Gente, estou usando Spring Boot numa aplicação, mas não consigo resolver essa exceção… Alguém pode me ajudar? 
java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'singlepagemodel' available as request attribute
at org.springframework.web.servlet.support.BindStatus.<init>(BindStatus.java:153) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.web.servlet.support.RequestContext.getBindStatus(RequestContext.java:903) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.thymeleaf.spring5.context.webmvc.SpringWebMvcThymeleafRequestContext.getBindStatus(SpringWebMvcThymeleafRequestContext.java:227) ~[thymeleaf-spring5-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.spring5.util.FieldUtils.getBindStatusFromParsedExpression(FieldUtils.java:306) ~[thymeleaf-spring5-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.spring5.util.FieldUtils.getBindStatus(FieldUtils.java:253) ~[thymeleaf-spring5-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.spring5.util.FieldUtils.getBindStatus(FieldUtils.java:240) ~[thymeleaf-spring5-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.spring5.util.FieldUtils.getBindStatus(FieldUtils.java:227) ~[thymeleaf-spring5-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.spring5.util.FieldUtils.checkErrors(FieldUtils.java:212) ~[thymeleaf-spring5-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.spring5.util.FieldUtils.hasErrors(FieldUtils.java:71) ~[thymeleaf-spring5-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.spring5.expression.Fields.hasErrors(Fields.java:58) ~[thymeleaf-spring5-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_181]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_181]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_181]
at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_181]
at org.springframework.expression.spel.support.ReflectiveMethodExecutor.execute(ReflectiveMethodExecutor.java:126) ~[spring-expression-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.expression.spel.ast.MethodReference.getValueInternal(MethodReference.java:138) ~[spring-expression-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.expression.spel.ast.MethodReference.access$000(MethodReference.java:54) ~[spring-expression-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.expression.spel.ast.MethodReference$MethodValueRef.getValue(MethodReference.java:390) ~[spring-expression-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.expression.spel.ast.CompoundExpression.getValueInternal(CompoundExpression.java:89) ~[spring-expression-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.expression.spel.ast.SpelNodeImpl.getValue(SpelNodeImpl.java:111) ~[spring-expression-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:328) ~[spring-expression-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.thymeleaf.spring5.expression.SPELVariableExpressionEvaluator.evaluate(SPELVariableExpressionEvaluator.java:263) ~[thymeleaf-spring5-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.standard.expression.VariableExpression.executeVariableExpression(VariableExpression.java:166) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.standard.expression.SimpleExpression.executeSimple(SimpleExpression.java:66) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.standard.expression.Expression.execute(Expression.java:109) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.standard.expression.Expression.execute(Expression.java:138) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.standard.expression.Expression.execute(Expression.java:125) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.standard.processor.StandardIfTagProcessor.isVisible(StandardIfTagProcessor.java:59) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.standard.processor.AbstractStandardConditionalVisibilityTagProcessor.doProcess(AbstractStandardConditionalVisibilityTagProcessor.java:61) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.processor.element.AbstractAttributeTagProcessor.doProcess(AbstractAttributeTagProcessor.java:74) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.processor.element.AbstractElementTagProcessor.process(AbstractElementTagProcessor.java:95) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.util.ProcessorConfigurationUtils$ElementTagProcessorWrapper.process(ProcessorConfigurationUtils.java:633) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.engine.ProcessorTemplateHandler.handleOpenElement(ProcessorTemplateHandler.java:1314) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.engine.TemplateHandlerAdapterMarkupHandler.handleOpenElementEnd(TemplateHandlerAdapterMarkupHandler.java:304) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.templateparser.markup.InlinedOutputExpressionMarkupHandler$InlineMarkupAdapterPreProcessorHandler.handleOpenElementEnd(InlinedOutputExpressionMarkupHandler.java:278) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.standard.inline.OutputExpressionInlinePreProcessorHandler.handleOpenElementEnd(OutputExpressionInlinePreProcessorHandler.java:186) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.templateparser.markup.InlinedOutputExpressionMarkupHandler.handleOpenElementEnd(InlinedOutputExpressionMarkupHandler.java:124) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.attoparser.HtmlElement.handleOpenElementEnd(HtmlElement.java:109) ~[attoparser-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.attoparser.HtmlMarkupHandler.handleOpenElementEnd(HtmlMarkupHandler.java:297) ~[attoparser-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.attoparser.MarkupEventProcessorHandler.handleOpenElementEnd(MarkupEventProcessorHandler.java:402) ~[attoparser-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.attoparser.ParsingElementMarkupUtil.parseOpenElement(ParsingElementMarkupUtil.java:159) ~[attoparser-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.attoparser.MarkupParser.parseBuffer(MarkupParser.java:710) ~[attoparser-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.attoparser.MarkupParser.parseDocument(MarkupParser.java:301) ~[attoparser-