Class NodePointer
java.lang.Object
org.apache.commons.jxpath.ri.model.NodePointer
- All Implemented Interfaces:
Serializable
,Cloneable
,Comparable
,Pointer
- Direct Known Subclasses:
CollectionPointer
,ContainerPointer
,DOMAttributePointer
,DOMNodePointer
,JDOMAttributePointer
,JDOMNamespacePointer
,JDOMNodePointer
,LangAttributePointer
,NamespacePointer
,PropertyOwnerPointer
,PropertyPointer
,VariablePointer
Common superclass for Pointers of all kinds. A NodePointer maps to
a deterministic XPath that represents the location of a node in an
object graph. This XPath uses only simple axes: child, namespace and
attribute and only simple, context-independent predicates.
- Version:
- $Revision: 668329 $ $Date: 2008-06-16 16:59:48 -0500 (Mon, 16 Jun 2008) $
- See Also:
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate boolean
protected int
Index for this NodePointerprotected Locale
Localeprivate NamespaceResolver
protected NodePointer
Parent pointerprivate Object
static final String
Constant to indicate unknown namespacestatic final int
Whole collection index. -
Constructor Summary
ConstructorsModifierConstructorDescriptionprotected
NodePointer
(NodePointer parent) Create a new NodePointer.protected
NodePointer
(NodePointer parent, Locale locale) Create a new NodePointer. -
Method Summary
Modifier and TypeMethodDescriptionasPath()
Returns an XPath that maps to this Pointer.attributeIterator
(QName qname) Returns a NodeIterator that iterates over all attributes of the current node matching the supplied node name (could have a wildcard).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.clone()
Clone this NodePointer.abstract 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.private int
compareNodePointers
(NodePointer p1, int depth1, NodePointer p2, int depth2) Compare node pointers.int
createAttribute
(JXPathContext context, QName name) Called to create a non-existing attributecreateChild
(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.createChild
(JXPathContext context, QName name, int index, 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.createPath
(JXPathContext context) Called by a child pointer when it needs to create a parent object.createPath
(JXPathContext context, Object value) Called directly by JXPathContext.private static boolean
equalStrings
(String s1, String s2) Compare two strings, either of which may be null, for equality.protected String
Return a string escaping single and double quotes.protected AbstractFactory
getAbstractFactory
(JXPathContext context) Get the AbstractFactory associated with the specified JXPathContext.abstract Object
Returns the value represented by the pointer before indexing.protected String
Get the default ns uriabstract Object
Returns the object the pointer points to; does not convert it to a "canonical" type.Get the immediate parent pointer.int
getIndex()
If the pointer represents a collection, the index identifies an element of that collection.abstract int
If the pointer represents a collection (or collection element), returns the length of the collection.If the Pointer has a parent, returns the parent's locale; otherwise returns the locale specified when this Pointer was created.abstract QName
getName()
Returns the name of this node.Get the NamespaceResolver associated with this NodePointer.Returns the namespace URI associated with this Pointer.getNamespaceURI
(String prefix) Decodes a namespace prefix to the corresponding URI.getNode()
Returns the object the pointer points to; does not convert it to a "canonical" type.getNodeSetByKey
(JXPathContext context, String key, Object value) Find a NodeSet by key/value.Deprecated.1.1 Please use getNode()Get the parent pointer.getPointerByID
(JXPathContext context, String id) Locates a node by ID.getPointerByKey
(JXPathContext context, String key, String value) Locates a node by key and value.Get the root node.getValue()
By default, returnsgetNode()
, can be overridden to return a "canonical" value, like for instance a DOM element should return its string value.If this pointer manages a transparent container, like a variable, this method returns the pointer to the contents.boolean
isActual()
An actual pointer points to an existing part of an object graph, even if it is null.boolean
Returns true if the pointer represents the "attribute::" axis.abstract boolean
Returnstrue
if the value of the pointer is an array or a Collection.boolean
If true, this node is auxiliary and can only be used as an intermediate in the chain of pointers.protected boolean
isDefaultNamespace
(String prefix) Returns true if the supplied prefix represents the default namespace in the context of the current node.boolean
isLanguage
(String lang) Check whether our locale matches the specified language.abstract boolean
isLeaf()
If true, this node does not have childrenboolean
isNode()
Deprecated.Please use !isContainer()boolean
isRoot()
Returns true if this Pointer has no parent.Returns a NodeIterator that iterates over all namespaces of the value currently pointed at.namespacePointer
(String namespace) Returns a NodePointer for the specified namespace.static NodePointer
newChildNodePointer
(NodePointer parent, QName name, Object bean) Allocates an new child NodePointer by iterating through all installed NodePointerFactories until it finds one that can create a pointer.static NodePointer
newNodePointer
(QName name, Object bean, Locale locale) Allocates an entirely new NodePointer by iterating through all installed NodePointerFactories until it finds one that can create a pointer.private static void
printDeep
(NodePointer pointer, String indent) Print deepvoid
Print internal structure of a pointer for debuggingvoid
remove()
Remove the node of the object graph this pointer points to.void
setAttribute
(boolean attribute) Set to true if the pointer represents the "attribute::" axis.void
setIndex
(int index) Set the index of this NodePointer.void
setNamespaceResolver
(NamespaceResolver namespaceResolver) Set the NamespaceResolver for this NodePointer.abstract void
