Class DefaultNavigator

java.lang.Object

org.jaxen.DefaultNavigator

All Implemented Interfaces:

Serializable, Navigator

Direct Known Subclasses:

DocumentNavigator, DocumentNavigator, DocumentNavigator, DocumentNavigator, DocumentNavigator

public abstract class DefaultNavigator
extends Object
implements Navigator

Default implementation of Navigator.

This implementation is an abstract class, since some required operations cannot be implemented without additional knowledge of the object model.

When possible, default method implementations build upon each other, to reduce the number of methods required to be implemented for each object model. All methods, of course, may be overridden, to provide more-efficient implementations.

Author:

bob mcwhirter (bob@werken.com), Erwin Bolwidt (ejb@klomp.org)

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
DefaultNavigator()

Method Summary

Modifier and Type	Method	Description
Iterator	getAncestorAxisIterator(Object contextNode)	Retrieve an Iterator matching the ancestor XPath axis.
Iterator	getAncestorOrSelfAxisIterator(Object contextNode)	Retrieve an Iterator matching the ancestor-or-self XPath axis.
Iterator	getAttributeAxisIterator(Object contextNode)	Retrieve an Iterator matching the attribute XPath axis.
Iterator	getChildAxisIterator(Object contextNode)	Throws UnsupportedAxisException.
Iterator	getDescendantAxisIterator(Object contextNode)	Retrieve an Iterator matching the descendant XPath axis.
Iterator	getDescendantOrSelfAxisIterator(Object contextNode)	Retrieve an Iterator matching the descendant-or-self XPath axis.
Object	getDocument(String url)	Default implementation that always returns null.
Object	getDocumentNode(Object contextNode)	Returns null.
Object	getElementById(Object contextNode, String elementId)	Default implementation that cannot find elements.
Iterator	getFollowingAxisIterator(Object contextNode)	Retrieve an Iterator matching the following XPath axis.
Iterator	getFollowingSiblingAxisIterator(Object contextNode)	Retrieve an Iterator matching the following-sibling XPath axis.
Iterator	getNamespaceAxisIterator(Object contextNode)	Throws UnsupportedAxisException.
short	getNodeType(Object node)	Returns a number that identifies the type of node that the given object represents in this navigator.
Iterator	getParentAxisIterator(Object contextNode)	Throws UnsupportedAxisException.
Object	getParentNode(Object contextNode)	Default inefficient implementation.
Iterator	getPrecedingAxisIterator(Object contextNode)	Retrieve an Iterator matching the preceding XPath axis.
Iterator	getPrecedingSiblingAxisIterator(Object contextNode)	Retrieve an Iterator matching the preceding-sibling XPath axis.
String	getProcessingInstructionData(Object contextNode)	Returns null.
String	getProcessingInstructionTarget(Object contextNode)	Returns null.
Iterator	getSelfAxisIterator(Object contextNode)	Retrieve an Iterator matching the self XPath axis.
String	translateNamespacePrefixToUri(String prefix, Object contextNode)	Returns null.

Methods inherited from class Object

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

Methods inherited from interface Navigator

getAttributeName, getAttributeNamespaceUri, getAttributeQName, getAttributeStringValue, getCommentStringValue, getElementName, getElementNamespaceUri, getElementQName, getElementStringValue, getNamespacePrefix, getNamespaceStringValue, getTextStringValue, isAttribute, isComment, isDocument, isElement, isNamespace, isProcessingInstruction, isText, parseXPath

Constructor Details

DefaultNavigator

public DefaultNavigator()

Method Details

getChildAxisIterator

public Iterator getChildAxisIterator(Object contextNode)
                              throws UnsupportedAxisException

Throws UnsupportedAxisException. Subclasses should override this method.

