Class SumFunctionCall

java.lang.Object
org.exolab.adaptx.xpath.expressions.PrimaryExpr
org.exolab.adaptx.xpath.expressions.FunctionCall
org.exolab.adaptx.xpath.functions.FunctionCallImpl
org.exolab.adaptx.xpath.functions.SumFunctionCall
All Implemented Interfaces:
Parameters, XPathExpression
public class SumFunctionCall extends FunctionCallImpl
A class that represents the XPath 1.0 sum function call. The Sum function takes as an argument an experession which evaluates to a node-set. Each node in the node-set will have it's string-value converted into a number. Each resulting number will then added together to compute the sum. Nodes whose string value is the empty-string will be ignored. If any node within the node-set has a non-zero length string value that cannot be sucessfully converted to a number, an XPathException will be thrown.
Version:
$Revision: 3736 $
Author:
Keith Visco

  • Constructor Details

    • SumFunctionCall

      public SumFunctionCall()
      Creates a new SumFunctionCall

  • Method Details

    • evaluate

      public XPathResult evaluate(XPathContext context) throws XPathException
      Evaluates the expression and returns the XPath result.
      Parameters:
      context - The XPathContext to use during evaluation.
      Returns:
      The XPathResult (not null).
      Throws:
      XPathException - if an error occured while evaluating this expression.

    • computeSum

      public double computeSum(NodeSet nodeSet) throws XPathException
      Computes the sum of the given NodeSet. The sum is computed by adding up the number values of each node within the node set. If any non-numeric node values are encountered, an XPathException will be thrown.
      Parameters:
      nodeSet - the NodeSet to the compute the sum of
      Returns:
      the sum as a double
      Throws:
      XPathException - when a non-numeric value is encountered.