JAXP: API or abstraction?
by, 04-27-2012 at 05:06 PM (542 Views)
Strictly speaking, JAXP is an API, but it is more accurately called an abstraction layer. It doesn't provide a new means of parsing XML, nor does it add to SAX or DOM, or give new functionality to Java and XML handling. (If you're in disbelief at this point, you're reading the right article.) Instead, JAXP makes it easier to use DOM and SAX to deal with some difficult tasks. It also makes it possible to handle some vendor-specific tasks that you might encounter when using the DOM and SAX APIs, in a vendor-neutral way.
Without SAX, DOM, or another XML parsing API, you cannot parse XML. I have seen many requests for a comparison of SAX, DOM, JDOM, and dom4j to JAXP, but making such comparisons is impossible because the first four APIs serve a completely different purpose from JAXP. SAX, DOM, JDOM, and dom4j all parse XML. JAXP provides a means of getting to these parsers and the data that they expose, but doesn't offer a new way to parse an XML document. Understanding this distinction is critical if you're going to use JAXP correctly. It will also most likely put you miles ahead of many of your fellow XML developers.