Interface Node
- All Superinterfaces:
Cloneable
- All Known Subinterfaces:
Attribute
,Branch
,CDATA
,CharacterData
,Comment
,Document
,DocumentType
,Element
,Entity
,ProcessingInstruction
,Text
- All Known Implementing Classes:
AbstractAttribute
,AbstractBranch
,AbstractCDATA
,AbstractCharacterData
,AbstractComment
,AbstractDocument
,AbstractDocumentType
,AbstractElement
,AbstractEntity
,AbstractNode
,AbstractProcessingInstruction
,AbstractText
,BaseElement
,BeanAttribute
,BeanElement
,DefaultAttribute
,DefaultCDATA
,DefaultComment
,DefaultDocument
,DefaultDocumentType
,DefaultElement
,DefaultEntity
,DefaultNamespace
,DefaultProcessingInstruction
,DefaultText
,DOMAttribute
,DOMCDATA
,DOMComment
,DOMDocument
,DOMDocumentType
,DOMElement
,DOMEntityReference
,DOMNamespace
,DOMProcessingInstruction
,DOMText
,FlyweightAttribute
,FlyweightCDATA
,FlyweightComment
,FlyweightEntity
,FlyweightProcessingInstruction
,FlyweightText
,IndexedElement
,Namespace
,NonLazyElement
,UserDataAttribute
,UserDataElement
Node
defines the polymorphic behavior for all XML nodes in a
dom4j tree.
A node can be output as its XML format, can be detached from its position in a document and can have XPath expressions evaluated on itself.
A node may optionally support the parent relationship and may be read only.
- Version:
- $Revision: 1.31 $
- Author:
- James Strachan
- See Also:
-
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final short
Matches Element nodesstatic final short
Matches elements nodesstatic final short
Matches elements nodesstatic final short
Matches Comments nodesstatic final short
Matches Document nodesstatic final short
Matches DocumentType nodesstatic final short
Matches Element nodesstatic final short
Matches elements nodesstatic final short
The maximum number of node types for sizing purposesstatic final short
Matchs a Namespace Node - NOTE this differs from DOMstatic final short
Matches ProcessingInstructionstatic final short
Matches elements nodesstatic final short
Does not match any valid node -
Method Summary
Modifier and TypeMethodDescriptionvoid
accept
is the method used in the Visitor Pattern.asXML()
asXML
returns the textual XML representation of this node.asXPathResult
(Element parent) asXPathResult
returns a version of this node which is capable of being an XPath result.clone()
clone
will return a deep clone or if this node is read-only then clone will return the same instance.createXPath
(String xpathExpression) createXPath
creates an XPath object for the given xpathExpression.detach()
Removes this node from its parent if there is one.getDocument
returns theDocument
that thisNode
is part of if this node supports the parent relationship.getName()
getName
returns the name of this node.short
Returns the code according to the type of node.DOCUMENT ME!getParent
returns the parentElement
if this node supports the parent relationship or null if it is the root element or does not support the parent relationship.getPath()
Returns the XPath expression which will return a node set containing the given node such as /a/b/@c.Returns the relative XPath expression which will return a node set containing the given node such as a/b/@c.Returns the XPath string-value of this node.getText()
Returns the text of this node.Returns the XPath expression which will return a nodeset of one node which is the current node.getUniquePath
(Element context) Returns the relative unique XPath expression from the given context which will return a nodeset of one node which is the current node.boolean
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
returns true if this node is read only and cannot be modified.boolean
matches
returns true if evaluating the given XPath expression on this node returns a non-empty node set containing this node.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.selectNodes
(String xpathExpression) selectNodes
evaluates an XPath expression and returns the result as aList
ofNode
instances orString
instances depending on the XPath expression.selectNodes
(String xpathExpression, String comparisonXPathExpression) selectNodes
evaluates an XPath expression then sorts the results using a secondary XPath expression Returns a sortedList
ofNode
instances.selectNodes
(String xpathExpression, String comparisonXPathExpression, boolean removeDuplicates) selectNodes
evaluates an XPath expression then sorts the results using a secondary XPath expression Returns a sortedList
ofNode
instances.selectObject
(String xpathExpression) selectObject
evaluates an XPath expression and returns the result as anObject
.selectSingleNode
(String xpathExpression) selectSingleNode
evaluates an XPath expression and returns the result as a singleNode
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
Sets the text data of this node or this method will throw anUnsupportedOperationException
if it is read-only.void
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
Sets the text data of this node or this method will throw anUnsupportedOperationException
if it is read-only.boolean
supportsParent
returns true if this node supports the parent relationship.valueOf
evaluates an XPath expression and returns the textual representation of the results the XPath string-value of this node.void
write
writes this node as the default XML notation for this node.
