未能延迟初始化角色集合：br.com.coderi.adi.model.Usuario.papeis，无法初始化代理 - 无会话
failed to lazily initialize a collection of role: br.com.coderi.adi.model.Usuario.papeis, could not initialize proxy - no Session
我正在与 Java 1.8 合作处理实体 @OneToMany 和 @ManyToOne 与 [= 之间的关系62=]-MVC 和 Spring-Data-JPA，但出现以下错误：
GRAVE: Servlet.service() for servlet [appServlet] in context with path [/adi] threw exception [Request processing failed; nested exception is org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: br.com.coderi.adi.model.Usuario.papeis, could not initialize proxy - no Session] with root cause
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: br.com.coderi.adi.model.Usuario.papeis, could not initialize proxy - no Session
我可以添加一个用户 (Usuario) 和他们的角色 (Papeis)，但是执行查询总是会出现上述错误。
实体Usuario：
@Entity
public class Usuario {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
@NotEmpty
private String nome;
@NotEmpty
private String email;
@NotEmpty
@Size(min = 2, max = 25)
@Column(unique = true)
private String login;
@NotEmpty
@Size(min = 6)
private String senha;
@Transient
private String confirmSenha;
private Boolean status;
@OneToMany(mappedBy = "usuario")
private List<Papel> papeis;
<!-- Getters/Setters... -->
}
实体纸币：
@Entity
public class Papel {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
@NotEmpty
private String papel;
@ManyToOne
private Usuario usuario;
<!-- Getters/Setters... -->
}
一个用户（Usuario）可以有多个角色（Papel），各个角色必须属于一个用户。这是正确的做法吗？
服务：
@Service
public class PapelService {
@Autowired
private PapelReposiroty papelRepository;
public Papel getPapel(Integer id) {
return papelRepository.findOne(id);
}
public Papel adicionar(Papel papel) {
return papelRepository.save(papel);
}
public List<Papel> listarPapeisPorUsuario(Usuario usuario) {
return papelRepository.findPapelByUsuario(usuario);
}
}
存储库：
@Repository
public interface PapelReposiroty extends CrudRepository<Papel, Integer> {
public List<Papel> findPapelByUsuario(Usuario usuario);
}
在我的 Controller 中添加 user/roles 后，当我执行 papelService.getPapel(1) 时，我得到了这个引用错误。感谢您的帮助！
Ps: The error occurs only when using the methods of relationships.
数据库:
所有堆栈跟踪：
GRAVE: Servlet.service() for servlet [appServlet] in context with path [/adi] threw exception [Request processing failed; nested exception is org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: br.com.coderi.adi.model.Usuario.papeis, could not initialize proxy - no Session] with root cause
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: br.com.coderi.adi.model.Usuario.papeis, could not initialize proxy - no Session
at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:579)
at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:203)
at org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:558)
at org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:131)
at org.hibernate.collection.internal.PersistentBag.toString(PersistentBag.java:509)
at java.lang.String.valueOf(String.java:2982)
at java.lang.StringBuilder.append(StringBuilder.java:131)
at br.com.coderi.adi.model.Usuario.toString(Usuario.java:113)
at java.lang.String.valueOf(String.java:2982)
at java.lang.StringBuilder.append(StringBuilder.java:131)
at br.com.coderi.adi.model.Papel.toString(Papel.java:66)
at java.lang.String.valueOf(String.java:2982)
at java.io.PrintStream.println(PrintStream.java:821)
at org.apache.tomcat.util.log.SystemLogHandler.println(SystemLogHandler.java:267)
at br.com.coderi.adi.controller.PapelController.adicionarForm(PapelController.java:39)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:317)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:127)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:91)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:115)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:112)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:169)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilterInternal(BasicAuthenticationFilter.java:158)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:206)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:121)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.csrf.CsrfFilter.doFilterInternal(CsrfFilter.java:100)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:66)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:106)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:214)
at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:177)
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1526)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1482)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
How to Enable Lazy Loading in Hibernate
在继续前进之前，回顾一下默认行为很重要
在使用休眠映射与注释的情况下延迟加载。
默认行为是加载“属性 值”并加载
'collection懒惰'。与你可能记得的相反，如果你有
之前使用过纯 Hibernate 2（映射文件），其中所有引用
(包括 collections) 默认情况下是急切加载的。还要注意的是
@OneToMany 和@ManyToMany 关联默认为 LAZY 加载；
@OneToOne 和@ManyToOne 默认为 EAGER 加载。这是
重要的是要记住以避免将来出现任何陷阱。
要显式启用延迟加载，您必须使用“fetch =
FetchType.LAZY" 在您想要延迟加载的关联上
正在使用休眠注释。
示例用法如下所示：
@OneToMany(mappedBy = "category", fetch = FetchType.LAZY) 私有
集产品；另一个属性平行于
"FetchType.LAZY" 是 "FetchType.EAGER" 与 LAZY 正好相反
即当所有者实体是
第一次获取。
延迟加载在 Hibernate 中的工作原理
Hibernate 可以在您的应用程序上应用延迟加载行为的最简单方法
实体和协会是通过提供代理实现
他们。 Hibernate通过代理来拦截对实体的调用
因为它源自实体的 class。要求的地方
信息丢失，之前会从数据库中加载
控制权移交给 parent 实体的实施。
请注意，当关联表示为 collection
class，然后是包装器（本质上是 collection 的代理，而不是
比它包含的实体）被创建并替换为
原来collection。当您访问此 collection 代理时
您在返回的代理 collection 中得到的不是代理实体；
相反，它们是实际的实体。你不需要施加太大压力
理解这个概念，因为在运行时它并不重要。
您使用@OnetoMany 关系。
知道就解决了
您使用 fetch.
