public NodeImpl() 
{

}

Constructor for serialization.

 protected NodeImpl(CoreDocumentImpl ownerDocument) 
{
    //
    // Constructors
    //
        // as long as we do not have any owner, ownerNode is our ownerDocument
        ownerNode = ownerDocument;
}

No public constructor; only subclasses of Node should be instantiated, and those normally via a Document's factory methods

Every Node knows what Document it belongs to.

 public  void addEventListener(String type,
    EventListener listener,
    boolean useCapture) 
{
        // simply forward to Document
        ownerDocument().addEventListener(this, type, listener, useCapture);
}

 public Node appendChild(Node newChild) throws DOMException 
{
    	return insertBefore(newChild, null);
}

Adds a child node to the end of the list of children for this node. Convenience shorthand for insertBefore(newChild,null).

 protected  void changed() 
{
        // we do not actually store this information on every node, we only
        // have a global indicator on the Document. Doing otherwise cost us too
        // much for little gain.
        ownerDocument().changed();
}

Denotes that this node has changed.

 protected int changes() 
{
        // we do not actually store this information on every node, we only
        // have a global indicator on the Document. Doing otherwise cost us too
        // much for little gain.
        return ownerDocument().changes();
}

Returns the number of changes to this node.

 public Node cloneNode(boolean deep) 
{
        if (needsSyncData()) {
            synchronizeData();
	}
    	NodeImpl newnode;
    	try {
            newnode = (NodeImpl)clone();
    	}
    	catch (CloneNotSupportedException e) {
            // if we get here we have an error in our program we may as well
            // be vocal about it, so that people can take appropriate action.
            throw new RuntimeException("**Internal Error**" + e);
    	}
        // Need to break the association w/ original kids
    	newnode.ownerNode      = ownerDocument();
        newnode.isOwned(false);
        // By default we make all clones readwrite,
        // this is overriden in readonly subclasses
        newnode.isReadOnly(false);
        ownerDocument().callUserDataHandlers(this, newnode,
                                             UserDataHandler.NODE_CLONED);
    	return newnode;
}

Returns a duplicate of a given node. You can consider this a generic "copy constructor" for nodes. The newly returned object should be completely independent of the source object's subtree, so changes in one after the clone has been made will not affect the other.

Note: since we never have any children deep is meaningless here, ParentNode overrides this behavior.

