@javax.inject.Named
@javax.enterprise.context.RequestScoped
ProductView

<ui:fragment rendered="#{cartView.getAmountProduct(productView.id) gt 0}">
...
</ui:fragment>

<ui:fragment rendered="#{not empty productView.id and cartView.getAmountProduct(productView.id) gt 0}">
</ui:fragment>

    public Integer getAmountProduct(String id) {
        try {
            return data.getOrDefault(Integer.parseInt(id), 0);
        } catch (NumberFormatException e) {
            e.printStackTrace();
            return 0;
        }
    }