您的实体
@Entity
public class Usuario {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
@NotEmpty
private String nome;
@NotEmpty
private String email;
@NotEmpty
@Size(min = 2, max = 25)
@Column(unique = true)
private String login;
@NotEmpty
@Size(min = 6)
private String senha;
@Transient
private String confirmSenha;
private Boolean status;
@OneToMany(mappedBy = "usuario")
private List<Papel> papeis;
<!-- Getters/Setters... -->
}
你搜索"jpa fetch lazy"。
但。获取，许多搜索关系。 :)
IT 无法正常工作的原因是您的会话即将关闭。这可以在交易结束后自动发生。然后实体进入"detached"状态。当发生这种情况时，所有对未初始化的惰性代理的访问都将导致此 exception.Of 课程，最简单的解决方法是将其标记为 EAGER。如果你想让 IT 保持懒惰为了修复 IT，你需要在 IT 分离之前在事务中初始化这个集合。如果您不将服务包装在 transactin 中，另一种方法是使用带有 fetch 子句的 HQL 查询来确保集合已初始化。如果您按照这些步骤操作，您可以保留 LAZY FetchType
我正在与 Java 1.8 合作处理实体 @OneToMany 和 @ManyToOne 与 [= 之间的关系62=]-MVC 和 Spring-Data-JPA，但出现以下错误：
GRAVE: Servlet.service() for servlet [appServlet] in context with path [/adi] threw exception [Request processing failed; nested exception is org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: br.com.coderi.adi.model.Usuario.papeis, could not initialize proxy - no Session] with root cause
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: br.com.coderi.adi.model.Usuario.papeis, could not initialize proxy - no Session
我可以添加一个用户 (Usuario) 和他们的角色 (Papeis)，但是执行查询总是会出现上述错误。
实体Usuario：
@Entity
public class Usuario {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
@NotEmpty
private String nome;
@NotEmpty
private String email;
@NotEmpty
@Size(min = 2, max = 25)
@Column(unique = true)
private String login;
@NotEmpty
@Size(min = 6)
private String senha;
@Transient
private String confirmSenha;
private Boolean status;
@OneToMany(mappedBy = "usuario")
private List<Papel> papeis;
<!-- Getters/Setters... -->
}
实体纸币：
@Entity
public class Papel {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
@NotEmpty
private String papel;
@ManyToOne
private Usuario usuario;
<!-- Getters/Setters... -->
}
一个用户（Usuario）可以有多个角色（Papel），各个角色必须属于一个用户。这是正确的做法吗？
服务：
@Service
public class PapelService {
@Autowired
private PapelReposiroty papelRepository;
public Papel getPapel(Integer id) {
return papelRepository.findOne(id);
}
public Papel adicionar(Papel papel) {
return papelRepository.save(papel);
}
public List<Papel> listarPapeisPorUsuario(Usuario usuario) {
return papelRepository.findPapelByUsuario(usuario);
}
}
存储库：
@Repository
public interface PapelReposiroty extends CrudRepository<Papel, Integer> {
public List<Papel> findPapelByUsuario(Usuario usuario);
}
在我的 Controller 中添加 user/roles 后，当我执行 papelService.getPapel(1) 时，我得到了这个引用错误。感谢您的帮助！
Ps: The error occurs only when using the methods of relationships.