Specified by:

getChildAxisIterator in interface Navigator

Parameters:

contextNode - the node to start from

Returns:

never returns

Throws:

UnsupportedAxisException - always

getDescendantAxisIterator

public Iterator getDescendantAxisIterator(Object contextNode)
                                   throws UnsupportedAxisException

Retrieve an Iterator matching the descendant XPath axis.

Specified by:

getDescendantAxisIterator in interface Navigator

Parameters:

contextNode - the original context node

Returns:

an Iterator capable of traversing the axis, not null

Throws:

UnsupportedAxisException - if the semantics of the desscendant axis are not supported by this object model

getParentAxisIterator

public Iterator getParentAxisIterator(Object contextNode)
                               throws UnsupportedAxisException

Throws UnsupportedAxisException. Subclasses should override this method.

Specified by:

getParentAxisIterator in interface Navigator

Parameters:

contextNode - the node to start from

Returns:

never returns

Throws:

UnsupportedAxisException - always

getAncestorAxisIterator

public Iterator getAncestorAxisIterator(Object contextNode)
                                 throws UnsupportedAxisException

Retrieve an Iterator matching the ancestor XPath axis.

Specified by:

getAncestorAxisIterator in interface Navigator

Parameters:

contextNode - the original context node

Returns:

an Iterator capable of traversing the axis, not null

Throws:

UnsupportedAxisException - if the semantics of the ancestor axis are not supported by this object model

getFollowingSiblingAxisIterator

public Iterator getFollowingSiblingAxisIterator(Object contextNode)
                                         throws UnsupportedAxisException

Retrieve an Iterator matching the following-sibling XPath axis.

Specified by:

getFollowingSiblingAxisIterator in interface Navigator

Parameters:

contextNode - the original context node

Returns:

an Iterator capable of traversing the axis, not null

Throws:

UnsupportedAxisException - if the semantics of the following-sibling axis are not supported by this object model

getPrecedingSiblingAxisIterator

public Iterator getPrecedingSiblingAxisIterator(Object contextNode)
                                         throws UnsupportedAxisException

Retrieve an Iterator matching the preceding-sibling XPath axis.

Specified by:

getPrecedingSiblingAxisIterator in interface Navigator

Parameters:

contextNode - the original context node

Returns:

an Iterator capable of traversing the axis, not null

Throws:

UnsupportedAxisException - if the semantics of the preceding-sibling axis are not supported by this object model

getFollowingAxisIterator

public Iterator getFollowingAxisIterator(Object contextNode)
                                  throws UnsupportedAxisException

Retrieve an Iterator matching the following XPath axis.

Specified by:

getFollowingAxisIterator in interface Navigator

Parameters:

contextNode - the original context node

Returns:

an Iterator capable of traversing the axis, not null

Throws:

UnsupportedAxisException - if the semantics of the following axis are not supported by this object model

getPrecedingAxisIterator

public Iterator getPrecedingAxisIterator(Object contextNode)
                                  throws UnsupportedAxisException

Retrieve an Iterator matching the preceding XPath axis.

Specified by:

getPrecedingAxisIterator in interface Navigator

Parameters:

contextNode - the original context node

Returns:

an Iterator capable of traversing the axis, not null

Throws:

UnsupportedAxisException - if the semantics of the preceding axis are not supported by this object model

getAttributeAxisIterator

public Iterator getAttributeAxisIterator(Object contextNode)
                                  throws UnsupportedAxisException

Retrieve an Iterator matching the attribute XPath axis.

Specified by:

getAttributeAxisIterator in interface Navigator

Parameters:

contextNode - the original context node

Returns:

an Iterator capable of traversing the axis, not null

Throws:

UnsupportedAxisException - if the semantics of the attribute axis are not supported by this object model

getNamespaceAxisIterator

public Iterator getNamespaceAxisIterator(Object contextNode)
                                  throws UnsupportedAxisException

Throws UnsupportedAxisException. Subclasses that support the namespace axis must override this method.