Converts the value to the required type and changes the corresponding object to that value.boolean
Checks if this Pointer matches the supplied NodeTest.toString()
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Field Details
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WHOLE_COLLECTION
public static final int WHOLE_COLLECTIONWhole collection index.- See Also:
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UNKNOWN_NAMESPACE
Constant to indicate unknown namespace- See Also:
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index
protected int indexIndex for this NodePointer -
attribute
private boolean attribute -
namespaceResolver
-
rootNode
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parent
Parent pointer -
locale
Locale
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Constructor Details
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NodePointer
Create a new NodePointer.- Parameters:
parent
- Pointer
-
NodePointer
Create a new NodePointer.- Parameters:
parent
- Pointerlocale
- Locale
-
-
Method Details
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newNodePointer
Allocates an entirely new NodePointer by iterating through all installed NodePointerFactories until it finds one that can create a pointer.- Parameters:
name
- QNamebean
- Objectlocale
- Locale- Returns:
- NodePointer
-
newChildNodePointer
Allocates an new child NodePointer by iterating through all installed NodePointerFactories until it finds one that can create a pointer.- Parameters:
parent
- pointername
- QNamebean
- Object- Returns:
- NodePointer
-
getNamespaceResolver
Get the NamespaceResolver associated with this NodePointer.- Returns:
- NamespaceResolver
-
setNamespaceResolver
Set the NamespaceResolver for this NodePointer.- Parameters:
namespaceResolver
- NamespaceResolver
-
getParent
Get the parent pointer.- Returns:
- NodePointer
-
getImmediateParentPointer
Get the immediate parent pointer.- Returns:
- NodePointer
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setAttribute
public void setAttribute(boolean attribute) Set to true if the pointer represents the "attribute::" axis.- Parameters:
attribute
- boolean
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isAttribute
public boolean isAttribute()Returns true if the pointer represents the "attribute::" axis.- Returns:
- boolean
-
isRoot
public boolean isRoot()Returns true if this Pointer has no parent.- Returns:
- boolean
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isLeaf
public abstract boolean isLeaf()If true, this node does not have children- Returns:
- boolean
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isNode
public boolean isNode()Deprecated.Please use !isContainer()Learn whether this pointer is considered to be a node.- Returns:
- boolean
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isContainer
public boolean isContainer()If true, this node is auxiliary and can only be used as an intermediate in the chain of pointers.- Returns:
- boolean
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getIndex
public int getIndex()If the pointer represents a collection, the index identifies an element of that collection. The default value ofindex
isWHOLE_COLLECTION
, which just means that the pointer is not indexed at all. Note: the index on NodePointer starts with 0, not 1.- Returns:
- int
-
setIndex
public void setIndex(int index) Set the index of this NodePointer.- Parameters:
index
- int
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isCollection
public abstract boolean isCollection()Returnstrue
if the value of the pointer is an array or a Collection.- Returns:
- boolean
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getLength
public abstract int getLength()If the pointer represents a collection (or collection element), returns the length of the collection. Otherwise returns 1 (even if the value is null).- Returns:
- int
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getValue
By default, returnsgetNode()
, can be overridden to return a "canonical" value, like for instance a DOM element should return its string value. -
getValuePointer
If this pointer manages a transparent container, like a variable, this method returns the pointer to the contents. Only an auxiliary (non-node) pointer can (and should) return a value pointer other than itself. Note that you probably don't want to overridegetValuePointer()
directly. Override thegetImmediateValuePointer()
method instead. ThegetValuePointer()
method is callsgetImmediateValuePointer()
and, if the result is notthis
, invokesgetValuePointer()
recursively. The idea here is to open all nested containers. Let's say we have a container within a container within a container. ThegetValuePointer()
method should then open all those containers and return the pointer to the ultimate contents. It does so with the above recursion.- Returns:
- NodePointer
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getImmediateValuePointer
- Returns:
- NodePointer is either
this
or a pointer for the immediately contained value. - See Also:
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isActual
public boolean isActual()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.- Returns:
- boolean
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getName
Returns the name of this node. Can be null.- Returns:
- QName
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getBaseValue
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.- Returns:
- Object value
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getNodeValue
Deprecated.1.1 Please use getNode()Returns the object the pointer points to; does not convert it to a "canonical" type.- Returns:
- Object node value
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getNode
Returns the object the pointer points to; does not convert it to a "canonical" type. Opens containers, properties etc and returns the ultimate contents. -
getRootNode
Get the root node.- Specified by:
getRootNode
in interfacePointer
- Returns:
- Object value of this pointer's root (top parent).
