使用Struts 2输出时出现JSONexception错误
当我将结果执行到浏览器中时，我收到JSONexception错误，如下所示：
type Exception report message description The server encountered an internal error () that prevented it from fulfilling this request. exception org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.ProductDetails.ISN, no session or session was closed org.apache.struts2.json.JSONWriter.bean(JSONWriter.java:209) org.apache.struts2.json.JSONWriter.process(JSONWriter.java:140) org.apache.struts2.json.JSONWriter.value(JSONWriter.java:216) org.apache.struts2.json.JSONWriter.write(JSONWriter.java:94) org.apache.struts2.json.JSONUtil.serialize(JSONUtil.java:115) org.apache.struts2.json.JSONResult.createJSONString(JSONResult.java:200) org.apache.struts2.json.JSONResult.execute(JSONResult.java:172) com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:361) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:265) com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:163) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:249) org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:148) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:93) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:128) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:104) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:148) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:128) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236) org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52) org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:468) org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77) org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:76) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:366) org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:109) org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:83) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378) org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:97) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378) org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:100) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378) org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:78) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378) org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378) org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:35) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378) org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:187) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378) org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378) org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:378) org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:167) org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237) org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167) 书类：
@Id @GeneratedValue(...) @SequenceGenerator(...) int bookId; @Column(name = "ISN", updatable = false, insertable = false) String ISN; @ManyToOne @JoinColumn(name = "ISN", referencedColumnName = "ISN") BookDetails bD;
我的JSON动作实现很简单：
private List bookIDLists; // getter & setter public String execute() { BooksDAO b = new BooksDAO(); bookIDLists = b.someSearchMethod; return SUCCESS; }
而“getAllBookIDs（）”的hibernate实现如下：
String string = "from Books"; Query query = s.createQuery(string); List list = query.list();
struts.xml文件看起来像：
我测试了方法getAllBookIDs ，我从方法中获得了正确的输出。 但是当我试图通过JSON获取输出并将其执行到浏览器时，我收到错误。
有什么建议可以解决这个例外吗？
问题是在Hibernate会话关闭时发生了对JSON的序列化。
实体可能包含为延迟加载而映射的属性。 默认情况下不加载它们，例如集合和关联。 如果要加载它们，则应在会话打开时执行此操作，例如使用FetchType.EAGER或使用Open Session In View实现。 就像它已经在Full Hibernate插件中完成的那样。
否则，您必须通过@JSON批注控制序列化，并使用带有参数的json结果类型，该参数允许包含和排除JSON结果用于序列化对象的属性。 有关这方面的更多信息，请参阅JSON插件的文档页面。