Although DOM, SAX, and JDOM provide standard interfaces for most common tasks, there are still several things they don't address. For example, the process of creating a DOMParser object in a Java program differs from one DOM parser to the next. To fix this problem, Sun has released JAXP, the Java API for XML Parsing. This API provides common interfaces for processing XML documents using DOM, SAX, and XSLT.
JAXP provides interfaces such as the DocumentBuilderFactory and the DocumentBuilder that provide a standard interface to different parsers. There are also methods that allow you to control whether the underlying parser is namespace-aware and whether it uses a DTD or schema to validate the XML document.