-
getImmediateNode
Returns the object the pointer points to; does not convert it to a "canonical" type.- Returns:
- Object node
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setValue
Converts the value to the required type and changes the corresponding object to that value. -
compareChildNodePointers
Compares two child NodePointers and returns a positive number, zero or a positive number according to the order of the pointers.- Parameters:
pointer1
- first pointer to be comparedpointer2
- second pointer to be compared- Returns:
- int per Java comparison conventions
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testNode
Checks if this Pointer matches the supplied NodeTest.- Parameters:
test
- the NodeTest to execute- Returns:
- true if a match
-
equalStrings
Compare two strings, either of which may be null, for equality.- Parameters:
s1
- the first String to compares2
- the second String to compare- Returns:
- true if both Strings are null, same or equal
-
createPath
Called directly by JXPathContext. Must create path and set value.- Parameters:
context
- the owning JXPathContextvalue
- the new value to set- Returns:
- created NodePointer
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remove
public void remove()Remove the node of the object graph this pointer points to. -
createPath
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.- Parameters:
context
- the owning JXPathContext- Returns:
- created NodePointer
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createChild
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.- Parameters:
context
- the owning JXPathCOntextname
- the QName at which a child should be createdindex
- child index.value
- node value to set- Returns:
- created NodePointer
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createChild
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.- Parameters:
context
- the owning JXPathCOntextname
- the QName at which a child should be createdindex
- child index.- Returns:
- created NodePointer
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createAttribute
Called to create a non-existing attribute- Parameters:
context
- the owning JXPathCOntextname
- the QName at which an attribute should be created- Returns:
- created NodePointer
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getLocale
If the Pointer has a parent, returns the parent's locale; otherwise returns the locale specified when this Pointer was created.- Returns:
- Locale for this NodePointer
-
isLanguage
Check whether our locale matches the specified language.- Parameters:
lang
- String language to check- Returns:
- true if the selected locale name starts with the specified prefix lang, case-insensitive.
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childIterator
Returns a NodeIterator that iterates over all children or all children that match the given NodeTest, starting with the specified one.- Parameters:
test
- NodeTest to filter childrenreverse
- specified iteration directionstartWith
- the NodePointer to start with- Returns:
- NodeIterator
-
attributeIterator
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.- Parameters:
qname
- the attribute name to test- Returns:
- NodeIterator
-
namespaceIterator
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.- Returns:
- NodeIterator
-
namespacePointer
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.- Parameters:
namespace
- incoming namespace- Returns:
- NodePointer for
namespace
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getNamespaceURI
Decodes a namespace prefix to the corresponding URI.- Parameters:
prefix
- prefix to decode- Returns:
- String uri
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getNamespaceURI
Returns the namespace URI associated with this Pointer.- Returns:
- String uri
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isDefaultNamespace
Returns true if the supplied prefix represents the default namespace in the context of the current node.- Parameters:
prefix
- the prefix to check- Returns:
true
if prefix is default
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getDefaultNamespaceURI
Get the default ns uri- Returns:
- String uri
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getPointerByID
Locates a node by ID.- Parameters:
context
- JXPathContext owning contextid
- String id- Returns:
- Pointer found
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getPointerByKey
Locates a node by key and value.- Parameters:
context
- owning JXPathContextkey
- key to search forvalue
- value to match- Returns:
- Pointer found
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getNodeSetByKey
Find a NodeSet by key/value.- Parameters:
context
- owning JXPathContextkey
- key to search forvalue
- value to match- Returns:
- NodeSet found
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asPath
Returns an XPath that maps to this Pointer. -
clone
Clone this NodePointer. -
toString
-
compareTo
- Specified by:
compareTo
in interfaceComparable
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compareNodePointers
Compare node pointers.- Parameters:
p1
- pointer 1depth1
- depth 1p2
- pointer 2depth2
- depth 2- Returns:
- comparison result: (< 0) -> (p1 lt p2); (0) -> (p1 eq p2); (> 0) -> (p1 gt p2)
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printPointerChain
public void printPointerChain()Print internal structure of a pointer for debugging -
escape
Return a string escaping single and double quotes.- Parameters:
string
- string to treat- Returns:
- string with any necessary changes made.
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getAbstractFactory
Get the AbstractFactory associated with the specified JXPathContext.- Parameters:
context
- JXPathContext- Returns:
- AbstractFactory
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printDeep
Print deep- Parameters:
pointer
- to printindent
- indentation level
-