On Thu, 13 Feb 2003, Erik Price wrote:
> Date: Thu, 13 Feb 2003 11:56:54 -0500 > From: Erik Price <[EMAIL PROTECTED]> > Reply-To: Jakarta Commons Users List <[EMAIL PROTECTED]> > To: Jakarta Commons Users List <[EMAIL PROTECTED]> > Subject: [Digester] The purpose of digester > > Does Digester have a dedicated "purpose", or is it intended to be a > flexible high-level API for accessing XML data (for any purpose)? > The original motivation for the code in Digester was to read configuration files with relatively complex internal structure -- most particularly, things like web.xml and server.xml in Tomcat. The Digester code itself was factored out of Struts because it turned out to be generally useful for many XML --> Object conversions. One way to think about Digester is a higher level abstraction over SAX parsing (which is what it does under the covers). It's especially nice for applications where you just want to pull a few relevant things out of a structure, or you want to take advantage of things like the SetPropertiesRule, which automatically maps XML attributes into calls to the setter methods of a JavaBean. > I'm developing an app that will need to store certain information. I'm > considering using XML just to learn more about some of the issues > involved in using XML for this purpose. Digester is an attractive means > of parsing those files. > Yep. You might also want to look at Betwixst if you have to go the other direction (Object --> XML). > Also, is there a compelling reason to use XML instead of Property files? > One key word: hierarchies. If you're familiar with Tomcat, you've undoubtedly looked at server.xml files that sometimes have nested structures five or six levels deep. With a properties file, you have to use huge long property names to distinguish the fact that you're setting (say) the auto-reload property of web application A instead of web application B. With XML's nesting of elements, the nested elements are naturally scoped to the elements they are nested in, so you can use much shorter names. If the data you are reading isn't really hierarchical (say, the properties you would use to configure a JDBC connection), properties files work fine. If you've got a huge structure with deep relationships, you'll really like XML a lot better. > Just curious! > > Thanks, > > Erik > Craig --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
