net.sf.saxon.tree.wrapper

Class AbstractNodeWrapper

java.lang.Object

net.sf.saxon.tree.wrapper.AbstractNodeWrapper

All Implemented Interfaces:

Iterable<NodeInfo>, Source, SourceLocator, Location, GroundedValue<NodeInfo>, Item<NodeInfo>, NodeInfo, Sequence<NodeInfo>, VirtualNode, Locator

Direct Known Subclasses:

DOM4JNodeWrapper, DOMNodeWrapper, JDOM2NodeWrapper, JDOMNodeWrapper, XOMNodeWrapper

public abstract class AbstractNodeWrapper
extends Object
implements NodeInfo, VirtualNode

A node in the XML parse tree representing an XML element, character content, or attribute.

This implementation of the NodeInfo interface contains common code used by many "wrapper" implementations for external data models.

Author:

Michael H. Kay

Field Summary

Fields

Modifier and Type	Field and Description
protected TreeInfo	treeInfo

Fields inherited from interface net.sf.saxon.om.NodeInfo

IS_DTD_TYPE, IS_NILLED

Constructor Summary

Constructors

Constructor and Description
AbstractNodeWrapper()

Method Summary

Modifier and Type	Method and Description
AtomicSequence	atomize() Get the typed value.
boolean	equals(Object other) The equals() method compares nodes for identity.
String	getAttributeValue(String uri, String local) Get the string value of a given attribute of this node.
String	getBaseURI() Get the Base URI for the node, that is, the URI used for resolving a relative URI contained in the node.
int	getColumnNumber() Get column number
NamespaceBinding[]	getDeclaredNamespaces(NamespaceBinding[] buffer) Get all namespace declarations and undeclarations defined on this element.
String	getDisplayName() Get the display name of this node.
int	getFingerprint() Get the fingerprint of the node
int	getLineNumber() Get line number
NamePool	getNamePool() Get the name pool for this node
Object	getRealNode() Get the node underlying this virtual node.
NodeInfo	getRoot() Get the root node - always a document node with this tree implementation
String	getStringValue() Return the string value of the node.
String	getSystemId() Get the System ID for the node.
TreeInfo	getTreeInfo() Get information about the tree to which this NodeInfo belongs
boolean	hasChildNodes() Determine whether the node has any children.
boolean	hasFingerprint() Test whether a fingerprint is available for the node name
int	hashCode() The hashCode() method obeys the contract for hashCode(): that is, if two objects are equal (represent the same node) then they must have the same hashCode()
protected abstract AxisIterator	iterateAttributes(NodeTest nodeTest) Return an iterator over the attributes of this element node.
AxisIterator	iterateAxis(byte axisNumber) Return an iteration over the nodes reached by the given axis from this node
AxisIterator	iterateAxis(byte axisNumber, NodeTest nodeTest) Return an iteration over the nodes reached by the given axis from this node.
protected abstract AxisIterator	iterateChildren(NodeTest nodeTest) Return an iterator over the children of this node.
protected AxisIterator	iterateDescendants(NodeTest nodeTest, boolean includeSelf) Return an iterator over the descendants of this node.
protected abstract AxisIterator	iterateSiblings(NodeTest nodeTest, boolean forwards) Return an iterator over the siblings of this node.
Location	saveLocation() Get an immutable copy of this Location object.
void	setSystemId(String uri) Set the system ID.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface net.sf.saxon.tree.wrapper.VirtualNode

getUnderlyingNode

Methods inherited from interface net.sf.saxon.om.NodeInfo

compareOrder, copy, generateId, getConfiguration, getGenre, getLocalPart, getNodeKind, getParent, getPrefix, getPublicId, getSchemaType, getURI, isId, isIdref, isNilled, isSameNodeInfo, isStreamed, toShortString

Methods inherited from interface net.sf.saxon.om.Item

getLength, getStringValueCS, head, itemAt, iterate, iterator, reduce, subsequence, toGroundedValue

Methods inherited from interface net.sf.saxon.om.GroundedValue

asIterable, effectiveBooleanValue, materialize

Methods inherited from interface net.sf.saxon.om.Sequence

makeRepeatable

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

treeInfo

protected TreeInfo treeInfo

Constructor Detail

AbstractNodeWrapper

public AbstractNodeWrapper()

Method Detail

getTreeInfo

public TreeInfo getTreeInfo()

Description copied from interface: NodeInfo

Get information about the tree to which this NodeInfo belongs

Specified by:

getTreeInfo in interface NodeInfo

Returns:

the TreeInfo

getRealNode

public final Object getRealNode()

Get the node underlying this virtual node. If this is a VirtualNode the method will automatically drill down through several layers of wrapping.

