Class AbstractNode

java.lang.Object

org.dom4j.tree.AbstractNode

All Implemented Interfaces:

Serializable, Cloneable, Node

Direct Known Subclasses:

AbstractAttribute, AbstractBranch, AbstractCharacterData, AbstractDocumentType, AbstractEntity, AbstractProcessingInstruction, Namespace

public abstract class AbstractNode
extends Object
implements Node, Cloneable, Serializable

AbstractNode is an abstract base class for tree implementors to use for implementation inheritence.

Version:

$Revision: 1.31 $

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
private static final DocumentFactory	DOCUMENT_FACTORY	The DocumentFactory instance used by default
protected static final String[]	NODE_TYPE_NAMES

Fields inherited from interface Node

ANY_NODE, ATTRIBUTE_NODE, CDATA_SECTION_NODE, COMMENT_NODE, DOCUMENT_NODE, DOCUMENT_TYPE_NODE, ELEMENT_NODE, ENTITY_REFERENCE_NODE, MAX_NODE_TYPE, NAMESPACE_NODE, PROCESSING_INSTRUCTION_NODE, TEXT_NODE, UNKNOWN_NODE

Constructor Summary

Constructors

Constructor	Description
AbstractNode()

Method Summary

Modifier and Type	Method	Description
Node	asXPathResult(Element parent)	asXPathResult returns a version of this node which is capable of being an XPath result.
Object	clone()	clone will return a deep clone or if this node is read-only then clone will return the same instance.
Pattern	createPattern(String patternText)
XPath	createXPath(String xpathExpression)	createXPath creates an XPath object for the given xpathExpression.
NodeFilter	createXPathFilter(String patternText)
protected Node	createXPathResult(Element parent)
Node	detach()	Removes this node from its parent if there is one.
Document	getDocument()	getDocument returns the Document that this Node is part of if this node supports the parent relationship.
protected DocumentFactory	getDocumentFactory()
String	getName()	getName returns the name of this node.
short	getNodeType()	Returns the code according to the type of node.
String	getNodeTypeName()	DOCUMENT ME!
Element	getParent()	getParent returns the parent Element if this node supports the parent relationship or null if it is the root element or does not support the parent relationship.
String	getPath()	Returns the XPath expression which will return a node set containing the given node such as /a/b/@c.
String	getStringValue()	Returns the XPath string-value of this node.
String	getText()	Returns the text of this node.
String	getUniquePath()	Returns the XPath expression which will return a nodeset of one node which is the current node.
boolean	hasContent()	hasContent returns true if this node is a Branch (either an Element or a Document) and it contains at least one content node such as a child Element or Text node.
boolean	isReadOnly()	isReadOnly returns true if this node is read only and cannot be modified.
boolean	matches(String patternText)	matches returns true if evaluating the given XPath expression on this node returns a non-empty node set containing this node.
Number	numberValueOf(String xpathExpression)	numberValueOf evaluates an XPath expression and returns the numeric value of the XPath expression if the XPath expression results in a number, or null if the result is not a number.
List<Node>	selectNodes(String xpathExpression)	selectNodes evaluates an XPath expression and returns the result as a List of Node instances or String instances depending on the XPath expression.
List<Node>	selectNodes(String xpathExpression, String comparisonXPathExpression)	selectNodes evaluates an XPath expression then sorts the results using a secondary XPath expression Returns a sorted List of Node instances.
List<Node>	selectNodes(String xpathExpression, String comparisonXPathExpression, boolean removeDuplicates)	selectNodes evaluates an XPath expression then sorts the results using a secondary XPath expression Returns a sorted List of Node instances.
Object	selectObject(String xpathExpression)	selectObject evaluates an XPath expression and returns the result as an Object.
Node	selectSingleNode(String xpathExpression)	selectSingleNode evaluates an XPath expression and returns the result as a single Node instance.
void	setDocument(Document document)	setDocument sets the document of this node if the parent relationship is supported or does nothing if the parent relationship is not supported.
void	setName(String name)	Sets the text data of this node or this method will throw an UnsupportedOperationException if it is read-only.
void	setParent(Element parent)	setParent sets the parent relationship of this node if the parent relationship is supported or does nothing if the parent relationship is not supported.
void	setText(String text)	Sets the text data of this node or this method will throw an UnsupportedOperationException if it is read-only.
boolean	supportsParent()	supportsParent returns true if this node supports the parent relationship.
String	valueOf(String xpathExpression)	valueOf evaluates an XPath expression and returns the textual representation of the results the XPath string-value of this node.
void	write(Writer writer)	write writes this node as the default XML notation for this node.

Methods inherited from class Object

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

Methods inherited from interface Node

accept, asXML, getPath, getUniquePath

Field Details

NODE_TYPE_NAMES

protected static final String[] NODE_TYPE_NAMES

DOCUMENT_FACTORY

private static final DocumentFactory DOCUMENT_FACTORY

The DocumentFactory instance used by default

Constructor Details

AbstractNode

public AbstractNode()

Method Details

getNodeType

public short getNodeType()

Description copied from interface: Node

Returns the code according to the type of node. This makes processing nodes polymorphically much easier as the switch statement can be used instead of multiple if (instanceof) statements.

