
}

The previous example is for the class User and assumes that the primary key is called id and is implemented as a class (not a primitive datatype) to get proper null values. This blog article describes very well why this strange implementation can and should be used.

Justification

equals() and hashCode() have to return equal values for the same object. The entity which is compared must be equal to itself in all possible JPA stages. An attribute which is unique to each entity of a class and consistent (because it cannot be changed) is the database key.

The only issue with it exists in the transient state which is before the entity is persisted. However, before persisting an object, objects can only be considered equal if there reference is equal. If the objects are persisted, obviously each primary key refers to exactly one entity per class/table.

With this argumentation, the primary key forms an appropriate business key for the equals() method. However, when the primary key is used in the function hashCode() and an object is stored for example in a Set before it is persisted, the hash code would change when persisting the object and the Set would not work anymore. The way to keep the result of hashCode() true when equals() returns true, it cannot rely on the primary key.

According to the argumentation below, this implementation defeats the performance benefits of structures like HashMap and HashSet. "However, for performance reasons, you should always limit the number of entities that are stored in a collection." The performance penalty on side of the database is way higher than using only a single bucket.

Tumefaction answered 7/12, 2020 at 4:54 Comment(6)
For efficiency, it is better anyway to have a fixed hash code - your suggested implementation is the least efficient implementation possible. This turns hash-based collections (O(1)) into lists (O(n)). Also - OP doesn't have LazyInitializationException. – Wizardly
I added an explanation why an implementation like this is okay. – Tumefaction
This implementation is not okay. If you don't want to implement hashCode correctly - then why bother using Hash-based collections? Use Lists, they are safer. I've posted a comment to the article you're referring, but it's awaiting moderation. In the majority of cases you should simply not implement equals/hashCode for entities. ValueObjects are those who need these methods - not entities. – Wizardly
This argumentation makes sense. However, the basic implementation of the hashCode() function just generates an int for the memory address. Would a database entity therefore not need an overwritten hash function (and therefore also an overwritten `equals() function) to comply with the JPA principles? – Tumefaction
Yep, neither equals() nor hashCode() are necessary to work with JPA. – Wizardly
BTW, default hashCode() is not necessarily a memory address, seems like most of the time it's just a random number generated when object was created, at least in OpenJDK: srvaroa.github.io/jvm/java/openjdk/biased-locking/2017/01/30/… – Wizardly
C
1

First of all, the left join B b left join C c left join D d part of your query doesn't really do anything except for hindering the query performance with redundant JOINs. You might have wanted JOIN FETCH instead. However, please read this question first before putting FETCH everywhere.

Second of all, if your hashCode (or any other method, for that matter) tries to access a lazily fetched collection outside of an open persistence context, then yes, you'll be getting LazyInitializationExceptions. The solution is, well, to not make your methods do that.

EDIT Are you using 2nd level cache, by any chance? I cannot say for sure that it will help, because as the answer I linked to points out, nested FETCH JOINs are not supported, but try adding cascade = DETACH to all the eagerly fetched associations

Cavy answered 29/11, 2020 at 10:49 Comment(4)
I had forgotten to add the fetch, when i was writing the query here, but in the project, it has fetch – Motion
tries to access a lazily fetched collection outside of an open persistence context - which isn't the case, have a closer to look at the stack trace. – Wizardly
@StanislavBashkyrtsev The question details have changed since this answer was posted – Cavy
I understand that. – Wizardly

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