title: best approach to do jsf form validation
body: <p>If I have many input controls in a form (There are separate validators for each of these input controls - like required,length and so on ) , there is a command button which submits the form and calls an action method. The requirement is - though the input control values are , say , individually okay - the combination of these values should be okay to process them together after the form submission - Where do i place the code to validate them together?</p>
  
  <p>1) Can i add a custom validator for the command button and validate the combination together? like  <code>validate(FacesContext arg0, UIComponent arg1, Object value)</code> but even then I will not have values of the other input controls except for the command button's/component's value right ?</p>
  
  <p>2) can i do the validation of the combination in the action method and add validation messages using <code>FacesMessage</code> ?</p>
  
  <p>or do you suggest any other approach?</p>
  
  <p>Thanks for your time.</p>