 public short compareDocumentPosition(Node other) throws DOMException 
{
        // If the nodes are the same, no flags should be set
        if (this==other) 
          return 0; 
        // check if other is from a different implementation
        if (other != null && !(other instanceof NodeImpl)) {
            // other comes from a different implementation
            String msg = DOMMessageFormatter.formatMessage(
               DOMMessageFormatter.DOM_DOMAIN, "NOT_SUPPORTED_ERR", null);
            throw new DOMException(DOMException.NOT_SUPPORTED_ERR, msg);
        }
        Document thisOwnerDoc, otherOwnerDoc;
        // get the respective Document owners.  
        if (this.getNodeType() == Node.DOCUMENT_NODE) 
          thisOwnerDoc = (Document)this;
        else
          thisOwnerDoc = this.getOwnerDocument();
        if (other.getNodeType() == Node.DOCUMENT_NODE) 
          otherOwnerDoc = (Document)other;
        else
          otherOwnerDoc = other.getOwnerDocument();
        // If from different documents, we know they are disconnected. 
        // and have an implementation dependent order 
        if (thisOwnerDoc != otherOwnerDoc && 
            thisOwnerDoc !=null && 
            otherOwnerDoc !=null) 
 {
          int otherDocNum = ((CoreDocumentImpl)otherOwnerDoc).getNodeNumber();
          int thisDocNum = ((CoreDocumentImpl)thisOwnerDoc).getNodeNumber();
          if (otherDocNum  > thisDocNum)  
            return DOCUMENT_POSITION_DISCONNECTED | 
                   DOCUMENT_POSITION_FOLLOWING | 
                   DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC;
          else
            return DOCUMENT_POSITION_DISCONNECTED | 
                   DOCUMENT_POSITION_PRECEDING | 
                   DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC;
        }
        // Find the ancestor of each node, and the distance each node is from 
        // its ancestor.
        // During this traversal, look for ancestor/descendent relationships 
        // between the 2 nodes in question. 
        // We do this now, so that we get this info correct for attribute nodes 
        // and their children. 
        Node node; 
        Node thisAncestor = this;
        Node otherAncestor = other;
        int thisDepth=0;
        int otherDepth=0;
        for (node=this; node != null; node = node.getParentNode()) {
            thisDepth +=1;
            if (node == other) 
              // The other node is an ancestor of this one.
              return (DOCUMENT_POSITION_CONTAINS | 
                      DOCUMENT_POSITION_PRECEDING);
            thisAncestor = node;
        }
        for (node=other; node!=null; node=node.getParentNode()) {
            otherDepth +=1;
            if (node == this) 
              // The other node is a descendent of the reference node.
              return (DOCUMENT_POSITION_IS_CONTAINED | 
                      DOCUMENT_POSITION_FOLLOWING);
            otherAncestor = node;
        }
        int thisAncestorType = thisAncestor.getNodeType();
        int otherAncestorType = otherAncestor.getNodeType();
        Node thisNode = this;
        Node otherNode = other;
        // Special casing for ENTITY, NOTATION, DOCTYPE and ATTRIBUTES
        // LM:  should rewrite this.                                          
        switch (thisAncestorType) {
          case Node.NOTATION_NODE:
          case Node.ENTITY_NODE: {
            DocumentType container = thisOwnerDoc.getDoctype();
            if (container == otherAncestor) return 
                   (DOCUMENT_POSITION_CONTAINS | DOCUMENT_POSITION_PRECEDING);
            switch (otherAncestorType) {
              case Node.NOTATION_NODE: 
              case Node.ENTITY_NODE:  {
                if (thisAncestorType != otherAncestorType) 
                 // the nodes are of different types
                 return ((thisAncestorType >otherAncestorType) ? 
                    DOCUMENT_POSITION_PRECEDING:DOCUMENT_POSITION_FOLLOWING);
                else {
                 // the nodes are of the same type.  Find order.
                 if (thisAncestorType == Node.NOTATION_NODE)
                     if (((NamedNodeMapImpl)container.getNotations()).precedes(otherAncestor,thisAncestor))
                       return (DOCUMENT_POSITION_PRECEDING | 
                               DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC);
                     else
                       return (DOCUMENT_POSITION_FOLLOWING | 
                               DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC);
                 else
                     if (((NamedNodeMapImpl)container.getEntities()).precedes(otherAncestor,thisAncestor))
                       return (DOCUMENT_POSITION_PRECEDING | 
                               DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC);
                     else
                       return (DOCUMENT_POSITION_FOLLOWING | 
                               DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC);
                }
              }
            }
            thisNode = thisAncestor = thisOwnerDoc;
            break;
          } 
          case Node.DOCUMENT_TYPE_NODE: {
            if (otherNode == thisOwnerDoc) 
              return (DOCUMENT_POSITION_PRECEDING | 
                      DOCUMENT_POSITION_CONTAINS);
            else if (thisOwnerDoc!=null && thisOwnerDoc==otherOwnerDoc)
              return (DOCUMENT_POSITION_FOLLOWING);
            break;
          }
          case Node.ATTRIBUTE_NODE: {
            thisNode = ((AttrImpl)thisAncestor).getOwnerElement();
            if (otherAncestorType==Node.ATTRIBUTE_NODE) {
              otherNode = ((AttrImpl)otherAncestor).getOwnerElement();
              if (otherNode == thisNode) {
                if (((NamedNodeMapImpl)thisNode.getAttributes()).precedes(other,this))
                  return (DOCUMENT_POSITION_PRECEDING | 
                          DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC);
                else
                  return (DOCUMENT_POSITION_FOLLOWING | 
                          DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC);
              }
            }
            // Now, find the ancestor of the element
            thisDepth=0;
            for (node=thisNode; node != null; node=node.getParentNode()) {
                thisDepth +=1;
                if (node == otherNode) 
                  {
                  // The other node is an ancestor of the owning element
                  return (DOCUMENT_POSITION_CONTAINS | 
                          DOCUMENT_POSITION_PRECEDING);
                  }
                thisAncestor = node;
            }
          }
        }
        switch (otherAncestorType) {
          case Node.NOTATION_NODE:
          case Node.ENTITY_NODE: {
          DocumentType container = thisOwnerDoc.getDoctype();
            if (container == this) return (DOCUMENT_POSITION_IS_CONTAINED | 
                                          DOCUMENT_POSITION_FOLLOWING);
            otherNode = otherAncestor = thisOwnerDoc;
            break;
          }
          case Node.DOCUMENT_TYPE_NODE: {
            if (thisNode == otherOwnerDoc) 
              return (DOCUMENT_POSITION_FOLLOWING | 
                      DOCUMENT_POSITION_IS_CONTAINED);
            else if (otherOwnerDoc!=null && thisOwnerDoc==otherOwnerDoc)
              return (DOCUMENT_POSITION_PRECEDING);
            break;
          }
          case Node.ATTRIBUTE_NODE: {
            otherDepth=0;
            otherNode = ((AttrImpl)otherAncestor).getOwnerElement();
            for (node=otherNode; node != null; node=node.getParentNode()) {
                otherDepth +=1;
                if (node == thisNode) 
                  // The other node is a descendent of the reference 
                  // node's element
                  return DOCUMENT_POSITION_FOLLOWING | 
                         DOCUMENT_POSITION_IS_CONTAINED;
                otherAncestor = node;
            }
          }
        }
        // thisAncestor and otherAncestor must be the same at this point,  
        // otherwise, the original nodes are disconnected 
        if (thisAncestor != otherAncestor) {
          int thisAncestorNum, otherAncestorNum;
          thisAncestorNum = ((NodeImpl)thisAncestor).getNodeNumber();
          otherAncestorNum = ((NodeImpl)otherAncestor).getNodeNumber();
          if (thisAncestorNum  > otherAncestorNum) 
            return DOCUMENT_POSITION_DISCONNECTED | 
                   DOCUMENT_POSITION_FOLLOWING | 
                   DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC;
          else
            return DOCUMENT_POSITION_DISCONNECTED | 
                   DOCUMENT_POSITION_PRECEDING | 
                   DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC;
        }
        // Go up the parent chain of the deeper node, until we find a node 
        // with the same depth as the shallower node
        if (thisDepth  > otherDepth) {
          for (int i=0; i< thisDepth - otherDepth; i++)
            thisNode = thisNode.getParentNode();
          // Check if the node we have reached is in fact "otherNode". This can
          // happen in the case of attributes.  In this case, otherNode 
          // "precedes" this.
          if (thisNode == otherNode) 
{
            return DOCUMENT_POSITION_PRECEDING;
          }
        }
        else {
          for (int i=0; i< otherDepth - thisDepth; i++)
            otherNode = otherNode.getParentNode();
          // Check if the node we have reached is in fact "thisNode".  This can
          // happen in the case of attributes.  In this case, otherNode 
          // "follows" this.
          if (otherNode == thisNode) 
            return DOCUMENT_POSITION_FOLLOWING;
        }
        // We now have nodes at the same depth in the tree.  Find a common 
        // ancestor.                                   
        Node thisNodeP, otherNodeP;
        for (thisNodeP=thisNode.getParentNode(),
                  otherNodeP=otherNode.getParentNode();
             thisNodeP!=otherNodeP;) {
             thisNode = thisNodeP;
             otherNode = otherNodeP;
             thisNodeP = thisNodeP.getParentNode();
             otherNodeP = otherNodeP.getParentNode();
        }
        // At this point, thisNode and otherNode are direct children of 
        // the common ancestor.  
        // See whether thisNode or otherNode is the leftmost
        for (Node current=thisNodeP.getFirstChild(); 
                  current!=null;
                  current=current.getNextSibling()) {
               if (current==otherNode) {
                 return DOCUMENT_POSITION_PRECEDING;
               }
               else if (current==thisNode) {
                 return DOCUMENT_POSITION_FOLLOWING;
               }
        }
        // REVISIT:  shouldn't get here.   Should probably throw an 
        // exception
        return 0;
}

