Package net.sf.saxon.sxpath
Class XPathEvaluator
- java.lang.Object
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- net.sf.saxon.sxpath.XPathEvaluator
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public class XPathEvaluator extends java.lang.Object
This class provide a native Saxon API for free-standing evaluation of XPath expressions. Unlike the JAXP API offered byXPathEvaluator
it exposes Saxon classes and interfaces and thus provides a more strongly-typed interface with greater control over the detailed behaviour.- Since:
- 8.4
- Author:
- Michael H. Kay
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Constructor Summary
Constructors Constructor Description XPathEvaluator()
Default constructor.XPathEvaluator(Configuration config)
Construct an XPathEvaluator with a specified configuration.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description NodeInfo
build(javax.xml.transform.Source source)
Deprecated.since 8.9.XPathExpression
createExpression(java.lang.String expression)
Prepare (compile) an XPath expression for subsequent evaluation.XPathExpression
createPattern(java.lang.String pattern)
Prepare (compile) an XSLT pattern for subsequent evaluation.XPathVariable
declareVariable(java.lang.String uri, java.lang.String localName)
Declare a variable, making it available for use within a subsequently-compiled XPath expression.Configuration
getConfiguration()
Get the Configuration in use.Executable
getExecutable()
Get the executableNamespaceResolver
getNamespaceResolver()
Get the external namespace resolver, if one has been set usingsetNamespaceResolver(net.sf.saxon.om.NamespaceResolver)
XPathStaticContext
getStaticContext()
Get the current static context.static void
main(java.lang.String[] args)
For testing onlyvoid
setDefaultElementNamespace(java.lang.String uri)
Set the default namespace for elements and typesvoid
setNamespaceResolver(NamespaceResolver namespaceResolver)
Set the external namespace resolver to be used.void
setStaticContext(XPathStaticContext context)
Set the static context for compiling XPath expressions.void
setStripSpace(boolean strip)
Deprecated.since 8.9.
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Constructor Detail
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XPathEvaluator
public XPathEvaluator()
Default constructor. Creates an XPathEvaluator with a default configuration and name pool. Note that any source documents used by an XPath expression under this XPathEvaluator must be built using theConfiguration
that is implicitly created by this constructor, which is accessible using thegetConfiguration()
method.
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XPathEvaluator
public XPathEvaluator(Configuration config)
Construct an XPathEvaluator with a specified configuration.- Parameters:
config
- the configuration to be used. If the XPathEvaluator is to be used to run schema-aware XPath expressions this must be an instance ofcom.saxonica.validate.SchemaAwareConfiguration
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Method Detail
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getConfiguration
public Configuration getConfiguration()
Get the Configuration in use.- Returns:
- the Saxon configuration
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setStripSpace
public void setStripSpace(boolean strip)
Deprecated.since 8.9. The preferred way to build a source document is to useConfiguration.buildDocument(javax.xml.transform.Source)
Indicate whether all whitespace text nodes in source documents are to be removed. This affects the action of thebuild(javax.xml.transform.Source)
method, and of all other methods that take a Source as input.- Parameters:
strip
- True if all whitespace text nodes are to be stripped from the source document, false otherwise. The default if the method is not called is false.
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build
public NodeInfo build(javax.xml.transform.Source source) throws XPathException
Deprecated.since 8.9. The preferred way to build a source document is to useConfiguration.buildDocument(javax.xml.transform.Source)
Build a source document.This method is retained for backwards compability. The preferred way to build a document tree is to call the method
Configuration.buildDocument(javax.xml.transform.Source)
- Parameters:
source
- a JAXP Source object. This may be any implementation of Source that Saxon recognizes: not only the standard kinds of source such as StreamSource, SAXSource, and DOMSource, but also for example a JDOM or XOM DocumentWrapper. For the way in which the source document is built, seeConfiguration.buildDocument(javax.xml.transform.Source)
- Returns:
- the NodeInfo representing the root of the constructed tree.
- Throws:
XPathException
- if, for example, XML parsing fails.
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declareVariable
public XPathVariable declareVariable(java.lang.String uri, java.lang.String localName)
Declare a variable, making it available for use within a subsequently-compiled XPath expression. The variable may subsequently be assigned a value using the methodXPathDynamicContext.setVariable(XPathVariable, net.sf.saxon.om.ValueRepresentation)
. Any external variable used in an XPath expression must be declared before the XPath expression is compiled.- Parameters:
uri
- The namespace URI of the variable name. Use "" for the null namespace.localName
- The local part of the variable name.- Returns:
- an object representing the variable
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setStaticContext
public void setStaticContext(XPathStaticContext context)
Set the static context for compiling XPath expressions. This provides more detailed control over the environment in which the expression is compiled, for example it allows namespace prefixes to be declared, variables to be bound and functions to be defined. For most purposes, the static context can be defined by providing and tailoring an instance of theIndependentContext
class. Until this method is called, a default static context is used, in which no namespaces are defined other than the standard ones (xml, xslt, and saxon), and no variables or functions (other than the core XPath functions) are available.- Parameters:
context
- the XPath static contextSetting a new static context clears any variables and namespaces that have previously been declared.
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getStaticContext
public XPathStaticContext getStaticContext()
Get the current static context. This will always return a value; if no static context has been supplied by the user, the system will have created its own. A system-created static context will always be an instance ofIndependentContext
- Returns:
- the static context object
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getExecutable
public Executable getExecutable()
Get the executable- Returns:
- the executable. This holds details of function bindings and collations.
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createExpression
public XPathExpression createExpression(java.lang.String expression) throws XPathException
Prepare (compile) an XPath expression for subsequent evaluation.- Parameters:
expression
- The XPath expression to be compiled, supplied as a string.- Returns:
- an XPathExpression object representing the prepared expression
- Throws:
XPathException
- if the syntax of the expression is wrong, or if it references namespaces, variables, or functions that have not been declared.
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createPattern
public XPathExpression createPattern(java.lang.String pattern) throws XPathException
Prepare (compile) an XSLT pattern for subsequent evaluation. The result is an XPathExpression object representing a (pseudo-) expression that when evaluated returns a boolean result: true if the context node matches the pattern, false if it does not.- Parameters:
pattern
- the XSLT pattern to be compiled, supplied as a string- Returns:
- an XPathExpression object representing the pattern, wrapped as an expression
- Throws:
XPathException
- if the syntax of the expression is wrong, or if it references namespaces, variables, or functions that have not been declared.- Since:
- 9.1
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setNamespaceResolver
public void setNamespaceResolver(NamespaceResolver namespaceResolver)
Set the external namespace resolver to be used. The NamespaceResolver is stored as part of the static context. It overrides any namespaces declared directly using declareNamespace on the staticContext object- Parameters:
namespaceResolver
- The namespace resolver, which maintains a mapping of prefixes to URIs. Any namespace prefix used in the XPath expression is resolved using this namespaceResolver.
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getNamespaceResolver
public NamespaceResolver getNamespaceResolver()
Get the external namespace resolver, if one has been set usingsetNamespaceResolver(net.sf.saxon.om.NamespaceResolver)
- Returns:
- the namespace resolver supplied by the user if set, or a system-defined namespace resolver
otherwise. By default, the
IndependentContext
object used as theXPathStaticContext
also acts as theNamespaceResolver
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setDefaultElementNamespace
public void setDefaultElementNamespace(java.lang.String uri)
Set the default namespace for elements and types- Parameters:
uri
- The namespace to be used to qualify unprefixed element names and type names appearing in the XPath expression.
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main
public static void main(java.lang.String[] args) throws java.lang.Exception
For testing only- Throws:
java.lang.Exception
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