thymeleaf not getting data from controller

I am trying to send the username dynamically to the navbar whenever a user log in. I am new to spring boot and to my best knowledge everything looks fine but when i try to run, it throws a thymeleaf exception.

I have made a model object and i am trying to send the data using setAttribute method but it does not seem to be working. I am not able to understand the thymeleaf error that is being produced. Any help would be really appreciated.

Error

Whitelabel Error Page This application has no explicit mapping for /error, so you are seeing this as a fallback. Sat Apr 10 02:24:05 IST 2021 There was an unexpected error (type=Internal Server Error, status=500). An error happened during template parsing (template: "class path resource [templates/dashboard.html]") org.thymeleaf.exceptions.TemplateInputException: An error happened during template parsing (template: "class path resource [templates/dashboard.html]") at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parse(AbstractMarkupTemplateParser.java:241) at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parseStandalone(AbstractMarkupTemplateParser.java:100) at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:666) at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1098) at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1072) at org.thymeleaf.spring5.view.ThymeleafView.renderFragment(ThymeleafView.java:366) at org.thymeleaf.spring5.view.ThymeleafView.render(ThymeleafView.java:190) at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1393) at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1138) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1077) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:962) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) at javax.servlet.http.HttpServlet.service(HttpServlet.java:626) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:327) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:115) at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:81) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:119) at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:126) at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:81) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:105) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:149) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:218) at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:212) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:103) at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:89) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:90) at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:75) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:110) at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:80) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:55) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:211) at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:183) at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:358) at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:271) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:893) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1707) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.base/java.lang.Thread.run(Thread.java:832) Caused by: org.attoparser.ParseException: Exception evaluating SpringEL expression: "user.office_name" (template: "dashboard" - line 43, col 65) at org.attoparser.MarkupParser.parseDocument(MarkupParser.java:393) at org.attoparser.MarkupParser.parse(MarkupParser.java:257) at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parse(AbstractMarkupTemplateParser.java:230) ... 86 more Caused by: org.thymeleaf.exceptions.TemplateProcessingException: Exception evaluating SpringEL expression: "user.office_name" (template: "dashboard" - line 43, col 65) at org.thymeleaf.spring5.expression.SPELVariableExpressionEvaluator.evaluate(SPELVariableExpressionEvaluator.java:292) at org.thymeleaf.standard.expression.VariableExpression.executeVariableExpression(VariableExpression.java:166) at org.thymeleaf.standard.expression.SimpleExpression.executeSimple(SimpleExpression.java:66) at org.thymeleaf.standard.expression.Expression.execute(Expression.java:109) at org.thymeleaf.standard.expression.Expression.execute(Expression.java:138) at org.thymeleaf.standard.processor.AbstractStandardExpressionAttributeTagProcessor.doProcess(AbstractStandardExpressionAttributeTagProcessor.java:144) at org.thymeleaf.processor.element.AbstractAttributeTagProcessor.doProcess(AbstractAttributeTagProcessor.java:74) at org.thymeleaf.processor.element.AbstractElementTagProcessor.process(AbstractElementTagProcessor.java:95) at org.thymeleaf.util.ProcessorConfigurationUtils$ElementTagProcessorWrapper.process(ProcessorConfigurationUtils.java:633) at org.thymeleaf.engine.ProcessorTemplateHandler.handleOpenElement(ProcessorTemplateHandler.java:1314) at org.thymeleaf.engine.TemplateHandlerAdapterMarkupHandler.handleOpenElementEnd(TemplateHandlerAdapterMarkupHandler.java:304) at org.thymeleaf.templateparser.markup.InlinedOutputExpressionMarkupHandler$InlineMarkupAdapterPreProcessorHandler.handleOpenElementEnd(InlinedOutputExpressionMarkupHandler.java:278) at org.thymeleaf.standard.inline.OutputExpressionInlinePreProcessorHandler.handleOpenElementEnd(OutputExpressionInlinePreProcessorHandler.java:186) at org.thymeleaf.templateparser.markup.InlinedOutputExpressionMarkupHandler.handleOpenElementEnd(InlinedOutputExpressionMarkupHandler.java:124) at org.attoparser.HtmlElement.handleOpenElementEnd(HtmlElement.java:109) at org.attoparser.HtmlMarkupHandler.handleOpenElementEnd(HtmlMarkupHandler.java:297) at org.attoparser.MarkupEventProcessorHandler.handleOpenElementEnd(MarkupEventProcessorHandler.java:402) at org.attoparser.ParsingElementMarkupUtil.parseOpenElement(ParsingElementMarkupUtil.java:159) at org.attoparser.MarkupParser.parseBuffer(MarkupParser.java:710) at org.attoparser.MarkupParser.parseDocument(MarkupParser.java:301) ... 88 more Caused by: org.springframework.expression.spel.SpelEvaluationException: EL1007E: Property or field 'office_name' cannot be found on null at org.springframework.expression.spel.ast.PropertyOrFieldReference.readProperty(PropertyOrFieldReference.java:213) at org.springframework.expression.spel.ast.PropertyOrFieldReference.getValueInternal(PropertyOrFieldReference.java:104) at org.springframework.expression.spel.ast.PropertyOrFieldReference.access$000(PropertyOrFieldReference.java:51) at org.springframework.expression.spel.ast.PropertyOrFieldReference$AccessorLValue.getValue(PropertyOrFieldReference.java:406) at org.springframework.expression.spel.ast.CompoundExpression.getValueInternal(CompoundExpression.java:92) at org.springframework.expression.spel.ast.SpelNodeImpl.getValue(SpelNodeImpl.java:112) at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:337) at org.thymeleaf.spring5.expression.SPELVariableExpressionEvaluator.evaluate(SPELVariableExpressionEvaluator.java:265) ... 107 more 

Controller

@Controller @RequestMapping("/user") public class UserController { @Autowired private UserRepository userRepository; @RequestMapping("/dashboard") public String dashboard(Model model,Principal principal) { String userName = principal.getName(); System.out.println("USERNAME"+userName); User user = userRepository.getUserBYUserName(userName); System.out.println("USER"+user); model.addAttribute("User",user); return "dashboard"; } } 

HTML Page

 <nav class="navbar navbar-expand-lg navbar-dark bg-secondary"> <a class="navbar-brand" th:href="@{/}" href="#"> <img src="" class="logo" th:src="@{/image/logo.png}" alt="logo"> Assam Power Distribution Company Limited</a> <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <div class="collapse navbar-collapse" id="navbarSupportedContent"> <ul class="navbar-nav ml-auto"> <li class="nav-item active"> <a class="nav-link" th:href="@{/}" href="">Home </a> </li> <li class="nav-item"> <a class="nav-link" href="" modelAttribute="user"><span th:text="${user.office_name}" ></span></a> </li> <li class="nav-item"> <a class="nav-link" th:href="@{/logout}" href="">Logout</a> </li> </ul> </div> </nav> 

User Model

@Entity public class User { @Id @GeneratedValue(strategy = GenerationType.AUTO) private int Id; @NotBlank(message = "Name field is required !!") private String office_name; private String higher_office; private String password; private String Office_address; private int no_of_consumers;