Compares a node with this node with regard to their position in the document.

 public short compareTreePosition(Node other) 
{
        // Questions of clarification for this method - to be answered by the
        // DOM WG.   Current assumptions listed - LM
        // 
        // 1. How do ENTITY nodes compare?  
        //    Current assumption: TREE_POSITION_DISCONNECTED, as ENTITY nodes 
        //    aren't really 'in the tree'
        //
        // 2. How do NOTATION nodes compare?
        //    Current assumption: TREE_POSITION_DISCONNECTED, as NOTATION nodes
        //    aren't really 'in the tree'
        //
        // 3. Are TREE_POSITION_ANCESTOR and TREE_POSITION_DESCENDANT     
        //    only relevant for nodes that are "part of the document tree"?   
        //     < outer >
        //         < inner  myattr="true"/ >
        //     < /outer >
        //    Is the element node "outer" considered an ancestor of "myattr"?
        //    Current assumption: No.                                     
        //
        // 4. How do children of ATTRIBUTE nodes compare (with eachother, or  
        //    with children of other attribute nodes with the same element)    
        //    Current assumption: Children of ATTRIBUTE nodes are treated as if 
        //    they they are the attribute node itself, unless the 2 nodes 
        //    are both children of the same attribute. 
        //
        // 5. How does an ENTITY_REFERENCE node compare with it's children? 
        //    Given the DOM, it should precede its children as an ancestor. 
        //    Given "document order",  does it represent the same position?     
        //    Current assumption: An ENTITY_REFERENCE node is an ancestor of its
        //    children.
        //
        // 6. How do children of a DocumentFragment compare?   
        //    Current assumption: If both nodes are part of the same document 
        //    fragment, there are compared as if they were part of a document. 
        // If the nodes are the same...
        if (this==other) 
          return (TREE_POSITION_SAME_NODE | TREE_POSITION_EQUIVALENT);
        // If either node is of type ENTITY or NOTATION, compare as disconnected
        short thisType = this.getNodeType();
        short otherType = other.getNodeType();
        // If either node is of type ENTITY or NOTATION, compare as disconnected
        if (thisType == Node.ENTITY_NODE || 
            thisType == Node.NOTATION_NODE ||
            otherType == Node.ENTITY_NODE ||
            otherType == Node.NOTATION_NODE ) {
          return TREE_POSITION_DISCONNECTED; 
        }
        // Find the ancestor of each node, and the distance each node is from 
        // its ancestor.
        // During this traversal, look for ancestor/descendent relationships 
        // between the 2 nodes in question. 
        // We do this now, so that we get this info correct for attribute nodes 
        // and their children. 
        Node node; 
        Node thisAncestor = this;
        Node otherAncestor = other;
        int thisDepth=0;
        int otherDepth=0;
        for (node=this; node != null; node = node.getParentNode()) {
            thisDepth +=1;
            if (node == other) 
              // The other node is an ancestor of this one.
              return (TREE_POSITION_ANCESTOR | TREE_POSITION_PRECEDING);
            thisAncestor = node;
        }
        for (node=other; node!=null; node=node.getParentNode()) {
            otherDepth +=1;
            if (node == this) 
              // The other node is a descendent of the reference node.
              return (TREE_POSITION_DESCENDANT | TREE_POSITION_FOLLOWING);
            otherAncestor = node;
        }
        Node thisNode = this;
        Node otherNode = other;
        int thisAncestorType = thisAncestor.getNodeType();
        int otherAncestorType = otherAncestor.getNodeType();
        // if the ancestor is an attribute, get owning element. 
        // we are now interested in the owner to determine position.
        if (thisAncestorType == Node.ATTRIBUTE_NODE)  {
           thisNode = ((AttrImpl)thisAncestor).getOwnerElement();
        }
        if (otherAncestorType == Node.ATTRIBUTE_NODE) {
           otherNode = ((AttrImpl)otherAncestor).getOwnerElement();
        }
        // Before proceeding, we should check if both ancestor nodes turned
        // out to be attributes for the same element
        if (thisAncestorType == Node.ATTRIBUTE_NODE &&  
            otherAncestorType == Node.ATTRIBUTE_NODE &&  
            thisNode==otherNode)              
            return TREE_POSITION_EQUIVALENT;
        // Now, find the ancestor of the owning element, if the original
        // ancestor was an attribute
        // Note:  the following 2 loops are quite close to the ones above.
        // May want to common them up.  LM.
        if (thisAncestorType == Node.ATTRIBUTE_NODE) {
            thisDepth=0;
            for (node=thisNode; node != null; node=node.getParentNode()) {
                thisDepth +=1;
                if (node == otherNode) 
                  // The other node is an ancestor of the owning element
                  {
                  return TREE_POSITION_PRECEDING;
                  }
                thisAncestor = node;
            }
        }
        // Now, find the ancestor of the owning element, if the original
        // ancestor was an attribute
        if (otherAncestorType == Node.ATTRIBUTE_NODE) {
            otherDepth=0;
            for (node=otherNode; node != null; node=node.getParentNode()) {
                otherDepth +=1;
                if (node == thisNode) 
                  // The other node is a descendent of the reference 
                  // node's element
                  return TREE_POSITION_FOLLOWING;
                otherAncestor = node;
            }
        }
        // thisAncestor and otherAncestor must be the same at this point,  
        // otherwise, we are not in the same tree or document fragment
        if (thisAncestor != otherAncestor) 
          return TREE_POSITION_DISCONNECTED; 
        // Go up the parent chain of the deeper node, until we find a node 
        // with the same depth as the shallower node
        if (thisDepth  > otherDepth) {
          for (int i=0; i< thisDepth - otherDepth; i++)
            thisNode = thisNode.getParentNode();
          // Check if the node we have reached is in fact "otherNode". This can
          // happen in the case of attributes.  In this case, otherNode 
          // "precedes" this.
          if (thisNode == otherNode) 
            return TREE_POSITION_PRECEDING;
        }
        else {
          for (int i=0; i< otherDepth - thisDepth; i++)
            otherNode = otherNode.getParentNode();
          // Check if the node we have reached is in fact "thisNode".  This can
          // happen in the case of attributes.  In this case, otherNode 
          // "follows" this.
          if (otherNode == thisNode) 
            return TREE_POSITION_FOLLOWING;
        }
        // We now have nodes at the same depth in the tree.  Find a common 
        // ancestor.                                   
        Node thisNodeP, otherNodeP;
        for (thisNodeP=thisNode.getParentNode(),
                  otherNodeP=otherNode.getParentNode();
             thisNodeP!=otherNodeP;) {
             thisNode = thisNodeP;
             otherNode = otherNodeP;
             thisNodeP = thisNodeP.getParentNode();
             otherNodeP = otherNodeP.getParentNode();
        }
        // At this point, thisNode and otherNode are direct children of 
        // the common ancestor.  
        // See whether thisNode or otherNode is the leftmost
        for (Node current=thisNodeP.getFirstChild(); 
                  current!=null;
                  current=current.getNextSibling()) {
               if (current==otherNode) {
                 return TREE_POSITION_PRECEDING;
               }
               else if (current==thisNode) {
                 return TREE_POSITION_FOLLOWING;
               }
        }
        // REVISIT:  shouldn't get here.   Should probably throw an 
        // exception
        return 0;
}

