org.mule.module.xml.internal.xpath

Class XPathEvaluator

java.lang.Object

org.mule.module.xml.internal.xpath.XPathEvaluator

All Implemented Interfaces:

XPathVariableResolver

public class XPathEvaluator
extends Object
implements XPathVariableResolver

Evaluates XPath expressions using the JAXP API (JSR-206).

Each instance accepts one XPath expression and keeps a compiled version of it for better performance.

This evaluator is reusable, as long as the reset() method is invoked in between evaluations. It is not thread-safe though.

It also implements the XPathVariableResolver interface in order to bind contextProperties to variables defined in the XPath script.

Since:

1.0.

Constructor Summary

Constructors

Constructor and Description
XPathEvaluator(String expression, XPathFactory xpathFactory, Collection<NamespaceMapping> namespaces) Creates a new instance

Method Summary

Modifier and Type	Method and Description
List<String>	evaluate(Node input, Map<String,Object> contextProperties) Evaluates the expression on the input node, using the given contextProperties.
XPathEvaluator	keepingTrailingNewlines(boolean shouldKeepTrailingNewlines)
void	reset() Invoke this method in between invocations of the evaluate(Node, Map) method in order to reuse this instance
Object	resolveVariable(QName variableName) Resolves the given variable against the context properties passed on the evaluate(Node, Map) method

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

XPathEvaluator

public XPathEvaluator(String expression,
                      XPathFactory xpathFactory,
                      Collection<NamespaceMapping> namespaces)

Creates a new instance

Parameters:

expression - the xpath expression

xpathFactory - the XPathFactory used to compile the expression

namespaces - namespace mappings

Method Detail

evaluate

public List<String> evaluate(Node input,
                             Map<String,Object> contextProperties)

Evaluates the expression on the input node, using the given contextProperties.

After invoking this method, the consumer MUST invoke the reset() method in order to reuse this evaluator.

Parameters:

input - the base node of the evaluation

contextProperties - context properties

Returns:

a List of strings with the matching elements

resolveVariable

public Object resolveVariable(QName variableName)

Resolves the given variable against the context properties passed on the evaluate(Node, Map) method

Specified by:

resolveVariable in interface XPathVariableResolver

Parameters:

variableName - the variable name

Returns:

the variable value. Might be null

reset

public void reset()

Invoke this method in between invocations of the evaluate(Node, Map) method in order to reuse this instance

keepingTrailingNewlines

public XPathEvaluator keepingTrailingNewlines(boolean shouldKeepTrailingNewlines)