Package org.apache.commons.jxpath.ri.model

Class VariablePointer

java.lang.Object

org.apache.commons.jxpath.ri.model.NodePointer

org.apache.commons.jxpath.ri.model.VariablePointer

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.lang.Comparable, Pointer

public class VariablePointer
extends NodePointer

Pointer to a context variable.

Version:

$Revision: 652884 $ $Date: 2008-05-02 15:02:00 -0500 (Fri, 02 May 2008) $

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	actual
private QName	name
private static long	serialVersionUID
private NodePointer	valuePointer
private Variables	variables

Fields inherited from class org.apache.commons.jxpath.ri.model.NodePointer

index, locale, parent, UNKNOWN_NAMESPACE, WHOLE_COLLECTION

Constructor Summary

Constructors

Constructor	Description
VariablePointer(QName name)	Create a new (non-actual) VariablePointer.
VariablePointer(Variables variables, QName name)	Create a new VariablePointer.

Method Summary

Modifier and Type	Method	Description
java.lang.String	asPath()	Returns an XPath that maps to this Pointer.
NodeIterator	attributeIterator(QName name)	Returns a NodeIterator that iterates over all attributes of the current node matching the supplied node name (could have a wildcard).
NodeIterator	childIterator(NodeTest test, boolean reverse, NodePointer startWith)	Returns a NodeIterator that iterates over all children or all children that match the given NodeTest, starting with the specified one.
int	compareChildNodePointers(NodePointer pointer1, NodePointer pointer2)	Compares two child NodePointers and returns a positive number, zero or a positive number according to the order of the pointers.
NodePointer	createChild(JXPathContext context, QName name, int index)	Called by a child pointer when it needs to create a parent object for a non-existent collection element.
NodePointer	createChild(JXPathContext context, QName name, int index, java.lang.Object value)	Called by a child pointer if that child needs to assign the value supplied in the createPath(context, value) call to a non-existent node.
private java.lang.Object	createCollection(JXPathContext context, int index)	Create a collection.
NodePointer	createPath(JXPathContext context)	Called by a child pointer when it needs to create a parent object.
NodePointer	createPath(JXPathContext context, java.lang.Object value)	Called directly by JXPathContext.
boolean	equals(java.lang.Object object)
protected void	findVariables(JXPathContext context)	Assimilate the Variables instance associated with the specified context.
java.lang.Object	getBaseValue()	Returns the value represented by the pointer before indexing.
java.lang.Object	getImmediateNode()	Returns the object the pointer points to; does not convert it to a "canonical" type.
NodePointer	getImmediateValuePointer()
int	getLength()	If the pointer represents a collection (or collection element), returns the length of the collection.
QName	getName()	Returns the name of this node.
int	hashCode()
boolean	isActual()	An actual pointer points to an existing part of an object graph, even if it is null.
boolean	isCollection()	Returns true if the value of the pointer is an array or a Collection.
boolean	isContainer()	If true, this node is auxiliary and can only be used as an intermediate in the chain of pointers.
boolean	isLeaf()	If true, this node does not have children
NodeIterator	namespaceIterator()	Returns a NodeIterator that iterates over all namespaces of the value currently pointed at.
NodePointer	namespacePointer(java.lang.String name)	Returns a NodePointer for the specified namespace.
void	remove()	Remove the node of the object graph this pointer points to.
void	setIndex(int index)	Set the index of this NodePointer.
void	setValue(java.lang.Object value)	Converts the value to the required type and changes the corresponding object to that value.
boolean	testNode(NodeTest nodeTest)	Checks if this Pointer matches the supplied NodeTest.

