working code with no error:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::http://localhost:8084/ttmaven/box/create/board/3/vertical/MyBoxTitle{"id":33,"parentBoard":null,"parentBox":null,"childBoxList":[],"taskList":[],"company":null,"boxPrivilegesList":[],"type":null,"title":"MyBoxTitle","description":null,"isFirstLevelBox":false,"userList":[]}controller (new with entity bean instead of real entity)=======//ajax @RequestMapping (value = "/box/create/{parent}/{parentId}/{boxType}/{boxTitle}", method=RequestMethod.GET) public @ResponseBody web.entityBeans.Boxes createBox(ModelMap model, @PathVariable(value="parent") String parent, @PathVariable(value="parentId") String parentId, @PathVariable(value="boxType") String boxType, @PathVariable(value="boxTitle") String boxTitle ){ //queue //get user id from session (save id in session first) //verify for privs of user if he can create box or not. //create box in the parent board / box Boxes box = new Boxes(); box.setTitle(boxTitle); box.setType(boxType); if(parent.equals("board")){ box.setIsFirstLevelBox(true); //do this in service rather here. / that is set parent of box. Boards board = new Boards(); board = (Boards)( boardService.getBoardById(Long.valueOf(parentId)) ).getObject(); boxService.setParent(box, board); }else if(parent.equals("box")){ Boxes parentBox = new Boxes(); parentBox = (Boxes)( boxService.getBoxById(Long.valueOf(parentId)) ).getObject(); boxService.setParent(box, parentBox); } Boxes savedBox = (Boxes)boxService.save(box).getObject(); System.out.println("box saved title was "+ savedBox.getTitle()); web.entityBeans.Boxes b = new web.entityBeans.Boxes(); b.setTitle(savedBox.getTitle()); b.setId(savedBox.getId()); return b; }::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::error==========HTTP Status 500 - Could not write JSON: failed to lazily initialize a collection of role: web.entity.Boards.childBoxList, could not initialize proxy - no Session (through reference chain: web.entity.Boxes["parentBoard"]->web.entity.Boards["childBoxList"]); nested exception is org.codehaus.jackson.map.JsonMappingException: failed to lazily initialize a collection of role: web.entity.Boards.childBoxList, could not initialize proxy - no Session (through reference chain: web.entity.Boxes["parentBoard"]->web.entity.Boards["childBoxList"])type Exception reportmessage Could not write JSON: failed to lazily initialize a collection of role: web.entity.Boards.childBoxList, could not initialize proxy - no Session (through reference chain: web.entity.Boxes["parentBoard"]->web.entity.Boards["childBoxList"]); nested exception is org.codehaus.jackson.map.JsonMappingException: failed to lazily initialize a collection of role: web.entity.Boards.childBoxList, could not initialize proxy - no Session (through reference chain: web.entity.Boxes["parentBoard"]->web.entity.Boards["childBoxList"])description The server encountered an internal error that prevented it from fulfilling this request.exceptionorg.springframework.http.converter.HttpMessageNotWritableException: Could not write JSON: failed to lazily initialize a collection of role: web.entity.Boards.childBoxList, could not initialize proxy - no Session (through reference chain: web.entity.Boxes["parentBoard"]->web.entity.Boards["childBoxList"]); nested exception is org.codehaus.jackson.map.JsonMappingException: failed to lazily initialize a collection of role: web.entity.Boards.childBoxList, could not initialize proxy - no Session (through reference chain: web.entity.Boxes["parentBoard"]->web.entity.Boards["childBoxList"]) org.springframework.http.converter.json.MappingJacksonHttpMessageConverter.writeInternal(MappingJacksonHttpMessageConverter.java:194) org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:179) org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:148) org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:90) org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:189) org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:69) org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:122) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686) org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80) org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925) org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856) org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936) org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:827) javax.servlet.http.HttpServlet.service(HttpServlet.java:621) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812) javax.servlet.http.HttpServlet.service(HttpServlet.java:722) 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$VirtualFilterChain.doFilter(FilterChainProxy.java:342) org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54) org.springframework.security.web.FilterChainProxy$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:183) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105) org.springframework.security.web.FilterChainProxy$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:346) org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:259)root causeorg.codehaus.jackson.map.JsonMappingException: failed to lazily initialize a collection of role: web.entity.Boards.childBoxList, could not initialize proxy - no Session (through reference chain: web.entity.Boxes["parentBoard"]->web.entity.Boards["childBoxList"]) org.codehaus.jackson.map.JsonMappingException.wrapWithPath(JsonMappingException.java:218) org.codehaus.jackson.map.JsonMappingException.wrapWithPath(JsonMappingException.java:183) org.codehaus.jackson.map.ser.std.SerializerBase.wrapAndThrow(SerializerBase.java:140) org.codehaus.jackson.map.