org.dom4j

Interface XPath

All Superinterfaces:
NodeFilter

public interface XPath
extends NodeFilter

XPath represents an XPath expression after it has been parsed from a String.
Version:
$Revision: 1.20 $
Author:
James Strachan

Method Summary

boolean
booleanValueOf(Object context)
Retrieve a boolean-value interpretation of this XPath expression when evaluated against a given context.
Object
evaluate(Object context)
evaluate evaluates an XPath expression and returns the result as an Object.
FunctionContext
getFunctionContext()
DOCUMENT ME!
NamespaceContext
getNamespaceContext()
DOCUMENT ME!
String
getText()
getText will return the textual version of the XPath expression.
VariableContext
getVariableContext()
DOCUMENT ME!
boolean
matches(Node node)
matches returns true if the given node matches the XPath expression.
Number
numberValueOf(Object context)
numberValueOf evaluates an XPath expression and returns the numeric value of the XPath expression if the XPath expression results is a number, or null if the result is not a number.
List
selectNodes(Object context)
selectNodes performs this XPath expression on the given Nodeor Listof Nodes instances appending all the results together into a single list.
List
selectNodes(Object context, XPath sortXPath)
selectNodes evaluates the XPath expression on the given Nodeor Listof Nodes and returns the result as a List of Node s sorted by the sort XPath expression.
List
selectNodes(Object context, XPath sortXPath, boolean distinct)
selectNodes evaluates the XPath expression on the given Nodeor Listof Nodes and returns the result as a List of Node s sorted by the sort XPath expression.
Object
selectObject(Object context)
Deprecated. please use evaluate(Object) instead.
Node
selectSingleNode(Object context)
selectSingleNode evaluates this XPath expression on the given Nodeor Listof Nodes and returns the result as a single Node instance.
void
setFunctionContext(FunctionContext functionContext)
Sets the function context to be used when evaluating XPath expressions
void
setNamespaceContext(NamespaceContext namespaceContext)
Sets the namespace context to be used when evaluating XPath expressions
void
setNamespaceURIs(Map map)
Sets the current NamespaceContext from a Map where the keys are the String namespace prefixes and the values are the namespace URIs.
void
setVariableContext(VariableContext variableContext)
Sets the variable context to be used when evaluating XPath expressions
void
sort(List list)
sort sorts the given List of Nodes using this XPath expression as a java.util.Comparator.
void
sort(List list, boolean distinct)
sort sorts the given List of Nodes using this XPath expression as a java.util.Comparatorand optionally removing duplicates.
String
valueOf(Object context)
valueOf evaluates this XPath expression and returns the textual representation of the results using the XPath string() function.

Methods inherited from interface org.dom4j.NodeFilter

matches

Method Details

booleanValueOf

public boolean booleanValueOf(Object context)
Retrieve a boolean-value interpretation of this XPath expression when evaluated against a given context.

The boolean-value of the expression is determined per the boolean(..) core function as defined in the XPath specification. This means that an expression that selects zero nodes will return false, while an expression that selects one-or-more nodes will return true.

Parameters:
context - The node, nodeset or Context object for evaluation. This value can be null
Returns:
The boolean-value interpretation of this expression.
Since:
1.5

evaluate

public Object evaluate(Object context)
evaluate evaluates an XPath expression and returns the result as an Object. The object returned can either be a List of Nodeinstances, a Nodeinstance, a String or a Numberinstance depending on the XPath expression.
Parameters:
context - is either a node or a list of nodes on which to evalute the XPath
Returns:
the value of the XPath expression as a Listof Node instances, a Nodeinstance, a Stringor a Numberinstance depending on the XPath expression.

getFunctionContext

public FunctionContext getFunctionContext()
DOCUMENT ME!
Returns:
the current function context

getNamespaceContext

public NamespaceContext getNamespaceContext()
DOCUMENT ME!
Returns:
the current namespace context

getText

public String getText()
getText will return the textual version of the XPath expression.
Returns:
the textual format of the XPath expression.

