JDOM2

• java - Default XML namespace, JDOM, and XPath - Stack Overflow
• java - JDOM 2 and xpath - Stack Overflow
• Parsing an XML Document with XPath - O'Reilly Media
• XPathBuilder (JDOM v2.0.5)
• XPathFactory (JDOM v2.0.5)
• XPathExpression (JDOM v2.0.5)