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10.5. Packaging Listeners with Tag Libraries

JSP tag libraries (Section 3.7, Chapter 11) provide a great way of encapsulating content that will be accessed by multiple JSP pages. But what if that content depends on life-cycle event listeners? If the listener and listener-class elements of web.xml were the only option for declaring listeners, tag library maintenance would be much more difficult. Normally, the user of a tag library can deploy it by simply dropping a JAR file in WEB-INF/lib and putting a TLD file in WEB-INF. Users of the tag libraries need no knowledge of the individual classes within the library, only of the tags that the library defines. But if the tag libraries used listeners, users of the libraries would need to discover the ...