Specified by:

getNodeType in interface Node

Returns:

a W3C DOM complient code for the node type such as ELEMENT_NODE or ATTRIBUTE_NODE

getNodeTypeName

public String getNodeTypeName()

Description copied from interface: Node

DOCUMENT ME!

Specified by:

getNodeTypeName in interface Node

Returns:

the name of the type of node such as "Document", "Element", "Attribute" or "Text"

getDocument

public Document getDocument()

Description copied from interface: Node

getDocument returns the Document that this Node is part of if this node supports the parent relationship.

This method is an optional feature and may not be supported for all Node implementations.

Specified by:

getDocument in interface Node

Returns:

the document of this node or null if this feature is not supported or the node is not associated with a Document

setDocument

public void setDocument(Document document)

Description copied from interface: Node

setDocument sets the document of this node if the parent relationship is supported or does nothing if the parent relationship is not supported.

This method should only be called from inside a Document implementation method and is not intended for general use.

Specified by:

setDocument in interface Node

Parameters:

document - is the new document of this node.

getParent

public Element getParent()

Description copied from interface: Node

getParent returns the parent Element if this node supports the parent relationship or null if it is the root element or does not support the parent relationship.

This method is an optional feature and may not be supported for all Node implementations.

Specified by:

getParent in interface Node

Returns:

the parent of this node or null if it is the root of the tree or the parent relationship is not supported.

setParent

public void setParent(Element parent)

Description copied from interface: Node

setParent sets the parent relationship of this node if the parent relationship is supported or does nothing if the parent relationship is not supported.

This method should only be called from inside an Element implementation method and is not intended for general use.

Specified by:

setParent in interface Node

Parameters:

parent - is the new parent of this node.

supportsParent

public boolean supportsParent()

Description copied from interface: Node

supportsParent returns true if this node supports the parent relationship.

Some XML tree implementations are singly linked and only support downward navigation through children relationships. The default case is that both parent and children relationships are supported though for memory and performance reasons the parent relationship may not be supported.

Specified by:

supportsParent in interface Node

Returns:

true if this node supports the parent relationship or false it is not supported

isReadOnly

public boolean isReadOnly()

Description copied from interface: Node

isReadOnly returns true if this node is read only and cannot be modified. Any attempt to modify a read-only Node will result in an UnsupportedOperationException being thrown.

Specified by:

isReadOnly in interface Node

Returns:

true if this Node is read only and cannot be modified otherwise false.

hasContent

public boolean hasContent()

Description copied from interface: Node

hasContent returns true if this node is a Branch (either an Element or a Document) and it contains at least one content node such as a child Element or Text node.

Specified by:

hasContent in interface Node

Returns:

true if this Node is a Branch with a nodeCount() of one or more.

getPath

public String getPath()

Description copied from interface: Node

Returns the XPath expression which will return a node set containing the given node such as /a/b/@c. No indexing will be used to restrict the path if multiple elements with the same name occur on the path.

Specified by:

getPath in interface Node

Returns:

the XPath expression which will return a nodeset containing at least this node.

getUniquePath

public String getUniquePath()

Description copied from interface: Node

Returns the XPath expression which will return a nodeset of one node which is the current node. This method will use the XPath index operator to restrict the path if multiple elements with the same name occur on the path.

Specified by:

getUniquePath in interface Node

Returns:

the XPath expression which will return a nodeset containing just this node.

clone

public Object clone()

Description copied from interface: Node

clone will return a deep clone or if this node is read-only then clone will return the same instance.

Specified by:

clone in interface Node

Overrides:

clone in class Object

Returns:

a deep clone of myself or myself if I am read only.

detach

public Node detach()

Description copied from interface: Node

Removes this node from its parent if there is one. If this node is the root element of a document then it is removed from the document as well.

This method is useful if you want to remove a node from its source document and add it to another document. For example

Node node = ...; Element someOtherElement = ...; someOtherElement.add( node.detach() );

Specified by:

detach in interface Node

Returns:

the node that has been removed from its parent node if any and its document if any.

getName

public String getName()

Description copied from interface: Node

getName returns the name of this node. This is the XML local name of the element, attribute, entity or processing instruction. For CDATA and Text nodes this method will return null.

Specified by:

getName in interface Node

Returns:

the XML name of this node

setName

public void setName(String name)

Description copied from interface: Node

Sets the text data of this node or this method will throw an UnsupportedOperationException if it is read-only.

Specified by:

setName in interface Node

Parameters:

name - is the new name of this node

getText

public String getText()

Description copied from interface: Node

Returns the text of this node.

Specified by:

getText in interface Node

Returns:

the text for this node.

getStringValue

public String getStringValue()

Description copied from interface: Node

Returns the XPath string-value of this node. The behaviour of this method is defined in the XPath specification .

Specified by:

getStringValue in interface Node

Returns:

the text from all the child Text and Element nodes appended together.

setText

public void setText(String text)

Description copied from interface: Node

Sets the text data of this node or this method will throw an UnsupportedOperationException if it is read-only.

