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
public abstract class NodePointer extends Object implements Pointer
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) $
Author:
Dmitri Plotnikov
See Also:

  • Field Details

    • WHOLE_COLLECTION

      public static final int WHOLE_COLLECTION
      Whole collection index.
      See Also:

    • UNKNOWN_NAMESPACE

      public static final String UNKNOWN_NAMESPACE
      Constant to indicate unknown namespace
      See Also:

    • index

      protected int index
      Index for this NodePointer

    • attribute

      private boolean attribute

    • namespaceResolver

      private NamespaceResolver namespaceResolver

    • rootNode

      private transient Object rootNode

    • parent

      protected NodePointer parent
      Parent pointer

    • locale

      protected Locale locale
      Locale

  • Constructor Details

    • NodePointer

      protected NodePointer(NodePointer parent)
      Create a new NodePointer.
      Parameters:
      parent - Pointer

    • NodePointer

      protected NodePointer(NodePointer parent, Locale locale)
      Create a new NodePointer.
      Parameters:
      parent - Pointer
      locale - Locale

  • Method Details

    • newNodePointer

      public 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.
      Parameters:
      name - QName
      bean - Object
      locale - Locale
      Returns:
      NodePointer

    • newChildNodePointer

      public 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.
      Parameters:
      parent - pointer
      name - QName
      bean - Object
      Returns:
      NodePointer

    • getNamespaceResolver

      public NamespaceResolver getNamespaceResolver()
      Get the NamespaceResolver associated with this NodePointer.
      Returns:
      NamespaceResolver

    • setNamespaceResolver

      public void setNamespaceResolver(NamespaceResolver namespaceResolver)
      Set the NamespaceResolver for this NodePointer.
      Parameters:
      namespaceResolver - NamespaceResolver

    • getParent

      public NodePointer getParent()
      Get the parent pointer.
      Returns:
      NodePointer

    • getImmediateParentPointer

      public NodePointer getImmediateParentPointer()
      Get the immediate parent pointer.
      Returns:
      NodePointer

    • setAttribute

      public void setAttribute(boolean attribute)
      Set to true if the pointer represents the "attribute::" axis.
      Parameters:
      attribute - boolean

    • 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

    • isLeaf

      public abstract boolean isLeaf()
      If true, this node does not have children
      Returns:
      boolean

    • isNode

      public boolean isNode()
      Deprecated.
      Please use !isContainer()
      Learn whether this pointer is considered to be a node.
      Returns:
      boolean

    • 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

    • getIndex

      public int getIndex()
      If the pointer represents a collection, the index identifies an element of that collection. The default value of index is WHOLE_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

    • isCollection

      public abstract boolean isCollection()
      Returns true if the value of the pointer is an array or a Collection.
      Returns:
      boolean

    • 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

    • getValue

      public Object getValue()
      By default, returns getNode(), can be overridden to return a "canonical" value, like for instance a DOM element should return its string value.
      Specified by:
      getValue in interface Pointer
      Returns:
      Object value

    • getValuePointer

      public NodePointer 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 override getValuePointer() directly. Override the getImmediateValuePointer() method instead. The getValuePointer() method is calls getImmediateValuePointer() and, if the result is not this, invokes getValuePointer() recursively. The idea here is to open all nested containers. Let's say we have a container within a container within a container. The getValuePointer() method should then open all those containers and return the pointer to the ultimate contents. It does so with the above recursion.
      Returns:
      NodePointer

    • getImmediateValuePointer

      public NodePointer getImmediateValuePointer()
      Returns:
      NodePointer is either this or a pointer for the immediately contained value.
      See Also:

    • 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

    • getName

      public abstract QName getName()
      Returns the name of this node. Can be null.
      Returns:
      QName

    • getBaseValue

      public abstract Object 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

    • getNodeValue

      public Object 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

    • getNode

      public Object 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.
      Specified by:
      getNode in interface Pointer
      Returns:
      Object node

    • getRootNode

      public Object getRootNode()
      Get the root node.
      Specified by:
      getRootNode in interface Pointer
      Returns:
      Object value of this pointer's root (top parent).