Methods inherited from class org.apache.commons.jxpath.ri.model.NodePointer

clone, compareTo, createAttribute, escape, getAbstractFactory, getDefaultNamespaceURI, getImmediateParentPointer, getIndex, getLocale, getNamespaceResolver, getNamespaceURI, getNamespaceURI, getNode, getNodeSetByKey, getNodeValue, getParent, getPointerByID, getPointerByKey, getRootNode, getValue, getValuePointer, isAttribute, isDefaultNamespace, isLanguage, isNode, isRoot, newChildNodePointer, newNodePointer, printPointerChain, setAttribute, setNamespaceResolver, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

variables

private Variables variables

name

private QName name

valuePointer

private NodePointer valuePointer

actual

private boolean actual

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

Constructor Detail

VariablePointer

public VariablePointer(Variables variables,
                       QName name)

Create a new VariablePointer.

Parameters:

variables - Variables instance

name - variable name

VariablePointer

public VariablePointer(QName name)

Create a new (non-actual) VariablePointer.

Parameters:

name - variable name

Method Detail

isContainer

public boolean isContainer()

Description copied from class: NodePointer

If true, this node is auxiliary and can only be used as an intermediate in the chain of pointers.

Overrides:

isContainer in class NodePointer

Returns:

boolean

getName

public QName getName()

Description copied from class: NodePointer

Returns the name of this node. Can be null.

Specified by:

getName in class NodePointer

Returns:

QName

getBaseValue

public java.lang.Object getBaseValue()

Description copied from class: NodePointer

Returns the value represented by the pointer before indexing. So, if the node represents an element of a collection, this method returns the collection itself.

Specified by:

getBaseValue in class NodePointer

Returns:

Object value

isLeaf

public boolean isLeaf()

Description copied from class: NodePointer

If true, this node does not have children

Specified by:

isLeaf in class NodePointer

Returns:

boolean

isCollection

public boolean isCollection()

Description copied from class: NodePointer

Returns true if the value of the pointer is an array or a Collection.

Specified by:

isCollection in class NodePointer

Returns:

boolean

getImmediateNode

public java.lang.Object getImmediateNode()

Description copied from class: NodePointer

Returns the object the pointer points to; does not convert it to a "canonical" type.

Specified by:

getImmediateNode in class NodePointer

Returns:

Object node

setValue

public void setValue(java.lang.Object value)

Description copied from class: NodePointer

Converts the value to the required type and changes the corresponding object to that value.

Specified by:

setValue in interface Pointer

Specified by:

setValue in class NodePointer

Parameters:

value - the value to set

isActual

public boolean isActual()

Description copied from class: NodePointer

An actual pointer points to an existing part of an object graph, even if it is null. A non-actual pointer represents a part that does not exist at all. For instance consider the pointer "/address/street". If both address and street are not null, the pointer is actual. If address is not null, but street is null, the pointer is still actual. If address is null, the pointer is not actual. (In JavaBeans) if address is not a property of the root bean, a Pointer for this path cannot be obtained at all - actual or otherwise.

Overrides:

isActual in class NodePointer

Returns:

boolean

setIndex

public void setIndex(int index)

Description copied from class: NodePointer

Set the index of this NodePointer.

Overrides:

setIndex in class NodePointer

Parameters:

index - int

getImmediateValuePointer

public NodePointer getImmediateValuePointer()

Overrides:

getImmediateValuePointer in class NodePointer

Returns:

NodePointer is either this or a pointer for the immediately contained value.

See Also:

NodePointer.getValuePointer()

getLength

public int getLength()

Description copied from class: NodePointer

If the pointer represents a collection (or collection element), returns the length of the collection. Otherwise returns 1 (even if the value is null).

Specified by:

getLength in class NodePointer

Returns:

int

createPath

public NodePointer createPath(JXPathContext context,
                              java.lang.Object value)

Description copied from class: NodePointer

Called directly by JXPathContext. Must create path and set value.

Overrides:

createPath in class NodePointer

Parameters:

context - the owning JXPathContext

value - the new value to set

Returns:

created NodePointer

createPath

public NodePointer createPath(JXPathContext context)

Description copied from class: NodePointer

Called by a child pointer when it needs to create a parent object. Must create an object described by this pointer and return a new pointer that properly describes the new object.