Compares a node with this node with regard to their position in the tree and according to the document order. This order can be extended by module that define additional types of nodes.

 public boolean dispatchEvent(Event event) 
{
        // simply forward to Document
        return ownerDocument().dispatchEvent(this, event);
}

 public NamedNodeMap getAttributes() 
{
    	return null; // overridden in ElementImpl
}

Return the collection of attributes associated with this node, or null if none. At this writing, Element is the only type of node which will ever have attributes.

 public String getBaseURI() 
{
        return null;
}

The absolute base URI of this node or null if undefined. This value is computed according to . However, when the Document supports the feature "HTML" , the base URI is computed using first the value of the href attribute of the HTML BASE element if any, and the value of the documentURI attribute from the Document interface otherwise.
When the node is an Element, a Document or a a ProcessingInstruction, this attribute represents the properties [base URI] defined in . When the node is a Notation, an Entity, or an EntityReference, this attribute represents the properties [declaration base URI] in the . How will this be affected by resolution of relative namespace URIs issue?It's not.Should this only be on Document, Element, ProcessingInstruction, Entity, and Notation nodes, according to the infoset? If not, what is it equal to on other nodes? Null? An empty string? I think it should be the parent's.No.Should this be read-only and computed or and actual read-write attribute?Read-only and computed (F2F 19 Jun 2000 and teleconference 30 May 2001).If the base HTML element is not yet attached to a document, does the insert change the Document.baseURI? Yes. (F2F 26 Sep 2001)

 public NodeList getChildNodes() 
{
        return this;
}

Obtain a NodeList enumerating all children of this node. If there are none, an (initially) empty NodeList is returned.

NodeLists are "live"; as children are added/removed the NodeList will immediately reflect those changes. Also, the NodeList refers to the actual nodes, so changes to those nodes made via the DOM tree will be reflected in the NodeList and vice versa.

In this implementation, Nodes implement the NodeList interface and provide their own getChildNodes() support. Other DOMs may solve this differently.

 protected Node getContainer() 
{
       return null;
}

For non-child nodes, the node which "points" to this node. For example, the owning element for an attribute

 Node getElementAncestor(Node currentNode) 
{
        Node parent = currentNode.getParentNode();
        if (parent != null) {
            short type = parent.getNodeType();
            if (type == Node.ELEMENT_NODE) {
                return parent;
            }
            return getElementAncestor(parent);
        }
        return null;
}

 public Object getFeature(String feature,
    String version) 
{
        // we don't have any alternate node, either this node does the job
        // or we don't have anything that does
        return isSupported(feature, version) ? this : null;
}

 public Node getFirstChild() 
{
    	return null;
}

The first child of this Node, or null if none.

