In the Internet era, xml files play a role in saving and transmitting data. The Soap protocol communicates information through Xml, and the database is accessed through Xml files, etc. So how to quickly obtain the required information from an XML file? We know that both Java's JAXP and Microsoft.Net have Xml parsers. Microsoft.Net analyzes while reading, while JAXP reads into memory and then analyzes (there is also an event mechanism to read). In short, It is not conducive to fast reading. Based on this, both Microsoft.Net and JAXP provide the XPATH mechanism to quickly locate the required nodes in the XML file. For example, there is an XML file: booksort.xml:
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