    • getImmediateNode

      public abstract Object getImmediateNode()
      Returns the object the pointer points to; does not convert it to a "canonical" type.
      Returns:
      Object node

    • setValue

      public abstract void setValue(Object value)
      Converts the value to the required type and changes the corresponding object to that value.
      Specified by:
      setValue in interface Pointer
      Parameters:
      value - the value to set

    • compareChildNodePointers

      public 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.
      Parameters:
      pointer1 - first pointer to be compared
      pointer2 - second pointer to be compared
      Returns:
      int per Java comparison conventions

    • testNode

      public boolean testNode(NodeTest test)
      Checks if this Pointer matches the supplied NodeTest.
      Parameters:
      test - the NodeTest to execute
      Returns:
      true if a match

    • equalStrings

      private static boolean equalStrings(String s1, String s2)
      Compare two strings, either of which may be null, for equality.
      Parameters:
      s1 - the first String to compare
      s2 - the second String to compare
      Returns:
      true if both Strings are null, same or equal

    • createPath

      public NodePointer createPath(JXPathContext context, Object value)
      Called directly by JXPathContext. Must create path and set value.
      Parameters:
      context - the owning JXPathContext
      value - the new value to set
      Returns:
      created NodePointer

    • remove

      public void remove()
      Remove the node of the object graph this pointer points to.

    • createPath

      public NodePointer createPath(JXPathContext context)
      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

    • createChild

      public NodePointer 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. This method may have to expand the collection in order to assign the element.
      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

    • createChild

      public 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. 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 JXPathCOntext
      name - the QName at which a child should be created
      index - child index.
      Returns:
      created NodePointer

    • createAttribute

      public NodePointer createAttribute(JXPathContext context, QName name)
      Called to create a non-existing attribute
      Parameters:
      context - the owning JXPathCOntext
      name - the QName at which an attribute should be created
      Returns:
      created NodePointer

    • getLocale

      public Locale 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

      public boolean isLanguage(String lang)
      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.

    • childIterator

      public 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.
      Parameters:
      test - NodeTest to filter children
      reverse - specified iteration direction
      startWith - the NodePointer to start with
      Returns:
      NodeIterator

    • attributeIterator

      public NodeIterator attributeIterator(QName qname)
      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

      public 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

      public NodePointer namespacePointer(String namespace)
      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

    • getNamespaceURI

      public String getNamespaceURI(String prefix)
      Decodes a namespace prefix to the corresponding URI.
      Parameters:
      prefix - prefix to decode
      Returns:
      String uri

    • getNamespaceURI

      public String getNamespaceURI()
      Returns the namespace URI associated with this Pointer.
      Returns:
      String uri

    • isDefaultNamespace

      protected boolean isDefaultNamespace(String prefix)
      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

    • getDefaultNamespaceURI

      protected String getDefaultNamespaceURI()
      Get the default ns uri
      Returns:
      String uri

    • getPointerByID

      public Pointer getPointerByID(JXPathContext context, String id)
      Locates a node by ID.
      Parameters:
      context - JXPathContext owning context
      id - String id
      Returns:
      Pointer found

    • getPointerByKey

      public Pointer getPointerByKey(JXPathContext context, String key, String value)
      Locates a node by key and value.
      Parameters:
      context - owning JXPathContext
      key - key to search for
      value - value to match
      Returns:
      Pointer found

    • getNodeSetByKey

      public NodeSet getNodeSetByKey(JXPathContext context, String key, Object value)
      Find a NodeSet by key/value.
      Parameters:
      context - owning JXPathContext
      key - key to search for
      value - value to match
      Returns:
      NodeSet found

    • asPath

      public String asPath()
      Returns an XPath that maps to this Pointer.
      Specified by:
      asPath in interface Pointer
      Returns:
      String xpath expression

    • clone

      public Object clone()
      Clone this NodePointer.
      Specified by:
      clone in interface Pointer
      Overrides:
      clone in class Object
      Returns:
      cloned NodePointer

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • compareTo

      public int compareTo(Object object)
      Specified by:
      compareTo in interface Comparable

    • compareNodePointers

      private int compareNodePointers(NodePointer p1, int depth1, NodePointer p2, int depth2)
      Compare node pointers.
      Parameters:
      p1 - pointer 1
      depth1 - depth 1
      p2 - pointer 2
      depth2 - depth 2
      Returns:
      comparison result: (invalid input: '<' 0) -> (p1 lt p2); (0) -> (p1 eq p2); (> 0) -> (p1 gt p2)

    • printPointerChain

      public void printPointerChain()
      Print internal structure of a pointer for debugging

    • escape

      protected String escape(String string)
      Return a string escaping single and double quotes.
      Parameters:
      string - string to treat
      Returns:
      string with any necessary changes made.

    • getAbstractFactory

      protected AbstractFactory getAbstractFactory(JXPathContext context)
      Get the AbstractFactory associated with the specified JXPathContext.
      Parameters:
      context - JXPathContext
      Returns:
      AbstractFactory

    • printDeep

      private static void printDeep(NodePointer pointer, String indent)
      Print deep
      Parameters:
      pointer - to print
      indent - indentation level