By default we do not have any children, ParentNode overrides this.

 public Node getLastChild() 
{
	return null;
}

The first child of this Node, or null if none.

By default we do not have any children, ParentNode overrides this.

 public int getLength() 
{
	return 0;
}

NodeList method: Count the immediate children of this node

By default we do not have any children, ParentNode overrides this.

 public String getLocalName() 
{
        return null;
}

Introduced in DOM Level 2.

Returns the local part of the qualified name of this node. For nodes created with a DOM Level 1 method, such as createElement from the Document interface, and for nodes of any type other than ELEMENT_NODE and ATTRIBUTE_NODE this is the same as the nodeName attribute.

 public String getNamespaceURI() 
{
        return null;
}

Introduced in DOM Level 2.

The namespace URI of this node, or null if it is unspecified. When this node is of any type other than ELEMENT_NODE and ATTRIBUTE_NODE, this is always null and setting it has no effect.

This is not a computed value that is the result of a namespace lookup based on an examination of the namespace declarations in scope. It is merely the namespace URI given at creation time.

For nodes created with a DOM Level 1 method, such as createElement from the Document interface, this is null.

 public Node getNextSibling() 
{
        return null;            // default behavior, overriden in ChildNode
}

The next child of this node's parent, or null if none

 abstract public String getNodeName()
the name of this node.

 protected int getNodeNumber() 
{
        int nodeNumber;
        CoreDocumentImpl cd = (CoreDocumentImpl)(this.getOwnerDocument());
        nodeNumber = cd.getNodeNumber(this);   
        return nodeNumber;
}

Returns the node number

 abstract public short getNodeType()
A short integer indicating what type of node this is. The named
constants for this value are defined in the org.w3c.dom.Node interface.

 public String getNodeValue() throws DOMException 
{
        return null;            // overridden in some subclasses
}

Returns the node value.

 public Document getOwnerDocument() 
{
        // if we have an owner simply forward the request
        // otherwise ownerNode is our ownerDocument
        if (isOwned()) {
            return ownerNode.ownerDocument();
        } else {
            return (Document) ownerNode;
        }
}

Find the Document that this Node belongs to (the document in whose context the Node was created). The Node may or may not currently be part of that Document's actual contents.

 public Node getParentNode() 
{
        return null;            // overriden by ChildNode
}

Obtain the DOM-tree parent of this node, or null if it is not currently active in the DOM tree (perhaps because it has just been created or removed). Note that Document, DocumentFragment, and Attribute will never have parents.

 public String getPrefix() 
{
        return null;
}

Introduced in DOM Level 2.

The namespace prefix of this node, or null if it is unspecified. When this node is of any type other than ELEMENT_NODE and ATTRIBUTE_NODE this is always null and setting it has no effect.

For nodes created with a DOM Level 1 method, such as createElement from the Document interface, this is null.

 public Node getPreviousSibling() 
{
        return null;            // default behavior, overriden in ChildNode
}

The previous child of this node's parent, or null if none

 public boolean getReadOnly() 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        return isReadOnly();
}

NON-DOM: Returns true if this node is read-only. This is a shallow check.

 public String getTextContent() throws DOMException 
{
        return getNodeValue();  // overriden in some subclasses
}

This attribute returns the text content of this node and its descendants. When it is defined to be null, setting it has no effect. When set, any possible children this node may have are removed and replaced by a single Text node containing the string this attribute is set to. On getting, no serialization is performed, the returned string does not contain any markup. No whitespace normalization is performed, the returned string does not contain the element content whitespaces . Similarly, on setting, no parsing is performed either, the input string is taken as pure textual content.
The string returned is made of the text content of this node depending on its type, as defined below: /** This attribute returns the text content of this node and its descendants. When it is defined to be null, setting it has no effect. When set, any possible children this node may have are removed and replaced by a single Text node containing the string this attribute is set to. On getting, no serialization is performed, the returned string does not contain any markup. No whitespace normalization is performed, the returned string does not contain the element content whitespaces . Similarly, on setting, no parsing is performed either, the input string is taken as pure textual content.
The string returned is made of the text content of this node depending on its type, as defined below:

Node type	Content

Node type	Content
ELEMENT_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE, DOCUMENT_FRAGMENT_NODE	concatenation of the textContent attribute value of every child node, excluding COMMENT_NODE and PROCESSING_INSTRUCTION_NODE nodes
ATTRIBUTE_NODE, TEXT_NODE, CDATA_SECTION_NODE, COMMENT_NODE, PROCESSING_INSTRUCTION_NODE	nodeValue
DOCUMENT_NODE, DOCUMENT_TYPE_NODE, NOTATION_NODE	null

  void getTextContent(StringBuffer buf) throws DOMException 
{
        String content = getNodeValue();
        if (content != null) {
            buf.append(content);
        }
}

 public Object getUserData() 
{
        return ownerDocument().getUserData(this);
}

NON-DOM: Returns the user data associated to this node.

 public Object getUserData(String key) 
{
        return ownerDocument().getUserData(this, key);
}

Retrieves the object associated to a key on a this node. The object must first have been set to this node by calling setUserData with the same key.

 protected Hashtable getUserDataRecord() 
{
        return ownerDocument().getUserDataRecord(this);
}

 public boolean hasAttributes() 
{
        return false;           // overridden in ElementImpl
}

Returns whether this node (if it is an element) has any attributes.

 public boolean hasChildNodes() 
{
        return false;
}

Test whether this node has any children. Convenience shorthand for (Node.getFirstChild()!=null)

By default we do not have any children, ParentNode overrides this.

 final boolean hasStringValue() 
{
        return (flags & HASSTRING) != 0;
}

 final  void hasStringValue(boolean value) 
{
        flags = (short) (value ? flags | HASSTRING : flags & ~HASSTRING);
}

 public Node insertBefore(Node newChild,
    Node refChild) throws DOMException 
{
	throw new DOMException(DOMException.HIERARCHY_REQUEST_ERR, 
              DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN,
                 "HIERARCHY_REQUEST_ERR", null));
}

Move one or more node(s) to our list of children. Note that this implicitly removes them from their previous parent.

