| java.lang.Object
 net.sf.saxon.xpath.XPathEvaluator
| XPathEvaluator | | public class XPathEvaluator implements XPath(Code) | | XPathEvaluator provides a simple API for standalone XPath processing (that is,
executing XPath expressions in the absence of an XSLT stylesheet). It is an implementation
of the JAXP 1.3 XPath interface, with additional methods provided (a) for backwards
compatibility (b) to give extra control over the XPath evaluation, and (c) to support
XPath 2.0.
author:
Michael H. Kay |
| Constructor Summary | |
| public | XPathEvaluator()
Default constructor. | | public | XPathEvaluator(Configuration config)
Construct an XPathEvaluator with a specified configuration.
Parameters:
config - the configuration to be used. | | public | XPathEvaluator(Source source)
Construct an XPathEvaluator to process a particular source document. |
| Method Summary | |
| public XPathExpression | compile(String expr)
| | public XPathExpressionImpl | createExpression(String expression)
Prepare an XPath expression for subsequent evaluation.
Parameters:
expression - The XPath expression to be evaluated, supplied as a string. | | public List | evaluate(String expression)
Prepare and execute an XPath expression, supplied as a string, and returning the results
as a List.
Parameters:
expression - The XPath expression to be evaluated, supplied as a string. | | public Object | evaluate(String expr, Object node, QName qName)
Single-shot method to compile and execute an XPath 2.0 expression.
Parameters:
expr - The XPath 2.0 expression to be compiled and executed
Parameters:
node - The context node for evaluation of the expression
Parameters:
qName - The type of result required. | | public String | evaluate(String expr, Object node)
Single-shot method to compile an execute an XPath 2.0 expression, returning
the result as a string. | | public Object | evaluate(String expr, InputSource inputSource, QName qName)
Single-shot method to parse and build a source document, and
compile an execute an XPath 2.0 expression, against that document
Parameters:
expr - The XPath 2.0 expression to be compiled and executed
Parameters:
inputSource - The source document: this will be parsed and built into a tree,and the XPath expression will be executed with the root node of the tree as thecontext node
Parameters:
qName - The type of result required. | | public String | evaluate(String expr, InputSource inputSource)
| | public Object | evaluateSingle(String expression)
Prepare and execute an XPath expression, supplied as a string, and returning the first
item in the result. | | public NamespaceContext | getNamespaceContext()
| | public StandaloneContext | getStaticContext()
| | public XPathFunctionResolver | getXPathFunctionResolver()
| | public XPathVariableResolver | getXPathVariableResolver()
| | public void | importSchema(Source source)
Import a schema. | | public boolean | isBackwardsCompatible()
| | public static void | main(String[] args)
A simple command-line interface for the XPathEvaluator (not documented). | | public void | reset()
| | public void | setBackwardsCompatible(boolean compatible)
| | public void | setContextNode(NodeInfo node)
Set the context node. | | public void | setNamespaceContext(NamespaceContext namespaceContext)
Set the namespace context to be used. | | public NodeInfo | setSource(Source source)
Supply the document against which XPath expressions are to be executed. | | public void | setStaticContext(StandaloneContext context)
Set the static context for compiling XPath expressions. | | public void | setStripSpace(boolean strip)
Indicate whether all whitespace text nodes in the source document are to be
removed. | | public void | setXPathFunctionResolver(XPathFunctionResolver xPathFunctionResolver)
| | public void | setXPathVariableResolver(XPathVariableResolver xPathVariableResolver)
|
| XPathEvaluator | | public XPathEvaluator()(Code) | | Default constructor. Creates an XPathEvaluator with a default configuration and name pool.
The default Configuration is not schema-aware.
|
| XPathEvaluator | | public XPathEvaluator(Configuration config)(Code) | | Construct an XPathEvaluator with a specified configuration.
Parameters:
config - the configuration to be used. If schema-aware XPath expressions are to be used,this must be a SchemaAwareConfiguration. |
| XPathEvaluator | | public XPathEvaluator(Source source) throws net.sf.saxon.trans.XPathException(Code) | | Construct an XPathEvaluator to process a particular source document. This is equivalent to
using the default constructor and immediately calling setSource().
Parameters:
source - The source document (or a specific node within it). |
| compile | | public XPathExpression compile(String expr) throws XPathExpressionException(Code) | | Compile an XPath 2.0 expression
Parameters:
expr - the XPath 2.0 expression to be compiled, as a string the compiled form of the expression
throws:
XPathExpressionException - if there are any static errors in the expression.Note that references to undeclared variables are not treated as static errors, becausevariables are not pre-declared using this API. |
| createExpression | | public XPathExpressionImpl createExpression(String expression) throws net.sf.saxon.trans.XPathException(Code) | | Prepare an XPath expression for subsequent evaluation.
Parameters:
expression - The XPath expression to be evaluated, supplied as a string. an XPathExpression object representing the prepared expression
throws:
net.sf.saxon.trans.XPathException - if the syntax of the expression is wrong, or if it references namespaces,variables, or functions that have not been declared. |
| evaluate | | public List evaluate(String expression) throws net.sf.saxon.trans.XPathException(Code) | | Prepare and execute an XPath expression, supplied as a string, and returning the results
as a List.
Parameters:
expression - The XPath expression to be evaluated, supplied as a string. The results of the expression, as a List. The List represents the sequenceof items returned by the expression. Each item in the list will either be an objectrepresenting a node, or a Java object representing an atomic value.The types of Java object that may be included in the list, and the XML Schema data types that theycorrespond to, are as follows:- Boolean (xs:boolean)
- String (xs:string)
- BigDecimal (xs:decimal)
- Long (xs:integer and its derived types)
- Double (xs:double)
- Float (xs:float)
- Date (xs:date, xs:dateTime)
|
| evaluate | | public String evaluate(String expr, Object node) throws XPathExpressionException(Code) | | Single-shot method to compile an execute an XPath 2.0 expression, returning
the result as a string.
