title: How to properly use isUserInRole(role)
body: <p>To prevent a user role from performing an action. </p>
  
  <ol>
  <li>Example 1: The role "administrator" 
  is the only role allowed to perform 
  destroy action.</li>
  <li>Example 2: Any role different from "guest" can perform CREATE action.</li>
  </ol>
  
  <p>In a real case, I have this:</p>
  
  <pre><code>public String delete() {
   if(FacesContext.getCurrentInstance().getExternalContext().isUserInRole("administrator"){
     //.....the action to perform
   }
   return "Denied";
  }
  </code></pre>
  
  <p>I wish I could use the annotation <code>@RolesAllowed()</code> of EJB yet I am not using EJB but ManagedBeans.
  So the question is: Is there any way to use many roles at the same time? Some workaround!
  Example: If an action must be allowed to 3 roles (administrator, moderator, manager). I am obliged to do :</p>
  
  <pre><code>if (FacesContext.getCurrentInstance().getExternalContext().isUserInRole("administrator")
      || FacesContext.getCurrentInstance().getExternalContext().isUserInRole("manager") 
      || .....) {
    //....
  }
  </code></pre>
  
  <p>And it is a pain to reproduce on all the methods. Something like hundreds of methods :(</p>