org.apache.commons.jxpath.ri.model.beans
Class NullPointer

java.lang.Object
  extended by org.apache.commons.jxpath.ri.model.NodePointer
      extended by org.apache.commons.jxpath.ri.model.beans.PropertyOwnerPointer
          extended by org.apache.commons.jxpath.ri.model.beans.NullPointer
All Implemented Interfaces:
java.io.Serializable, java.lang.Cloneable, java.lang.Comparable, Pointer

public class NullPointer
extends PropertyOwnerPointer

Pointer whose value is null.

Version:
$Revision: 652915 $ $Date: 2008-05-02 16:12:57 -0500 (Fri, 02 May 2008) $
Author:
Dmitri Plotnikov
See Also:
Serialized Form

Field Summary
 
Fields inherited from class org.apache.commons.jxpath.ri.model.NodePointer
index, locale, parent, UNKNOWN_NAMESPACE, WHOLE_COLLECTION
 
Constructor Summary
NullPointer(java.util.Locale locale, java.lang.String id)
          Create a new NullPointer.
NullPointer(NodePointer parent, QName name)
          Used for the root node.
NullPointer(QName name, java.util.Locale locale)
          Create a new NullPointer.
 
Method Summary
 java.lang.String asPath()
          Returns an XPath that maps to this Pointer.
 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.
 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)
           
 java.lang.Object getBaseValue()
          Returns the value represented by the pointer before indexing.
 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.
 PropertyPointer getPropertyPointer()
          Get a PropertyPointer for this PropertyOwnerPointer.
 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 isLeaf()
          If true, this node does not have children
 
Methods inherited from class org.apache.commons.jxpath.ri.model.beans.PropertyOwnerPointer
attributeIterator, childIterator, compareChildNodePointers, createNodeIterator, getImmediateNode, isDynamicPropertyDeclarationSupported, isValidProperty, remove, setIndex, setValue
 
Methods inherited from class org.apache.commons.jxpath.ri.model.NodePointer
clone, compareTo, createAttribute, escape, getAbstractFactory, getDefaultNamespaceURI, getImmediateParentPointer, getImmediateValuePointer, getIndex, getLocale, getNamespaceResolver, getNamespaceURI, getNamespaceURI, getNode, getNodeSetByKey, getNodeValue, getParent, getPointerByID, getPointerByKey, getRootNode, getValue, getValuePointer, isAttribute, isContainer, isDefaultNamespace, isLanguage, isNode, isRoot, namespaceIterator, namespacePointer, newChildNodePointer, newNodePointer, printPointerChain, setAttribute, setNamespaceResolver, testNode, toString
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
 

Constructor Detail

NullPointer

public NullPointer(QName name,
                   java.util.Locale locale)
Create a new NullPointer.

Parameters:
name - node name
locale - Locale

NullPointer

public NullPointer(NodePointer parent,
                   QName name)
Used for the root node.

Parameters:
parent - parent pointer
name - node name

NullPointer

public NullPointer(java.util.Locale locale,
                   java.lang.String id)
Create a new NullPointer.

Parameters:
locale - Locale
id - String
Method Detail

getName

public QName getName()
Description copied from class: NodePointer
Returns the name of this node. Can be null.

Specified by:
getName in class PropertyOwnerPointer
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

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

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

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

getPropertyPointer

public PropertyPointer getPropertyPointer()
Description copied from class: PropertyOwnerPointer
Get a PropertyPointer for this PropertyOwnerPointer.

Specified by:
getPropertyPointer in class PropertyOwnerPointer
Returns:
PropertyPointer

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

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

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


Copyright © 2001-2011 Apache Software Foundation. All Rights Reserved.