Liyaquat Ali mentioned that
${request.person.age} it prints nothing.
${request.person["age"]} it prints nothing.
Note that there is no implicit object as 'request' in EL. Instead it has 'requestScope' as an implicit object [JSP implicit object 'request' is not the same as this 'requestScope']. In your code, it prints nothing because
1. the EL looks for 'request' in any one of the JSP scopes.
2. It couldn't find any. It returns null.
3. Since EL is null friendly, it promptly prints nothing.
Try using ${requestScope.person.age}, you would throw the same exception.