Sobre o artigo do DEVMEDIA (Java WEB: Criando uma tela de Login com JPA, JSF, PrimeFaces e MySQL)

HTTP Status 500 - /login.xhtml @15,92 value="#{loginMB.usuario.nomeUsuario}": Target Unreachable, identifier 'loginMB' resolved to null


type Exception report

message /login.xhtml @15,92 value="#{loginMB.usuario.nomeUsuario}": Target Unreachable, identifier 'loginMB' resolved to null

description The server encountered an internal error that prevented it from fulfilling this request.

exception 
javax.servlet.ServletException: /login.xhtml @15,92 value="#{loginMB.usuario.nomeUsuario}": Target Unreachable, identifier 'loginMB' resolved to null
	javax.faces.webapp.FacesServlet.service(FacesServlet.java:606)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)



root cause 
javax.el.PropertyNotFoundException: /login.xhtml @15,92 value="#{loginMB.usuario.nomeUsuario}": Target Unreachable, identifier 'loginMB' resolved to null
	com.sun.faces.facelets.el.TagValueExpression.getType(TagValueExpression.java:100)
	org.primefaces.util.ComponentUtils.getConverter(ComponentUtils.java:146)
	org.primefaces.renderkit.InputRenderer.getConvertedValue(InputRenderer.java:175)
	javax.faces.component.UIInput.getConvertedValue(UIInput.java:1030)
	javax.faces.component.UIInput.validate(UIInput.java:960)
	javax.faces.component.UIInput.executeValidate(UIInput.java:1233)
	javax.faces.component.UIInput.processValidators(UIInput.java:698)
	javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214)
	javax.faces.component.UIForm.processValidators(UIForm.java:253)
	javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214)
	javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214)
	javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:1172)
	com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:76)
	com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
	com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
	javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)



note The full stack trace of the root cause is available in the Apache Tomcat/7.0.53 logs.


Apache Tomcat/7.0.53