Описание тега selectsinglenode

.NET
Selects the first XmlNode that matches the XPath expression. Any prefixes found in the XPath expression are resolved using the supplied XmlNamespaceManager.

Namespace:  System.Xml
Assembly:  System.Xml (in System.Xml.dll)

http://msdn.microsoft.com/en-us/library/h0hw012b%28v=vs.110%29.aspx

Java

public abstract java.lang.Object selectSingleNode(java.lang.Object context)
                                           throws JDOMException

Evaluates the wrapped XPath expression and returns the first entry in the list of selected nodes (or atomics). Parameters: context - the node to use as context for evaluating the XPath expression. Returns: the first selected item, which may be of types: Element, Attribute, Text, CDATA, Comment, ProcessingInstruction, Boolean, Double, String, or null if no item was selected. Throws: JDOMException - if the evaluation of the XPath expression on the specified context failed.

http://www.jdom.org/docs/apidocs.1.1/org/jdom/xpath/XPath.html