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:158) org.codehaus.jackson.map.ser.BeanSerializer.serialize(BeanSerializer.java:112) org.codehaus.jackson.map.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:446) org.codehaus.jackson.map.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:150) org.codehaus.jackson.map.ser.BeanSerializer.serialize(BeanSerializer.java:112) org.codehaus.jackson.map.ser.StdSerializerProvider._serializeValue(StdSerializerProvider.java:610) org.codehaus.jackson.map.ser.StdSerializerProvider.serializeValue(StdSerializerProvider.java:256) org.codehaus.jackson.map.ObjectMapper.writeValue(ObjectMapper.java:1613) org.springframework.http.converter.json.MappingJacksonHttpMessageConverter.writeInternal(MappingJacksonHttpMessageConverter.java:191) org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:179) org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:148) org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:90) org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:189) org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:69) org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:122) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686) org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80) org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925) org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856) org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936) org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:827) javax.servlet.http.HttpServlet.service(HttpServlet.java:621) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812) javax.servlet.http.HttpServlet.service(HttpServlet.java:722) 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:54) 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$VirtualFilterChain.doFilter(FilterChainProxy.java:342) org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:183) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105) 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:346) org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:259)root causeorg.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: web.entity.Boards.childBoxList, 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.initialize(AbstractPersistentCollection.java:545) org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:124) org.hibernate.collection.internal.PersistentBag.iterator(PersistentBag.java:266) org.codehaus.jackson.map.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:45) org.codehaus.jackson.map.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:23) org.codehaus.jackson.map.ser.std.AsArraySerializerBase.serialize(AsArraySerializerBase.java:86) org.codehaus.jackson.map.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:446) org.codehaus.jackson.map.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:150) org.codehaus.jackson.map.ser.BeanSerializer.serialize(BeanSerializer.java:112) org.codehaus.jackson.map.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:446) org.codehaus.jackson.map.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:150) org.codehaus.jackson.map.ser.BeanSerializer.serialize(BeanSerializer.java:112) org.codehaus.jackson.map.ser.StdSerializerProvider._serializeValue(StdSerializerProvider.java:610) org.codehaus.jackson.map.ser.StdSerializerProvider.serializeValue(StdSerializerProvider.java:256) org.codehaus.jackson.map.ObjectMapper.writeValue(ObjectMapper.java:1613) org.springframework.http.converter.json.MappingJacksonHttpMessageConverter.writeInternal(MappingJacksonHttpMessageConverter.java:191) org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:179) org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:148) org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:90) org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:189) org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:69) org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:122) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745) org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686) org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80) org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925) org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856) org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936) org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:827) javax.servlet.http.HttpServlet.service(HttpServlet.java:621) org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812) javax.servlet.http.HttpServlet.service(HttpServlet.java:722) 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$VirtualFilterChain.doFilter(FilterChainProxy.java:342) org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54) org.springframework.security.web.FilterChainProxy$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:183) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105) org.springframework.security.web.FilterChainProxy$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:346) org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:259)note The full stack trace of the root cause is available in the Apache Tomcat/7.0.32 logs.Apache Tomcat/7.0.32