By default we do not accept any children, ParentNode overrides this.

 final boolean internalIsIgnorableWhitespace() 
{
        return (flags & IGNORABLEWS) != 0;
}

 public boolean isDefaultNamespace(String namespaceURI) 
{
        // REVISIT: remove casts when DOM L3 becomes REC.
        short type = this.getNodeType();
        switch (type) {
        case Node.ELEMENT_NODE: {             
            String namespace = this.getNamespaceURI();
            String prefix = this.getPrefix();
            // REVISIT: is it possible that prefix is empty string?
            if (prefix == null || prefix.length() == 0) {
                if (namespaceURI == null) {
                    return (namespace == namespaceURI);
                }
                return namespaceURI.equals(namespace);
            }
            if (this.hasAttributes()) {
                ElementImpl elem = (ElementImpl)this;
                NodeImpl attr = (NodeImpl)elem.getAttributeNodeNS("http://www.w3.org/2000/xmlns/", "xmlns");
                if (attr != null) {
                    String value = attr.getNodeValue();
                    if (namespaceURI == null) {
                        return (namespace == value);
                    }
                    return namespaceURI.equals(value);
                }
            }
            NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
            if (ancestor != null) {
                return ancestor.isDefaultNamespace(namespaceURI);
            }
            return false;
        }
        case Node.DOCUMENT_NODE:{
                return((NodeImpl)((Document)this).getDocumentElement()).isDefaultNamespace(namespaceURI);
            }
        case Node.ENTITY_NODE :
        case Node.NOTATION_NODE:
        case Node.DOCUMENT_FRAGMENT_NODE:
        case Node.DOCUMENT_TYPE_NODE:
            // type is unknown
            return false;
        case Node.ATTRIBUTE_NODE:{
                if (this.ownerNode.getNodeType() == Node.ELEMENT_NODE) {
                    return ownerNode.isDefaultNamespace(namespaceURI);
                }
                return false;
            }
        default:{   
                NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
                if (ancestor != null) {
                    return ancestor.isDefaultNamespace(namespaceURI);
                }
                return false;
            }
        }
}

DOM Level 3: Experimental This method checks if the specified namespaceURI is the default namespace or not.

 public boolean isEqualNode(Node arg) 
{
        if (arg == this) {
            return true;
        }
        if (arg.getNodeType() != getNodeType()) {
            return false;
        }
        // in theory nodeName can't be null but better be careful
        // who knows what other implementations may be doing?...
        if (getNodeName() == null) {
            if (arg.getNodeName() != null) {
                return false;
            }
        }
        else if (!getNodeName().equals(arg.getNodeName())) {
            return false;
        }
        if (getLocalName() == null) {
            if (arg.getLocalName() != null) {
                return false;
            }
        }
        else if (!getLocalName().equals(arg.getLocalName())) {
            return false;
        }
        if (getNamespaceURI() == null) {
            if (arg.getNamespaceURI() != null) {
                return false;
            }
        }
        else if (!getNamespaceURI().equals(arg.getNamespaceURI())) {
            return false;
        }
        if (getPrefix() == null) {
            if (arg.getPrefix() != null) {
                return false;
            }
        }
        else if (!getPrefix().equals(arg.getPrefix())) {
            return false;
        }
        if (getNodeValue() == null) {
            if (arg.getNodeValue() != null) {
                return false;
            }
        }
        else if (!getNodeValue().equals(arg.getNodeValue())) {
            return false;
        }
        return true;
}

Tests whether two nodes are equal.
This method tests for equality of nodes, not sameness (i.e., whether the two nodes are references to the same object) which can be tested with Node.isSameNode. All nodes that are the same will also be equal, though the reverse may not be true.
Two nodes are equal if and only if the following conditions are satisfied: The two nodes are of the same type.The following string attributes are equal: nodeName, localName, namespaceURI, prefix, nodeValue , baseURI. This is: they are both null, or they have the same length and are character for character identical. The attributes NamedNodeMaps are equal. This is: they are both null, or they have the same length and for each node that exists in one map there is a node that exists in the other map and is equal, although not necessarily at the same index.The childNodes NodeLists are equal. This is: they are both null, or they have the same length and contain equal nodes at the same index. This is true for Attr nodes as for any other type of node. Note that normalization can affect equality; to avoid this, nodes should be normalized before being compared.
For two DocumentType nodes to be equal, the following conditions must also be satisfied: The following string attributes are equal: publicId, systemId, internalSubset.The entities NamedNodeMaps are equal.The notations NamedNodeMaps are equal.
On the other hand, the following do not affect equality: the ownerDocument attribute, the specified attribute for Attr nodes, the isWhitespaceInElementContent attribute for Text nodes, as well as any user data or event listeners registered on the nodes.