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.attoparser.MarkupParser.parse(MarkupParser.java:257) ~[attoparser-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parse(AbstractMarkupTemplateParser.java:230) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.templateparser.markup.AbstractMarkupTemplateParser.parseStandalone(AbstractMarkupTemplateParser.java:100) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.engine.TemplateManager.parseAndProcess(TemplateManager.java:666) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1098) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.TemplateEngine.process(TemplateEngine.java:1072) ~[thymeleaf-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.spring5.view.ThymeleafView.renderFragment(ThymeleafView.java:362) ~[thymeleaf-spring5-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.thymeleaf.spring5.view.ThymeleafView.render(ThymeleafView.java:189) ~[thymeleaf-spring5-3.0.10.RELEASE.jar:3.0.10.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1325) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1069) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1008) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:806) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.34.jar:8.5.34]
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [na:1.8.0_181]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [na:1.8.0_181]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.34.jar:8.5.34]
at java.lang.Thread.run(Unknown Source) [na:1.8.0_181]
Seguem meus códigos:
Classe SinglePageController.java
package com.page.controllers;
import javax.validation.Valid;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;
import com.page.models.SinglePageModel;
import com.page.repositories.SinglePageRepository;
@Controller
@RequestMapping("/pages")
public class SinglePageController {
@Autowired
private SinglePageRepository spr;
@GetMapping("/new-page")
public String newPage(@ModelAttribute SinglePageModel singlePageModel) {
return "pages/form-page";
}
@PostMapping(params="page")
public ModelAndView newHotSite(@Valid SinglePageModel singlePageModel, BindingResult result, RedirectAttributes redirect) {
if(result.hasErrors()) {
return new ModelAndView("/new-page","formSinglePageErros", result.getAllErrors());
}
singlePageModel = this.spr.save(singlePageModel);
redirect.addFlashAttribute("globalMessage","HotSite criado com sucesso");
return new ModelAndView("redirect:/" + "/new-page");
}
}
Arquivo SinglePageModel.java:
package com.page.models;
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.validation.constraints.NotNull;
import org.hibernate.validator.constraints.Length;
@Entity(name="SinglePageModel")
@Table(name="singlepagemodel")
public class SinglePageModel implements Serializable{
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;
@NotNull
@Column(length=150)
@Length(min=2, max=150, message="O título da página deve ter entre {min} e {max} caracteres.")
private String pagetitle;
@NotNull
@Column(length=250)
@Length(min=2, max=250, message="O subtítulo da página, caso preenchido, deve ter entre {min} e {max} caracteres.")
private String pagesubtitle;
@NotNull
@Column(length=1000)
@Length(min=140, max=1000, message="A história deve ter entre {min} e {max} caracteres.")
private String historytext;
/*Getters and Setters*/
}
Arquivo SinglePageRepository.java:
package com.page.repositories;
import org.springframework.data.jpa.repository.JpaRepository;
import com.page.models.SinglePageModel;
public interface SinglePageRepository extends JpaRepository<SinglePageModel, Long> {
}
Arquivo form-page.html:
<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org"
xmlns:layout="http://www.ultraq.net.nz/thymeleaf/layout" layout:decorate="~{Layout}">
<head>
<meta charset="UTF-8">
</head>
<body>
<h1 layout:fragment="header">Personalize seu Site</h1>
<div layout:fragment="content">
<div class="alert alert-success" th:if="${globalMessage}" th:text="${globalMessage}">mensagem</div>
<form id="hotsite" th:action="@{/pages/(page)}" th:object="${singlepagemodel}" action="#" method="post">
<p>*Todos os campos são obrigatórios</p>
<div th:if="${#fields.hasErrors('*')}">
<p class="alert alert-danger" role="alert" th:each="error : ${#fields.errors('*')}" th:text="${error}">Erro de validação</p>
</div>
<input type="hidden" th:field="*{id}" th:class="${#fields.hasErrors('id')} ? 'field-error'" />
<div class="form-group">
<label for="pagetitle">Título:*</label>
<input type="text" class="form-control" id="pagetitle" placeholder="Digite o título da página..." th:field="*{pagetitle}" th:classappend="${#fields.hasErrors('pagetitle')} ? 'field-error'" />
<small id="helpname" class="form-text text-muted">
Exemplo: Ana e Renato
</small>
</div>
<div class="form-group">
<label for="pagesubtitle">Subtítulo(Opcional):</label>
<input type="text" class="form-control" id="pagesubtitle" placeholder="Digite seu subtítulo da página(opcional)..." th:field="*{pagesubtitle}" th:classappend="${#fields.hasErrors('pagesubtitle')} ? 'field-error'" />
<small id="help" class="form-text text-muted">
Exemplo: Nosso momento chegou!
</small>
</div>
<div class="form-group">
<label for="historytext">Nossa história...*</label>
<textarea class="form-control" id="historytext" rows="3" placeholder="Conte um pouco da sua história..." th:field="*{historytext}" th:classappend="${#fields.hasErrors('historytext')} ? 'field-error'" >
</textarea>
<small id="ajudaMensagem" class="form-text text-muted">
Sua história deve ter entre 2 e 1000 caracteres.
</small>
</div>
<div class="form-group float-right">
<a th:href="@{/}" href="index.html"><input type="button" class="btn btn-dark" value="Voltar" /></a>
<input type="reset" class="btn btn-dark" value="Limpar" />
<input type="submit" class="btn btn-dark" value="Enviar" />
</div>
</form>
</div>
</body>
</html>
Arquivo applications.properties:
#Configurações de bancos de dados
spring.jpa.hibernate.ddl-auto=create
spring.datasource.url=jdbc:mysql://localhost/banco_de_teste?useSSL=false
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.username=meuusuario
spring.datasource.password=minhasenha