title: Convert h:selectBooleanCheckbox value between boolean and String
body: <p>I have a backing bean containing a field <code>creditCard</code> which can have two string values <code>y</code> or <code>n</code> populated from the DB. I would like to display this in checkbox so that <code>y</code> and <code>n</code> gets converted to <code>boolean</code>.</p>
  
  <p>How can I implement it? I can't use a custom converter as <code>getAsString()</code> returns <code>String</code> while rendering the response whereas I need a <code>boolean</code>.</p>