Specified by:

getRealNode in interface VirtualNode

Returns:

The underlying node.

getNamePool

public NamePool getNamePool()

Get the name pool for this node

Returns:

the NamePool

atomize

public AtomicSequence atomize()
                       throws XPathException

Get the typed value.

Specified by:

atomize in interface Item<NodeInfo>

Specified by:

atomize in interface NodeInfo

Returns:

the typed value. This will either be a single AtomicValue or a value whose items are atomic values.

Throws:

XPathException - if the node has no typed value, for example if it is an element node with element-only content

Since:

8.5 - signature changed in 9.5

equals

public boolean equals(Object other)

The equals() method compares nodes for identity. It is defined to give the same result as isSameNodeInfo().

Specified by:

equals in interface NodeInfo

Overrides:

equals in class Object

Parameters:

other - the node to be compared with this node

Returns:

true if this NodeInfo object and the supplied NodeInfo object represent the same node in the tree.

Since:

8.7 Previously, the effect of the equals() method was not defined. Callers should therefore be aware that third party implementations of the NodeInfo interface may not implement the correct semantics. It is safer to use isSameNodeInfo() for this reason. The equals() method has been defined because it is useful in contexts such as a Java Set or HashMap.

hashCode

public int hashCode()

The hashCode() method obeys the contract for hashCode(): that is, if two objects are equal (represent the same node) then they must have the same hashCode()

Specified by:

hashCode in interface NodeInfo

Overrides:

hashCode in class Object

Since:

8.7 Previously, the effect of the equals() and hashCode() methods was not defined. Callers should therefore be aware that third party implementations of the NodeInfo interface may not implement the correct semantics.

getSystemId

public String getSystemId()

Get the System ID for the node.

Specified by:

getSystemId in interface Source

Specified by:

getSystemId in interface SourceLocator

Specified by:

getSystemId in interface Location

Specified by:

getSystemId in interface NodeInfo

Specified by:

getSystemId in interface Locator

Returns:

the System Identifier of the entity in the source document containing the node, or null if not known. Note this is not the same as the base URI: the base URI can be modified by xml:base, but the system ID cannot.

setSystemId

public void setSystemId(String uri)

Set the system ID. Required because NodeInfo implements the JAXP Source interface

Specified by:

setSystemId in interface Source

Parameters:

uri - the system ID.

getBaseURI

public String getBaseURI()

Get the Base URI for the node, that is, the URI used for resolving a relative URI contained in the node.

Specified by:

getBaseURI in interface NodeInfo

Returns:

the base URI of the node, taking into account xml:base attributes if present

getLineNumber

public int getLineNumber()

Get line number

Specified by:

getLineNumber in interface SourceLocator

Specified by:

getLineNumber in interface Location

Specified by:

getLineNumber in interface NodeInfo

Specified by:

getLineNumber in interface Locator

Returns:

the line number of the node in its original source document; or -1 if not available. Always returns -1 in this implementation.

getColumnNumber

public int getColumnNumber()

Get column number

Specified by:

getColumnNumber in interface SourceLocator

Specified by:

getColumnNumber in interface Location

Specified by:

getColumnNumber in interface NodeInfo

Specified by:

getColumnNumber in interface Locator

Returns:

the column number of the node in its original source document; or -1 if not available

saveLocation

public Location saveLocation()

Get an immutable copy of this Location object. By default Location objects may be mutable, so they should not be saved for later use. The result of this operation holds the same location information, but in an immutable form.

Specified by:

saveLocation in interface Location

getStringValue

public String getStringValue()

Return the string value of the node. The interpretation of this depends on the type of node. For an element it is the accumulated character content of the element, including descendant elements.

Specified by:

getStringValue in interface GroundedValue<NodeInfo>

Specified by:

getStringValue in interface Item<NodeInfo>

Specified by:

getStringValue in interface NodeInfo

Returns:

the string value of the node

See Also:

Item.getStringValueCS()

getDisplayName

public String getDisplayName()

Get the display name of this node. For elements and attributes this is [prefix:]localname. For unnamed nodes, it is an empty string.

Specified by:

getDisplayName in interface NodeInfo

Returns:

The display name of this node. For a node with no name, return an empty string.

getAttributeValue

public String getAttributeValue(String uri,
                                String local)

Get the string value of a given attribute of this node.

The default implementation is suitable for nodes other than elements.

Specified by:

getAttributeValue in interface NodeInfo

Parameters:

uri - the namespace URI of the attribute name. Supply the empty string for an attribute that is in no namespace

local - the local part of the attribute name.

