[RESOLVIDO] Como validar valores JSF + Primefaces

<p:growl id="growlNewCompromisso" showDetail="true"/>
       <h:form id="cadastroDeCompromisso"> 
            <p:panel header="Nova Compromisso">
                <h:panelGrid columns="2" id="cadCompromisso">
                    <h:outputLabel value="Hora Inicial:* " for="horaInicial"/>
                    <p:calendar id="horaInicial" timeOnly="true" locale="br" pattern="HH:mm" minHour="8" maxHour="18" value="#{beanConsulta.consulta.horaInicial}"
                                required="true" requiredMessage="Preencha o campo Hora Inicial!"/>
                    
                    <h:outputLabel value="Hora Final:* " for="horaFinal"/>
                    <p:calendar id="horaFinal" timeOnly="true" locale="br" pattern="HH:mm" minHour="8" maxHour="18" value="#{beanConsulta.consulta.horaFinal}"
                                required="true" requiredMessage="Preencha o campo Hora Final!"/>
                    
                    <h:outputLabel value="Descrição:* " for="desc"/>
                    <p:inputText id="desc" value="#{beanConsulta.consulta.desc}"
                                 required="true" requiredMessage="Preencha o campo Descrição!"/>

                </h:panelGrid>
                <p:commandButton value="Salvar" update="cadastroDeCompromisso,growlNewCompromisso" action="#{beanConsulta.gravar()}"/>
             </p:panel>
       </h:form>