 final boolean isFirstChild() 
{
        return (flags & FIRSTCHILD) != 0;
}

 final  void isFirstChild(boolean value) 
{
        flags = (short) (value ? flags | FIRSTCHILD : flags & ~FIRSTCHILD);
}

 final boolean isIdAttribute() 
{
        return (flags & ID) != 0;
}

 final  void isIdAttribute(boolean value) 
{
        flags = (short) (value ? flags | ID : flags & ~ID);
}

 final  void isIgnorableWhitespace(boolean value) 
{
        flags = (short) (value ? flags | IGNORABLEWS : flags & ~IGNORABLEWS);
}

 final boolean isNormalized() 
{
        return (flags & NORMALIZED) != 0;
}

 final  void isNormalized(boolean value) 
{
        // See if flag should propagate to parent.
        if (!value && isNormalized() && ownerNode != null) {
            ownerNode.isNormalized(false);
        }
        flags = (short) (value ?  flags | NORMALIZED : flags & ~NORMALIZED);
}

 final boolean isOwned() 
{
        return (flags & OWNED) != 0;
}

 final  void isOwned(boolean value) 
{
        flags = (short) (value ? flags | OWNED : flags & ~OWNED);
}

 final boolean isReadOnly() 
{
        return (flags & READONLY) != 0;
}

 final  void isReadOnly(boolean value) 
{
        flags = (short) (value ? flags | READONLY : flags & ~READONLY);
}

 public boolean isSameNode(Node other) 
{
        // we do not use any wrapper so the answer is obvious
        return this == other;
}

Returns whether this node is the same node as the given one.
This method provides a way to determine whether two Node references returned by the implementation reference the same object. When two Node references are references to the same object, even if through a proxy, the references may be used completely interchangably, such that all attributes have the same values and calling the same DOM method on either reference always has exactly the same effect.

 final boolean isSpecified() 
{
        return (flags & SPECIFIED) != 0;
}

 final  void isSpecified(boolean value) 
{
        flags = (short) (value ? flags | SPECIFIED : flags & ~SPECIFIED);
}

 public boolean isSupported(String feature,
    String version) 
{
        return ownerDocument().getImplementation().hasFeature(feature,
                                                              version);
}

Introduced in DOM Level 2.

Tests whether the DOM implementation implements a specific feature and that feature is supported by this node.

 public Node item(int index) 
{
	return null;
}

NodeList method: Return the Nth immediate child of this node, or null if the index is out of bounds.

By default we do not have any children, ParentNode overrides this.

 String lookupNamespacePrefix(String namespaceURI,
    ElementImpl el) 
{
        String namespace = this.getNamespaceURI();
        // REVISIT: if no prefix is available is it null or empty string, or 
        //          could be both?
        String prefix = this.getPrefix();
        if (namespace!=null && namespace.equals(namespaceURI)) {
            if (prefix != null) {
                String foundNamespace =  el.lookupNamespaceURI(prefix);
                if (foundNamespace !=null && foundNamespace.equals(namespaceURI)) {
                    return prefix;
                }
            }
        }
        if (this.hasAttributes()) {
            NamedNodeMap map = this.getAttributes();
            int length = map.getLength();
            for (int i=0;i< length;i++) {
                Node attr = map.item(i);
                String attrPrefix = attr.getPrefix();
                String value = attr.getNodeValue();
                namespace = attr.getNamespaceURI();
                if (namespace !=null && namespace.equals("http://www.w3.org/2000/xmlns/")) {
                    // DOM Level 2 nodes
                    if (((attr.getNodeName().equals("xmlns")) ||
                         (attrPrefix !=null && attrPrefix.equals("xmlns")) &&
                         value.equals(namespaceURI))) {
                        String localname= attr.getLocalName();
                        String foundNamespace = el.lookupNamespaceURI(localname);
                        if (foundNamespace !=null && foundNamespace.equals(namespaceURI)) {
                            return localname;
                        }
                    }
                }
            }
        }
        NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
        if (ancestor != null) {
            return ancestor.lookupNamespacePrefix(namespaceURI, el);
        }
        return null;
}

 public String lookupNamespaceURI(String specifiedPrefix) 
{
        short type = this.getNodeType();
        switch (type) {
        case Node.ELEMENT_NODE : {  
                String namespace = this.getNamespaceURI();
                String prefix = this.getPrefix();
                if (namespace !=null) {
                    // REVISIT: is it possible that prefix is empty string?
                    if (specifiedPrefix== null && prefix==specifiedPrefix) {
                        // looking for default namespace
                        return namespace;
                    } else if (prefix != null && prefix.equals(specifiedPrefix)) {
                        // non default namespace
                        return namespace;
                    }
                } 
                if (this.hasAttributes()) {
                    NamedNodeMap map = this.getAttributes();
                    int length = map.getLength();
                    for (int i=0;i< length;i++) {
                        Node attr = map.item(i);
                        String attrPrefix = attr.getPrefix();
                        String value = attr.getNodeValue();
                        namespace = attr.getNamespaceURI();
                        if (namespace !=null && namespace.equals("http://www.w3.org/2000/xmlns/")) {
                            // at this point we are dealing with DOM Level 2 nodes only
                            if (specifiedPrefix == null &&
                                attr.getNodeName().equals("xmlns")) {
                                // default namespace
                                return value;
                            } else if (attrPrefix !=null && 
                                       attrPrefix.equals("xmlns") &&
                                       attr.getLocalName().equals(specifiedPrefix)) {
                                // non default namespace
                                return value;
                            }
                        }
                    }
                }
                NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
                if (ancestor != null) {
                    return ancestor.lookupNamespaceURI(specifiedPrefix);
                }
                return null;
            }
        case Node.DOCUMENT_NODE : {   
                return((NodeImpl)((Document)this).getDocumentElement()).lookupNamespaceURI(specifiedPrefix);
            }
        case Node.ENTITY_NODE :
        case Node.NOTATION_NODE:
        case Node.DOCUMENT_FRAGMENT_NODE:
        case Node.DOCUMENT_TYPE_NODE:
            // type is unknown
            return null;
        case Node.ATTRIBUTE_NODE:{
                if (this.ownerNode.getNodeType() == Node.ELEMENT_NODE) {
                    return ownerNode.lookupNamespaceURI(specifiedPrefix);
                }
                return null;
            }
        default:{ 
                NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
                if (ancestor != null) {
                    return ancestor.lookupNamespaceURI(specifiedPrefix);
                }
                return null;
            }
        }
}

