Validation

<!-- User must input something and -->
<!-- text must be between 2 and 10 chars in length -->
<h:inputText value="#{globalSettingsBean.personName}" required="true">
    <f:validateLength minimum="2" maximum="10"/>
</h:inputText>

<!-- User must input something -->
<!-- and it must be a number between 0 and 100 -->
<h:inputText value="#{globalSettingsBean.personAge}" required="true">
    <f:validateLongRange minimum="0" maximum="100"/>
</h:inputText>

<!-- How to get messages from a jsf properties file AND -->
<!-- How to send a message back to the page -->
// get a reference to properties file to retreive messages
FacesContext context = FacesContext.getCurrentInstance();
ResourceBundle bundle = ResourceBundle.getBundle("game.messages",
    context.getViewRoot().getLocale());
String msg = "";
// if number bigger, get appropriate message
if ( userNumber.intValue() > randomNumber )
    msg = bundle.getString("tryagain_smaller");
else // if number smaller, get appropriate message
    msg = bundle.getString("tryagain_bigger");
// add message to be displayed on the page via <h:messages> tag
context.addMessage (null, new FacesMessage(msg));