Citation:
Retrieve the value of the specified bean property, and render it to the current JspWriter as a String by the ways:
* If format attribute exists then value will be formatted on base of format string from format attribute and default system locale.
* If in resources exists format string for value data type (view format attribute description) then value will be formatted on base of format string from resources. Resources bundle and target locale can be specified with bundle and locale attributes. If nothing specified then default resource bundle and current user locale will be used.
*If there is a PropertyEditor configured for the property value's class, the getAsText() method will be called.
Otherwise, the usual toString() conversions will be applied.
Donc, dans le cas où la propriété est de type int, il cherche à la convertir en String.
Citation:
Specifies the format string to use to convert bean or property value to the String. If nothing specified, then default format string for value data type will be searched in message resources by according key.
Ceci explique pourquoi il a besoin du fichier ressources.