Meu código deu seguinte erro abaixo ao tentar editar o produto.
Type Exception Report
Message org.apache.jasper.el.JspPropertyNotFoundException: /WEB-INF/views/produto/form.jsp(64,6) '${produto.categorias}' Property [categorias] not found on type [br.com.caelum.model.Produto]
Description The server encountered an unexpected condition that prevented it from fulfilling the request.
Exception
org.apache.jasper.JasperException: org.apache.jasper.el.JspPropertyNotFoundException: /WEB-INF/views/produto/form.jsp(64,6) '${produto.categorias}' Property [categorias] not found on type [br.com.caelum.model.Produto]
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:565)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:481)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:386)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330)
javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:168)
org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1244)
org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1027)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:971)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857)
javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause
org.apache.jasper.el.JspPropertyNotFoundException: /WEB-INF/views/produto/form.jsp(64,6) '${produto.categorias}' Property [categorias] not found on type [br.com.caelum.model.Produto]
org.apache.jasper.el.JspValueExpression.getValue(JspValueExpression.java:120)
org.apache.jsp.WEB_002dINF.views.produto.form_jsp._jspx_meth_c_005fforEach_005f2(form_jsp.java:692)
org.apache.jsp.WEB_002dINF.views.produto.form_jsp._jspx_meth_c_005fforEach_005f1(form_jsp.java:624)
org.apache.jsp.WEB_002dINF.views.produto.form_jsp._jspService(form_jsp.java:321)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:443)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:386)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:330)
javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:168)
org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1244)
org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1027)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:971)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857)
javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Note The full stack trace of the root cause is available in the server logs.
Apache Tomcat/8.5.31