Overrides:

createPath in class NodePointer

Parameters:

context - the owning JXPathContext

Returns:

created NodePointer

createChild

public NodePointer createChild(JXPathContext context,
                               QName name,
                               int index)

Description copied from class: NodePointer

Called by a child pointer when it needs to create a parent object for a non-existent collection element. It may have to expand the collection, then create an element object and return a new pointer describing the newly created element.

Overrides:

createChild in class NodePointer

Parameters:

context - the owning JXPathCOntext

name - the QName at which a child should be created

index - child index.

Returns:

created NodePointer

createChild

public NodePointer createChild(JXPathContext context,
                               QName name,
                               int index,
                               java.lang.Object value)

Description copied from class: NodePointer

Called by a child pointer if that child needs to assign the value supplied in the createPath(context, value) call to a non-existent node. This method may have to expand the collection in order to assign the element.

Overrides:

createChild in class NodePointer

Parameters:

context - the owning JXPathCOntext

name - the QName at which a child should be created

index - child index.

value - node value to set

Returns:

created NodePointer

createCollection

private java.lang.Object createCollection(JXPathContext context,
                                          int index)

Create a collection.

Parameters:

context - JXPathContext

index - collection index

Returns:

Object

remove

public void remove()

Description copied from class: NodePointer

Remove the node of the object graph this pointer points to.

Overrides:

remove in class NodePointer

findVariables

protected void findVariables(JXPathContext context)

Assimilate the Variables instance associated with the specified context.

Parameters:

context - JXPathContext to search

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object object)

Overrides:

equals in class java.lang.Object

asPath

public java.lang.String asPath()

Description copied from class: NodePointer

Returns an XPath that maps to this Pointer.

Specified by:

asPath in interface Pointer

Overrides:

asPath in class NodePointer

Returns:

String xpath expression

childIterator

public NodeIterator childIterator(NodeTest test,
                                  boolean reverse,
                                  NodePointer startWith)

Description copied from class: NodePointer

Returns a NodeIterator that iterates over all children or all children that match the given NodeTest, starting with the specified one.

Overrides:

childIterator in class NodePointer

Parameters:

test - NodeTest to filter children

reverse - specified iteration direction

startWith - the NodePointer to start with

Returns:

NodeIterator

attributeIterator

public NodeIterator attributeIterator(QName name)

Description copied from class: NodePointer

Returns a NodeIterator that iterates over all attributes of the current node matching the supplied node name (could have a wildcard). May return null if the object does not support the attributes.

Overrides:

attributeIterator in class NodePointer

Parameters:

name - the attribute name to test

Returns:

NodeIterator

namespaceIterator

public NodeIterator namespaceIterator()

Description copied from class: NodePointer

Returns a NodeIterator that iterates over all namespaces of the value currently pointed at. May return null if the object does not support the namespaces.

Overrides:

namespaceIterator in class NodePointer

Returns:

NodeIterator

namespacePointer

public NodePointer namespacePointer(java.lang.String name)

Description copied from class: NodePointer

Returns a NodePointer for the specified namespace. Will return null if namespaces are not supported. Will return UNKNOWN_NAMESPACE if there is no such namespace.

Overrides:

namespacePointer in class NodePointer

Parameters:

name - incoming namespace

Returns:

NodePointer for namespace

testNode

public boolean testNode(NodeTest nodeTest)

Description copied from class: NodePointer

Checks if this Pointer matches the supplied NodeTest.

Overrides:

testNode in class NodePointer

Parameters:

nodeTest - the NodeTest to execute

Returns:

true if a match

compareChildNodePointers

public int compareChildNodePointers(NodePointer pointer1,
                                    NodePointer pointer2)

Description copied from class: NodePointer

Compares two child NodePointers and returns a positive number, zero or a positive number according to the order of the pointers.

Specified by:

compareChildNodePointers in class NodePointer

Parameters:

pointer1 - first pointer to be compared

pointer2 - second pointer to be compared

Returns:

int per Java comparison conventions