Specified by:

setText in interface Node

Parameters:

text - is the new textual value of this node

write

public void write(Writer writer)
           throws IOException

Description copied from interface: Node

write writes this node as the default XML notation for this node. If you wish to control the XML output (such as for pretty printing, changing the indentation policy etc.) then please use XMLWriter or its derivations.

Specified by:

write in interface Node

Parameters:

writer - is the Writer to output the XML to

Throws:

IOException - DOCUMENT ME!

selectObject

public Object selectObject(String xpathExpression)

Description copied from interface: Node

selectObject evaluates an XPath expression and returns the result as an Object. The object returned can either be a List of one or more Nodeinstances or a scalar object like a Stringor a Numberinstance depending on the XPath expression.

Specified by:

selectObject in interface Node

Parameters:

xpathExpression - is the XPath expression to be evaluated

Returns:

the value of the XPath expression as a Listof Node instances, a Stringor a Numberinstance depending on the XPath expression.

selectNodes

public List<Node> selectNodes(String xpathExpression)

Description copied from interface: Node

selectNodes evaluates an XPath expression and returns the result as a List of Node instances or String instances depending on the XPath expression.

Specified by:

selectNodes in interface Node

Parameters:

xpathExpression - is the XPath expression to be evaluated

Returns:

the list of Node or String instances depending on the XPath expression

selectNodes

public List<Node> selectNodes(String xpathExpression,
 String comparisonXPathExpression)

Description copied from interface: Node

selectNodes evaluates an XPath expression then sorts the results using a secondary XPath expression Returns a sorted List of Node instances.

Specified by:

selectNodes in interface Node

Parameters:

xpathExpression - is the XPath expression to be evaluated

comparisonXPathExpression - is the XPath expression used to compare the results by for sorting

Returns:

the list of Node instances sorted by the comparisonXPathExpression

selectNodes

public List<Node> selectNodes(String xpathExpression,
 String comparisonXPathExpression,
 boolean removeDuplicates)

Description copied from interface: Node

selectNodes evaluates an XPath expression then sorts the results using a secondary XPath expression Returns a sorted List of Node instances.

Specified by:

selectNodes in interface Node

Parameters:

xpathExpression - is the XPath expression to be evaluated

comparisonXPathExpression - is the XPath expression used to compare the results by for sorting

removeDuplicates - if this parameter is true then duplicate values (using the comparisonXPathExpression) are removed from the result List.

Returns:

the list of Node instances sorted by the comparisonXPathExpression

selectSingleNode

public Node selectSingleNode(String xpathExpression)

Description copied from interface: Node

selectSingleNode evaluates an XPath expression and returns the result as a single Node instance.

Specified by:

selectSingleNode in interface Node

Parameters:

xpathExpression - is the XPath expression to be evaluated

Returns:

the Node matching the XPath expression

valueOf

public String valueOf(String xpathExpression)

Description copied from interface: Node

valueOf evaluates an XPath expression and returns the textual representation of the results the XPath string-value of this node. The string-value for a given node type is defined in the XPath specification .

Specified by:

valueOf in interface Node

Parameters:

xpathExpression - is the XPath expression to be evaluated

Returns:

the string-value representation of the results of the XPath expression

numberValueOf

public Number numberValueOf(String xpathExpression)

Description copied from interface: Node

numberValueOf evaluates an XPath expression and returns the numeric value of the XPath expression if the XPath expression results in a number, or null if the result is not a number.

Specified by:

numberValueOf in interface Node

Parameters:

xpathExpression - is the XPath expression to be evaluated

Returns:

the numeric result of the XPath expression or null if the result is not a number.

matches

public boolean matches(String patternText)

Description copied from interface: Node

matches returns true if evaluating the given XPath expression on this node returns a non-empty node set containing this node.

This method does not behave like the <xsl:if> element - if you want that behaviour, to evaluate if an XPath expression matches something, then you can use the following code to be equivalent...

if ( node.selectSingleNode( "/some/path" ) != nulll )

Specified by:

matches in interface Node

Parameters:

patternText - is an XPath expression

Returns:

true if this node is returned by the given XPath expression

createXPath

public XPath createXPath(String xpathExpression)

Description copied from interface: Node

createXPath creates an XPath object for the given xpathExpression. The XPath object allows the variable context to be specified.

Specified by:

createXPath in interface Node

Parameters:

xpathExpression - is the XPath expression to be evaluated

Returns:

an XPath object represeting the given expression

createXPathFilter

public NodeFilter createXPathFilter(String patternText)

createPattern

public Pattern createPattern(String patternText)

asXPathResult

public Node asXPathResult(Element parent)

Description copied from interface: Node

asXPathResult returns a version of this node which is capable of being an XPath result. The result of an XPath expression should always support the parent relationship, whether the original XML tree was singly or doubly linked. If the node does not support the parent relationship then a new node will be created which is linked to its parent and returned.

Specified by:

asXPathResult in interface Node

Parameters:

parent - DOCUMENT ME!

Returns:

a Node which supports the parent relationship

getDocumentFactory

protected DocumentFactory getDocumentFactory()

createXPathResult

protected Node createXPathResult(Element parent)