org.exolab.adaptx.xpath.functions
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
Methods inherited from class java.lang.Object |
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait |
SumFunctionCall
public SumFunctionCall()
- Creates a new SumFunctionCall
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.