getVariableContext

public VariableContext getVariableContext()
DOCUMENT ME!
Returns:
the current variable context

matches

public boolean matches(Node node)
matches returns true if the given node matches the XPath expression. To be more precise when evaluating this XPath expression on the given node the result set must include the node.
Specified by:
matches in interface NodeFilter
Parameters:
node - DOCUMENT ME!
Returns:
true if the given node matches this XPath expression

numberValueOf

public Number numberValueOf(Object context)
numberValueOf evaluates an XPath expression and returns the numeric value of the XPath expression if the XPath expression results is a number, or null if the result is not a number.
Parameters:
context - is either a node or a list of nodes on which to evalute the XPath
Returns:
the numeric result of the XPath expression or null if the result is not a number.

selectNodes

public List selectNodes(Object context)
selectNodes performs this XPath expression on the given Nodeor Listof Nodes instances appending all the results together into a single list.
Parameters:
context - is either a node or a list of nodes on which to evalute the XPath
Returns:
the results of all the XPath evaluations as a single list

selectNodes

public List selectNodes(Object context,
                        XPath sortXPath)
selectNodes evaluates the XPath expression on the given Nodeor Listof Nodes and returns the result as a List of Node s sorted by the sort XPath expression.
Parameters:
context - is either a node or a list of nodes on which to evalute the XPath
sortXPath - is the XPath expression to sort by
Returns:
a list of Node instances

selectNodes

public List selectNodes(Object context,
                        XPath sortXPath,
                        boolean distinct)
selectNodes evaluates the XPath expression on the given Nodeor Listof Nodes and returns the result as a List of Node s sorted by the sort XPath expression.
Parameters:
context - is either a node or a list of nodes on which to evalute the XPath
sortXPath - is the XPath expression to sort by
distinct - specifies whether or not duplicate values of the sort expression are allowed. If this parameter is true then only distinct sort expressions values are included in the result
Returns:
a list of Node instances

selectObject

public Object selectObject(Object context)

Deprecated. please use evaluate(Object) instead. WILL BE REMOVED IN dom4j-1.6 !!

Parameters:
context - is either a node or a list of nodes on which to evalute the XPath
Returns:
the value of the XPath expression as a Listof Node instances, a Nodeinstance, a Stringor a Numberinstance depending on the XPath expression.

selectSingleNode

public Node selectSingleNode(Object context)
selectSingleNode evaluates this XPath expression on the given Nodeor Listof Nodes and returns the result as a single Node instance.
Parameters:
context - is either a node or a list of nodes on which to evalute the XPath
Returns:
a single matching Node instance

setFunctionContext

public void setFunctionContext(FunctionContext functionContext)
Sets the function context to be used when evaluating XPath expressions
Parameters:
functionContext - DOCUMENT ME!

setNamespaceContext

public void setNamespaceContext(NamespaceContext namespaceContext)
Sets the namespace context to be used when evaluating XPath expressions
Parameters:
namespaceContext - DOCUMENT ME!

setNamespaceURIs

public void setNamespaceURIs(Map map)
Sets the current NamespaceContext from a Map where the keys are the String namespace prefixes and the values are the namespace URIs.

For example:

 Map uris = new HashMap();
 uris.put("SOAP-ENV", "http://schemas.xmlsoap.org/soap/envelope/");
 uris.put("m", "urn:xmethodsBabelFish");
 XPath xpath = document
         .createXPath("SOAP-ENV:Envelope/SOAP-ENV:Body/m:BabelFish");
 xpath.setNamespaceURIs(uris);
 Node babelfish = xpath.selectSingleNode(document);
 
Parameters:
map - the map containing the namespace mappings

setVariableContext

public void setVariableContext(VariableContext variableContext)
Sets the variable context to be used when evaluating XPath expressions
Parameters:
variableContext - DOCUMENT ME!

sort

public void sort(List list)
sort sorts the given List of Nodes using this XPath expression as a java.util.Comparator.
Parameters:
list - is the list of Nodes to sort

sort

public void sort(List list,
                 boolean distinct)
sort sorts the given List of Nodes using this XPath expression as a java.util.Comparatorand optionally removing duplicates.
Parameters:
list - is the list of Nodes to sort
distinct - if true then duplicate values (using the sortXPath for comparisions) will be removed from the List

valueOf

public String valueOf(Object context)
valueOf evaluates this XPath expression and returns the textual representation of the results using the XPath string() function.
Parameters:
context - is either a node or a list of nodes on which to evalute the XPath
Returns:
the string representation of the results of the XPath expression

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