Returns:

the attribute value if it exists, or null if it does not exist. Always returns null if this node is not an element.

Since:

9.4

iterateAxis

public AxisIterator iterateAxis(byte axisNumber)

Return an iteration over the nodes reached by the given axis from this node

Specified by:

iterateAxis in interface NodeInfo

Parameters:

axisNumber - the axis to be used

Returns:

a SequenceIterator that scans the nodes reached by the axis in turn.

See Also:

AxisInfo

iterateAxis

public AxisIterator iterateAxis(byte axisNumber,
                                NodeTest nodeTest)

Return an iteration over the nodes reached by the given axis from this node.

This superclass provides implementations of the ancestor, ancestor-or-self, following, namespace, parent, preceding, self, and preceding-or-ancestor axes. The other axes are implemented by calling methods iterateAttributes(), iterateChildren(), iterateDescendants(), and iterateSiblings(), which must be provided in a subclass.

Specified by:

iterateAxis in interface NodeInfo

Parameters:

axisNumber - the axis to be used

nodeTest - A pattern to be matched by the returned nodes

Returns:

a SequenceIterator that scans the nodes reached by the axis in turn.

See Also:

AxisInfo

iterateAttributes

protected abstract AxisIterator iterateAttributes(NodeTest nodeTest)

Return an iterator over the attributes of this element node. This method is only called after checking that the node is an element.

Parameters:

nodeTest - a test that the returned attributes must satisfy

Returns:

an iterator over the attribute nodes. The order of the result, although arbitrary, must be consistent with document order.

iterateChildren

protected abstract AxisIterator iterateChildren(NodeTest nodeTest)

Return an iterator over the children of this node. This method is only called after checking that the node is an element or document.

Parameters:

nodeTest - a test that the returned attributes must satisfy

Returns:

an iterator over the child nodes, in document order.

iterateSiblings

protected abstract AxisIterator iterateSiblings(NodeTest nodeTest,
                                                boolean forwards)

Return an iterator over the siblings of this node. This method is only called after checking that the node is an element, text, comment, or PI node.

Parameters:

nodeTest - a test that the returned siblings must satisfy

forwards - true for following siblings, false for preceding siblings

Returns:

an iterator over the sibling nodes, in axis order.

iterateDescendants

protected AxisIterator iterateDescendants(NodeTest nodeTest,
                                          boolean includeSelf)

Return an iterator over the descendants of this node. This method is only called after checking that the node is an element or document node.

Parameters:

nodeTest - a test that the returned descendants must satisfy

includeSelf - true if this node is to be included in the result

Returns:

an iterator over the sibling nodes, in axis order.

getDeclaredNamespaces

public NamespaceBinding[] getDeclaredNamespaces(NamespaceBinding[] buffer)

Get all namespace declarations and undeclarations defined on this element.

This method is intended primarily for internal use. User applications needing information about the namespace context of a node should use iterateAxis(Axis.NAMESPACE). (However, not all implementations support the namespace axis, whereas all implementations are required to support this method.)

This implementation of the method is suitable for all nodes other than elements; it returns an empty array.

Specified by:

getDeclaredNamespaces in interface NodeInfo

Parameters:

buffer - If this is non-null, and the result array fits in this buffer, then the result may overwrite the contents of this array, to avoid the cost of allocating a new array on the heap.

Returns:

An array of namespace binding objects representing the namespace declarations and undeclarations present on this element. For a node other than an element, return null. If the uri part is "", then this is a namespace undeclaration rather than a declaration. The XML namespace is never included in the list. If the supplied array is larger than required, then the first unused entry will be set to null.

For a node other than an element, the method returns null.

getRoot

public NodeInfo getRoot()

Get the root node - always a document node with this tree implementation

Specified by:

getRoot in interface NodeInfo

Returns:

the NodeInfo representing the containing document

hasChildNodes

public boolean hasChildNodes()

Determine whether the node has any children. This implementation calls iterateAxis, so the subclass implementation of iterateAxis must avoid calling this method.

Specified by:

hasChildNodes in interface NodeInfo

Returns:

True if the node has one or more children

getFingerprint

public int getFingerprint()

Get the fingerprint of the node

Specified by:

getFingerprint in interface NodeInfo

Returns:

the node's fingerprint, or -1 for an unnamed node

Throws:

UnsupportedOperationException - if this method is called for a node where hasFingerprint() returns false;

hasFingerprint

public boolean hasFingerprint()

Test whether a fingerprint is available for the node name

Specified by:

hasFingerprint in interface NodeInfo

Returns:

true if the implementation of this node provides fingerprints.