Specified by:

getNamespaceAxisIterator in interface Navigator

Parameters:

contextNode - the node to start from

Returns:

never returns

Throws:

UnsupportedAxisException - always

getSelfAxisIterator

public Iterator getSelfAxisIterator(Object contextNode)
                             throws UnsupportedAxisException

Retrieve an Iterator matching the self XPath axis.

Specified by:

getSelfAxisIterator in interface Navigator

Parameters:

contextNode - the original context node

Returns:

an Iterator capable of traversing the axis, not null

Throws:

UnsupportedAxisException - if the semantics of the self axis are not supported by this object model

getDescendantOrSelfAxisIterator

public Iterator getDescendantOrSelfAxisIterator(Object contextNode)
                                         throws UnsupportedAxisException

Retrieve an Iterator matching the descendant-or-self XPath axis.

Specified by:

getDescendantOrSelfAxisIterator in interface Navigator

Parameters:

contextNode - the original context node

Returns:

an Iterator capable of traversing the axis, not null

Throws:

UnsupportedAxisException - if the semantics of the descendant-or-self axis are not supported by this object model

getAncestorOrSelfAxisIterator

public Iterator getAncestorOrSelfAxisIterator(Object contextNode)
                                       throws UnsupportedAxisException

Retrieve an Iterator matching the ancestor-or-self XPath axis.

Specified by:

getAncestorOrSelfAxisIterator in interface Navigator

Parameters:

contextNode - the original context node

Returns:

an Iterator capable of traversing the axis, not null

Throws:

UnsupportedAxisException - if the semantics of the ancestor-or-self axis are not supported by this object model

getDocumentNode

public Object getDocumentNode(Object contextNode)

Returns null.

Specified by:

getDocumentNode in interface Navigator

Parameters:

contextNode - the node to start from

Returns:

null

See Also:

• Navigator.isDocument(Object)

translateNamespacePrefixToUri

public String translateNamespacePrefixToUri(String prefix,
 Object contextNode)

Returns null.

Specified by:

translateNamespacePrefixToUri in interface Navigator

Parameters:

prefix - the prefix to translate

contextNode - the node to start from

Returns:

null

See Also:

• NamespaceContext

getProcessingInstructionTarget

public String getProcessingInstructionTarget(Object contextNode)

Returns null.

Specified by:

getProcessingInstructionTarget in interface Navigator

Parameters:

contextNode - the node to start from

Returns:

null

getProcessingInstructionData

public String getProcessingInstructionData(Object contextNode)

Returns null.

Specified by:

getProcessingInstructionData in interface Navigator

Parameters:

contextNode - the node to start from

Returns:

null

getNodeType

public short getNodeType(Object node)

Returns a number that identifies the type of node that the given object represents in this navigator.

Specified by:

getNodeType in interface Navigator

Parameters:

node - ????

Returns:

????

See Also:

• Pattern

getParentNode

public Object getParentNode(Object contextNode)
                     throws UnsupportedAxisException

Default inefficient implementation. Subclasses should override this method.

Specified by:

getParentNode in interface Navigator

Parameters:

contextNode - the node whose parent to return

Returns:

the parent node

Throws:

UnsupportedAxisException - if the parent axis is not supported

See Also:

• Navigator.isDocument(Object)
• Navigator.isElement(Object)

getDocument

public Object getDocument(String url)
                   throws FunctionCallException

Default implementation that always returns null. Override in subclass if the subclass can load documents.

Specified by:

getDocument in interface Navigator

Parameters:

url - the URL of the document to load

Returns:

null

Throws:

FunctionCallException - if an error occurs while loading the URL; e.g. an I/O error or the document is malformed

getElementById

public Object getElementById(Object contextNode,
 String elementId)

Default implementation that cannot find elements. Override in subclass if subclass knows about attribute types.

Specified by:

getElementById in interface Navigator

Parameters:

contextNode - a node from the document in which to look for the id

elementId - id to look for

Returns:

null