Parameters:
expr - The XPath 2.0 expression to be compiled and executed
Parameters:
node - The context node for evaluation of the expression the result of evaluating the expression, converted to a string as ifby calling the XPath string() function
throws:
XPathExpressionException - if any static or dynamic error occursin evaluating the expression. |
| evaluate | | public String evaluate(String expr, InputSource inputSource) throws XPathExpressionException(Code) | | Single-shot method to parse and build a source document, and
compile an execute an XPath 2.0 expression, against that document,
returning the result as a string
Parameters:
expr - The XPath 2.0 expression to be compiled and executed
Parameters:
inputSource - The source document: this will be parsed and built into a tree,and the XPath expression will be executed with the root node of the tree as thecontext node the result of evaluating the expression, converted to a string asif by calling the XPath string() function
throws:
XPathExpressionException - if any static or dynamic error occursin evaluating the expression. |
| evaluateSingle | | public Object evaluateSingle(String expression) throws net.sf.saxon.trans.XPathException(Code) | | Prepare and execute an XPath expression, supplied as a string, and returning the first
item in the result. This is useful where it is known that the expression will only return
a singleton value (for example, a single node, or a boolean).
Parameters:
expression - The XPath expression to be evaluated, supplied as a string. The first item in the sequence returned by the expression. If the expressionreturns an empty sequence, this method returns null. Otherwise, it returns the firstitem in the result sequence, represented as a Java object using the same mapping as forthe evaluate() method |
| getXPathFunctionResolver | | public XPathFunctionResolver getXPathFunctionResolver()(Code) | | Get the resolver for XPath functions
the resolver, if one has been set |
| getXPathVariableResolver | | public XPathVariableResolver getXPathVariableResolver()(Code) | | Get the resolver for XPath variables
the resolver, if one has been set |
| importSchema | | public void importSchema(Source source) throws SchemaException(Code) | | Import a schema. This is possible only if the schema-aware version of Saxon is being used,
and if the Configuration is a SchemaAwareConfiguration. Having imported a schema, the types
defined in that schema become part of the static context.
Parameters:
source - A Source object identifying the schema document to be loaded
throws:
net.sf.saxon.type.SchemaException - if the schema contained in this document is invalid
throws:
UnsupportedOperationException - if the configuration is not schema-aware |
| isBackwardsCompatible | | public boolean isBackwardsCompatible()(Code) | | Get the value of XPath 1.0 compatibility mode
true if XPath 1.0 compatibility mode is set |
| main | | public static void main(String[] args) throws Exception(Code) | | A simple command-line interface for the XPathEvaluator (not documented).
First parameter is the filename containing the source document, second
parameter is the XPath expression.
|
| reset | | public void reset()(Code) | | |
| setBackwardsCompatible | | public void setBackwardsCompatible(boolean compatible)(Code) | | Set XPath 1.0 compatibility mode on or off (by default, it is false)
Parameters:
compatible - true if XPath 1.0 compatibility mode is to be set to true, falseif it is to be set to false. |
| setContextNode | | public void setContextNode(NodeInfo node)(Code) | | Set the context node. This provides the context node for any expressions executed after this
method is called, including expressions that were prepared before it was called.
Parameters:
node - The node to be used as the context node. This mustbe a node within the context document (the document supplied using the setSource() method).
throws:
NullPointerException - if the argument is null
throws:
IllegalArgumentException - if the supplied node is not a node in the context document |
| setNamespaceContext | | public void setNamespaceContext(NamespaceContext namespaceContext)(Code) | | Set the namespace context to be used. This supplements any namespaces declared directly
using declareNamespace on the staticContext object
Parameters:
namespaceContext - The namespace context |
| setSource | | public NodeInfo setSource(Source source) throws net.sf.saxon.trans.XPathException(Code) | | Supply the document against which XPath expressions are to be executed. This
method must be called before preparing or executing an XPath expression.
Setting a new source document clears all the namespaces that have been declared.
Parameters:
source - Any javax.xml.transform.Source object representing the document againstwhich XPath expressions will be executed. Note that a Saxon net.sf.saxon.om.DocumentInfo DocumentInfo(indeed any net.sf.saxon.om.NodeInfo NodeInfo)can be used as a Source. To use a third-party DOM Document as a source, create an instance ofjavax.xml.transform.dom.DOMSource DOMSource to wrap it.The Source object supplied also determines the initial settingof the context item. In most cases the context node will be the root of the supplied document;however, if a NodeInfo or DOMSource is supplied it can be any node in the document. the NodeInfo of the start node in the resulting document object. |
| setStaticContext | | public void setStaticContext(StandaloneContext context)(Code) | | Set the static context for compiling XPath expressions. This provides 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 the StandaloneContext 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.
|
| setStripSpace | | public void setStripSpace(boolean strip)(Code) | | Indicate whether all whitespace text nodes in the source document are to be
removed. This option has no effect unless it is called before the call on setSource(),
and unless the Source supplied to setSource() is a SAXSource or StreamSource.
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. |
| setXPathFunctionResolver | | public void setXPathFunctionResolver(XPathFunctionResolver xPathFunctionResolver)(Code) | | Set the resolver for XPath functions
Parameters:
xPathFunctionResolver - |
| setXPathVariableResolver | | public void setXPathVariableResolver(XPathVariableResolver xPathVariableResolver)(Code) | | Set the resolver for XPath variables
Parameters:
xPathVariableResolver - |
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