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Field Details
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ANY_NODE
static final short ANY_NODEMatches Element nodes- See Also:
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ELEMENT_NODE
static final short ELEMENT_NODEMatches Element nodes- See Also:
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ATTRIBUTE_NODE
static final short ATTRIBUTE_NODEMatches elements nodes- See Also:
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TEXT_NODE
static final short TEXT_NODEMatches elements nodes- See Also:
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CDATA_SECTION_NODE
static final short CDATA_SECTION_NODEMatches elements nodes- See Also:
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ENTITY_REFERENCE_NODE
static final short ENTITY_REFERENCE_NODEMatches elements nodes- See Also:
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PROCESSING_INSTRUCTION_NODE
static final short PROCESSING_INSTRUCTION_NODEMatches ProcessingInstruction- See Also:
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COMMENT_NODE
static final short COMMENT_NODEMatches Comments nodes- See Also:
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DOCUMENT_NODE
static final short DOCUMENT_NODEMatches Document nodes- See Also:
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DOCUMENT_TYPE_NODE
static final short DOCUMENT_TYPE_NODEMatches DocumentType nodes- See Also:
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NAMESPACE_NODE
static final short NAMESPACE_NODEMatchs a Namespace Node - NOTE this differs from DOM- See Also:
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UNKNOWN_NODE
static final short UNKNOWN_NODEDoes not match any valid node- See Also:
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MAX_NODE_TYPE
static final short MAX_NODE_TYPEThe maximum number of node types for sizing purposes- See Also:
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Method Details
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supportsParent
boolean supportsParent()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.
- Returns:
- true if this node supports the parent relationship or false it is not supported
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getParent
Element getParent()getParent
returns the parentElement
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.- Returns:
- the parent of this node or null if it is the root of the tree or the parent relationship is not supported.
-
setParent
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.- Parameters:
parent
- is the new parent of this node.
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getDocument
Document getDocument()getDocument
returns theDocument
that thisNode
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.- Returns:
- the document of this node or null if this feature is not
supported or the node is not associated with a
Document
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setDocument
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.- Parameters:
document
- is the new document of this node.
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isReadOnly
boolean isReadOnly()isReadOnly
returns true if this node is read only and cannot be modified. Any attempt to modify a read-onlyNode
will result in anUnsupportedOperationException
being thrown.- Returns:
- true if this
Node
is read only and cannot be modified otherwise false.
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hasContent
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.- Returns:
- true if this
Node
is a Branch with a nodeCount() of one or more.
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getName
String getName()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.- Returns:
- the XML name of this node
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setName
Sets the text data of this node or this method will throw an
UnsupportedOperationException
if it is read-only.- Parameters:
name
- is the new name of this node
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getText
String getText()Returns the text of this node.
- Returns:
- the text for this node.
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setText
Sets the text data of this node or this method will throw an
UnsupportedOperationException
if it is read-only.- Parameters:
text
- is the new textual value of this node
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getStringValue
String getStringValue()Returns the XPath string-value of this node. The behaviour of this method is defined in the XPath specification .- Returns:
- the text from all the child Text and Element nodes appended together.
