Implementation of the {@link Session Session} interface that proxies another <code>Session</code>, but does not allow any 'write' operations to the underlying session. It allows 'read' operations only. <p/> The <code>Session</code> write operations are defined as follows. A call to any of these methods on this proxy will immediately result in an {@link InvalidSessionException} being thrown: <ul> <li>{@link Session#setTimeout(long) Session.setTimeout(long)}</li> <li>{@link Session#touch() Session.touch()}</li> <li>{@link Session#stop() Session.stop()}</li> <li>{@link Session#setAttribute(Object, Object) Session.setAttribute(key,value)}</li> <li>{@link Session#removeAttribute(Object) Session.removeAttribute(key)}</li> </ul> Any other method invocation not listed above will result in a corresponding call to the underlying <code>Session</code>.