Cool, glad your problems fixed. Its easy to make a slow XPath expression that has to trawl the entire document. Using // in an XPath expression is probably the easiest way to slow things down :-)
James ------- http://radio.weblogs.com/0112098/ ----- Original Message ----- From: "Bram Huenaerts" <[EMAIL PROTECTED]> To: "DOM4J-user (E-mail)" <[EMAIL PROTECTED]> Sent: Thursday, August 29, 2002 8:03 AM Subject: RE: [dom4j-user] DOMReader related problem (Performace) > Hi, > > sorry, but the problem is already solved. > After debugging I found out that it was another problem > The problem was that I used XPath on a big XML Document (>1MB) > When i used the code below, it was very ,very slow. > > <code> > XPath xpathSelector = DocumentHelper.createXPath("//collection/item[" + > index + "]"); > java.util.List nodes = xpathSelector.selectNodes(document); > Element element = (Element) nodes.get(0); > String item = element.asXML(); > byte[] bytes = item.getBytes(); > ... > </code> > > After changing the XPath to this code, the performance increased. > > <code> > XPath xpathSelector = DocumentHelper.createXPath("/*/item[" + index + "]"); > </code> > > Thanks > > -----Original Message----- > From: James Strachan [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, August 28, 2002 5:13 PM > To: David Hooker; 'DOM4J-user (E-mail)' > Subject: Re: [dom4j-user] DOMReader related problem (Performace) > > > From: "David Hooker" <[EMAIL PROTECTED]> > > How do you cache the parser? > > Just like the example I coded below. i.e. by reusing the same SAXReader > instance in the same thread. Creating a new instance each time results in a > new underlying SAX parser, the XMLReader, being created which tends to > reinitialize the underlying parser each time. > > Another approach to using ThreadLocal could be to use an object pool > implementation. > > > e.g. if using the dom4j SAXReader, it can often be useful to use > > ThreadLocal > > to pool them by thread. e.g. > > > > ThreadLocal pool= new ThreadLocal() { > > protected Object initialValue() { > > return new SAXReader(); > > } > > }; > > > > ... > > SAXReader reader = (SAXReader) pool.get(); > > reader.parse( "foo.xml" ); > > > James > ------- > http://radio.weblogs.com/0112098/ > > > __________________________________________________ > Do You Yahoo!? > Everything you'll ever need on one web page > from News and Sport to Email and Music Charts > http://uk.my.yahoo.com > > > ------------------------------------------------------- > This sf.net email is sponsored by: Jabber - The world's fastest growing > real-time communications platform! Don't just IM. Build it in! > http://www.jabber.com/osdn/xim > _______________________________________________ > dom4j-user mailing list > [EMAIL PROTECTED] > https://lists.sourceforge.net/lists/listinfo/dom4j-user > > > ------------------------------------------------------- > This sf.net email is sponsored by:ThinkGeek > Welcome to geek heaven. > http://thinkgeek.com/sf > _______________________________________________ > dom4j-user mailing list > [EMAIL PROTECTED] > https://lists.sourceforge.net/lists/listinfo/dom4j-user > __________________________________________________ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf _______________________________________________ dom4j-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dom4j-user
