f this type are either sent to an object that implements <a href="../../../javax/servlet/http/HttpSessionBindingListener.html" title="interface in javax.servlet.http"><code>HttpSessionBindingListener</code></a> when it is bound
 or unbound from a session, or to a <a href="../../../javax/servlet/http/HttpSessionAttributeListener.html" title="interface in javax.servlet.http"><code>HttpSessionAttributeListener</code></a> that has been configured in the deployment
 descriptor when any attribute is bound, unboun