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getPath
String getPath()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.
- Returns:
- the XPath expression which will return a nodeset containing at least this node.
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getPath
Returns the relative 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.- Parameters:
context
- is the parent context from which the relative path should start. If the context is null or the context is not an ancestor of this node then the path will be absolute and start from the document and so begin with the '/' character.- Returns:
- the XPath expression relative to the given context which will return a nodeset containing at least this node.
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getUniquePath
String getUniquePath()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.
- Returns:
- the XPath expression which will return a nodeset containing just this node.
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getUniquePath
Returns the relative unique XPath expression from the given context 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.
- Parameters:
context
- is the parent context from which the path should start. If the context is null or the context is not an ancestor of this node then the path will start from the document and so begin with the '/' character.- Returns:
- the XPath expression relative to the given context which will return a nodeset containing just this node.
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asXML
String asXML()asXML
returns the textual XML representation of this node.- Returns:
- the XML representation of this node
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write
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 useXMLWriter
or its derivations.- Parameters:
writer
- is theWriter
to output the XML to- Throws:
IOException
- DOCUMENT ME!
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getNodeType
short getNodeType()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.- Returns:
- a W3C DOM complient code for the node type such as ELEMENT_NODE or ATTRIBUTE_NODE
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getNodeTypeName
String getNodeTypeName()DOCUMENT ME!- Returns:
- the name of the type of node such as "Document", "Element", "Attribute" or "Text"
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detach
Node detach()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() );
- Returns:
- the node that has been removed from its parent node if any and its document if any.
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selectNodes
selectNodes
evaluates an XPath expression and returns the result as aList
ofNode
instances orString
instances depending on the XPath expression.- Parameters:
xpathExpression
- is the XPath expression to be evaluated- Returns:
- the list of
Node
orString
instances depending on the XPath expression
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selectObject
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selectNodes
selectNodes
evaluates an XPath expression then sorts the results using a secondary XPath expression Returns a sortedList
ofNode
instances.- Parameters:
xpathExpression
- is the XPath expression to be evaluatedcomparisonXPathExpression
- is the XPath expression used to compare the results by for sorting- Returns:
- the list of
Node
instances sorted by the comparisonXPathExpression
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selectNodes
List selectNodes(String xpathExpression, String comparisonXPathExpression, boolean removeDuplicates) selectNodes
evaluates an XPath expression then sorts the results using a secondary XPath expression Returns a sortedList
ofNode
instances.- Parameters:
xpathExpression
- is the XPath expression to be evaluatedcomparisonXPathExpression
- is the XPath expression used to compare the results by for sortingremoveDuplicates
- 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
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selectSingleNode
selectSingleNode
evaluates an XPath expression and returns the result as a singleNode
instance.- Parameters:
xpathExpression
- is the XPath expression to be evaluated- Returns:
- the
Node
matching the XPath expression
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valueOf
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 .- Parameters:
xpathExpression
- is the XPath expression to be evaluated- Returns:
- the string-value representation of the results of the XPath expression
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numberValueOf
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.- 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.
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matches
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 )
- Parameters:
xpathExpression
- is an XPath expression- Returns:
- true if this node is returned by the given XPath expression
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createXPath
createXPath
creates an XPath object for the given xpathExpression. The XPath object allows the variable context to be specified.- Parameters:
xpathExpression
- is the XPath expression to be evaluated- Returns:
- an XPath object represeting the given expression
- Throws:
InvalidXPathException
- if the XPath expression is invalid
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asXPathResult
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.- Parameters:
parent
- DOCUMENT ME!- Returns:
- a
Node
which supports the parent relationship
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accept
accept
is the method used in the Visitor Pattern.- Parameters:
visitor
- is the visitor in the Visitor Pattern
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clone
Object clone()clone
will return a deep clone or if this node is read-only then clone will return the same instance.- Returns:
- a deep clone of myself or myself if I am read only.
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