XPath Data Model

• evaluate() is declared to return Object.

• Actual return type depends on the result of the XPath expression:

  • number maps to a java.lang.Double

  • string maps to a java.lang.String

  • boolean maps to a java.lang.Boolean

  • node-set maps to an org.w3c.dom.NodeList

• Second argument specifies the return type you want

  • XPathConstants.NODESET

  • XPathConstants.BOOLEAN

  • XPathConstants.NUMBER

  • XPathConstants.STRING

  • XPathConstants.NODE

• If the requested conversion can't be made, evaluate() throws an XPathException.