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Summary: Nested | Field | Method | Constr | Detail: Nested | Field | Method | Constr |
public interface Node
extends Cloneable
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.
supportsParent()
, isReadOnly()
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String |
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Node |
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Object |
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XPath |
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Node |
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Document |
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Element |
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public static final short ANY_NODE
Matches Element nodes
- Field Value:
- 0
public static final short ATTRIBUTE_NODE
Matches elements nodes
- Field Value:
- 2
public static final short CDATA_SECTION_NODE
Matches elements nodes
- Field Value:
- 4
public static final short COMMENT_NODE
Matches Comments nodes
- Field Value:
- 8
public static final short DOCUMENT_NODE
Matches Document nodes
- Field Value:
- 9
public static final short DOCUMENT_TYPE_NODE
Matches DocumentType nodes
- Field Value:
- 10
public static final short ELEMENT_NODE
Matches Element nodes
- Field Value:
- 1
public static final short ENTITY_REFERENCE_NODE
Matches elements nodes
- Field Value:
- 5
public static final short MAX_NODE_TYPE
The maximum number of node types for sizing purposes
- Field Value:
- 14
public static final short NAMESPACE_NODE
Matchs a Namespace Node - NOTE this differs from DOM
- Field Value:
- 13
public static final short PROCESSING_INSTRUCTION_NODE
Matches ProcessingInstruction
- Field Value:
- 7
public static final short TEXT_NODE
Matches elements nodes
- Field Value:
- 3
public static final short UNKNOWN_NODE
Does not match any valid node
- Field Value:
- 14
public void accept(Visitor visitor)
accept
is the method used in the Visitor Pattern.
- Parameters:
visitor
- is the visitor in the Visitor Pattern
public String asXML()
asXML
returns the textual XML representation of this node.
- Returns:
- the XML representation of this node
public Node asXPathResult(Element parent)
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
public 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.
public XPath createXPath(String xpathExpression) throws InvalidXPathException
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
public 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 exampleNode 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.
public 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 allNode
implementations.
- Returns:
- the document of this node or null if this feature is not supported or the node is not associated with a
Document
public 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
public 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
public String getNodeTypeName()
DOCUMENT ME!
- Returns:
- the name of the type of node such as "Document", "Element", "Attribute" or "Text"
public 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 allNode
implementations.
- Returns:
- the parent of this node or null if it is the root of the tree or the parent relationship is not supported.
public 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.
public String getPath(Element context)
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.
public 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.
public String getText()
Returns the text of this node.
- Returns:
- the text for this node.
public 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.
public String 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. 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.
public 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.
public 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.
public boolean matches(String xpathExpression)
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
public 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.
- 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.
public List selectNodes(String xpathExpression)
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
public List selectNodes(String xpathExpression, String comparisonXPathExpression)
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
public 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
public Object selectObject(String xpathExpression)
selectObject
evaluates an XPath expression and returns the result as anObject
. The object returned can either be aList
of one or moreNode
instances or a scalar object like aString
or aNumber
instance depending on the XPath expression.
- Parameters:
xpathExpression
- is the XPath expression to be evaluated
- Returns:
- the value of the XPath expression as a
List
ofNode
instances, aString
or aNumber
instance depending on the XPath expression.
public Node selectSingleNode(String xpathExpression)
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
public 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. This method should only be called from inside aDocument
implementation method and is not intended for general use.
- Parameters:
document
- is the new document of this node.
public void setName(String name)
Sets the text data of this node or this method will throw anUnsupportedOperationException
if it is read-only.
- Parameters:
name
- is the new name of this node
public 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. This method should only be called from inside anElement
implementation method and is not intended for general use.
- Parameters:
parent
- is the new parent of this node.
public void setText(String text)
Sets the text data of this node or this method will throw anUnsupportedOperationException
if it is read-only.
- Parameters:
text
- is the new textual value of this node
public 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
public String valueOf(String xpathExpression)
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
public void write(Writer writer) throws IOException
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