数据库:
所有堆栈跟踪：
GRAVE: Servlet.service() for servlet [appServlet] in context with path [/adi] threw exception [Request processing failed; nested exception is org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: br.com.coderi.adi.model.Usuario.papeis, could not initialize proxy - no Session] with root cause
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: br.com.coderi.adi.model.Usuario.papeis, could not initialize proxy - no Session
at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:579)
at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:203)
at org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:558)
at org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:131)
at org.hibernate.collection.internal.PersistentBag.toString(PersistentBag.java:509)
at java.lang.String.valueOf(String.java:2982)
at java.lang.StringBuilder.append(StringBuilder.java:131)
at br.com.coderi.adi.model.Usuario.toString(Usuario.java:113)
at java.lang.String.valueOf(String.java:2982)
at java.lang.StringBuilder.append(StringBuilder.java:131)
at br.com.coderi.adi.model.Papel.toString(Papel.java:66)
at java.lang.String.valueOf(String.java:2982)
at java.io.PrintStream.println(PrintStream.java:821)
at org.apache.tomcat.util.log.SystemLogHandler.println(SystemLogHandler.java:267)
at br.com.coderi.adi.controller.PapelController.adicionarForm(PapelController.java:39)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:317)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:127)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:91)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:115)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:112)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:169)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilterInternal(BasicAuthenticationFilter.java:158)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:206)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:121)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.csrf.CsrfFilter.doFilterInternal(CsrfFilter.java:100)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:66)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:106)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:214)
at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:177)
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1526)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1482)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
How to Enable Lazy Loading in Hibernate
在继续前进之前，回顾一下默认行为很重要 在使用休眠映射与注释的情况下延迟加载。
默认行为是加载“属性 值”并加载 'collection懒惰'。与你可能记得的相反，如果你有 之前使用过纯 Hibernate 2（映射文件），其中所有引用 (包括 collections) 默认情况下是急切加载的。还要注意的是 @OneToMany 和@ManyToMany 关联默认为 LAZY 加载； @OneToOne 和@ManyToOne 默认为 EAGER 加载。这是 重要的是要记住以避免将来出现任何陷阱。
要显式启用延迟加载，您必须使用“fetch = FetchType.LAZY" 在您想要延迟加载的关联上 正在使用休眠注释。
示例用法如下所示：
@OneToMany(mappedBy = "category", fetch = FetchType.LAZY) 私有 集产品；另一个属性平行于 "FetchType.LAZY" 是 "FetchType.EAGER" 与 LAZY 正好相反 即当所有者实体是 第一次获取。
延迟加载在 Hibernate 中的工作原理
Hibernate 可以在您的应用程序上应用延迟加载行为的最简单方法 实体和协会是通过提供代理实现 他们。 Hibernate通过代理来拦截对实体的调用 因为它源自实体的 class。要求的地方 信息丢失，之前会从数据库中加载 控制权移交给 parent 实体的实施。
请注意，当关联表示为 collection class，然后是包装器（本质上是 collection 的代理，而不是 比它包含的实体）被创建并替换为 原来collection。当您访问此 collection 代理时 您在返回的代理 collection 中得到的不是代理实体； 相反，它们是实际的实体。你不需要施加太大压力 理解这个概念，因为在运行时它并不重要。
您使用@OnetoMany 关系。
知道就解决了
您使用 fetch.
您的实体
@Entity
public class Usuario {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
@NotEmpty
private String nome;
@NotEmpty
private String email;
@NotEmpty
@Size(min = 2, max = 25)
@Column(unique = true)
private String login;
@NotEmpty
@Size(min = 6)
private String senha;
@Transient
private String confirmSenha;
private Boolean status;
@OneToMany(mappedBy = "usuario")
private List<Papel> papeis;
<!-- Getters/Setters... -->
}
你搜索"jpa fetch lazy"。 但。获取，许多搜索关系。 :)
IT 无法正常工作的原因是您的会话即将关闭。这可以在交易结束后自动发生。然后实体进入"detached"状态。当发生这种情况时，所有对未初始化的惰性代理的访问都将导致此 exception.Of 课程，最简单的解决方法是将其标记为 EAGER。如果你想让 IT 保持懒惰为了修复 IT，你需要在 IT 分离之前在事务中初始化这个集合。如果您不将服务包装在 transactin 中，另一种方法是使用带有 fetch 子句的 HQL 查询来确保集合已初始化。如果您按照这些步骤操作，您可以保留 LAZY FetchType