DOM Level 3 - Experimental: Look up the namespace URI associated to the given prefix, starting from this node. Use lookupNamespaceURI(null) to lookup the default namespace

 public String lookupPrefix(String namespaceURI) 
{
        
        // REVISIT: When Namespaces 1.1 comes out this may not be true
        // Prefix can't be bound to null namespace
        if (namespaceURI == null) {
            return null;
        }
        short type = this.getNodeType();
        switch (type) {
        case Node.ELEMENT_NODE: {
                this.getNamespaceURI(); // to flip out children 
                return lookupNamespacePrefix(namespaceURI, (ElementImpl)this);
            }
        case Node.DOCUMENT_NODE:{
                return((NodeImpl)((Document)this).getDocumentElement()).lookupPrefix(namespaceURI);
            }
        case Node.ENTITY_NODE :
        case Node.NOTATION_NODE:
        case Node.DOCUMENT_FRAGMENT_NODE:
        case Node.DOCUMENT_TYPE_NODE:
            // type is unknown
            return null;
        case Node.ATTRIBUTE_NODE:{
                if (this.ownerNode.getNodeType() == Node.ELEMENT_NODE) {
                    return ownerNode.lookupPrefix(namespaceURI);
                }
                return null;
            }
        default:{   
                NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
                if (ancestor != null) {
                    return ancestor.lookupPrefix(namespaceURI);
                }
                return null;
            }
        }
}

DOM Level 3 - Experimental: Look up the prefix associated to the given namespace URI, starting from this node.

 final boolean needsSyncChildren() 
{
        return (flags & SYNCCHILDREN) != 0;
}

 public final  void needsSyncChildren(boolean value) 
{
        flags = (short) (value ? flags | SYNCCHILDREN : flags & ~SYNCCHILDREN);
}

 final boolean needsSyncData() 
{
        return (flags & SYNCDATA) != 0;
}

 final  void needsSyncData(boolean value) 
{
        flags = (short) (value ? flags | SYNCDATA : flags & ~SYNCDATA);
}

 public  void normalize() 
{
	/* by default we do not have any children,
	   ParentNode overrides this behavior */
}

Puts all Text nodes in the full depth of the sub-tree underneath this Node, including attribute nodes, into a "normal" form where only markup (e.g., tags, comments, processing instructions, CDATA sections, and entity references) separates Text nodes, i.e., there are no adjacent Text nodes. This can be used to ensure that the DOM view of a document is the same as if it were saved and re-loaded, and is useful when operations (such as XPointer lookups) that depend on a particular document tree structure are to be used.In cases where the document contains CDATASections, the normalize operation alone may not be sufficient, since XPointers do not differentiate between Text nodes and CDATASection nodes.

Note that this implementation simply calls normalize() on this Node's children. It is up to implementors or Node to override normalize() to take action.

 CoreDocumentImpl ownerDocument() 
{
        // if we have an owner simply forward the request
        // otherwise ownerNode is our ownerDocument
        if (isOwned()) {
            return ownerNode.ownerDocument();
        } else {
            return (CoreDocumentImpl) ownerNode;
        }
}

same as above but returns internal type and this one is not overridden by CoreDocumentImpl to return null

 NodeImpl parentNode() 
{
        return null;
}

 ChildNode previousSibling() 
{
        return null;            // default behavior, overriden in ChildNode
}

 public Node removeChild(Node oldChild) throws DOMException 
{
	throw new DOMException(DOMException.NOT_FOUND_ERR, 
              DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN,
                 "NOT_FOUND_ERR", null));
}

Remove a child from this Node. The removed child's subtree remains intact so it may be re-inserted elsewhere.

By default we do not have any children, ParentNode overrides this.

 public  void removeEventListener(String type,
    EventListener listener,
    boolean useCapture) 
{
        // simply forward to Document
        ownerDocument().removeEventListener(this, type, listener, useCapture);
}

 public Node replaceChild(Node newChild,
    Node oldChild) throws DOMException 
{
	throw new DOMException(DOMException.HIERARCHY_REQUEST_ERR, 
              DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN,
                 "HIERARCHY_REQUEST_ERR", null));
}

Make newChild occupy the location that oldChild used to have. Note that newChild will first be removed from its previous parent, if any. Equivalent to inserting newChild before oldChild, then removing oldChild.

By default we do not have any children, ParentNode overrides this.

 public  void setNodeValue(String x) throws DOMException 
{
        // Default behavior is to do nothing, overridden in some subclasses
}

Sets the node value.

 protected  void setOwnerDocument(CoreDocumentImpl doc) 
{
        if (needsSyncData()) {
            synchronizeData();
        }
        // if we have an owner we rely on it to have it right
        // otherwise ownerNode is our ownerDocument
        if (!isOwned()) {
            ownerNode = doc;
        }
}

NON-DOM set the ownerDocument of this node

 public  void setPrefix(String prefix) throws DOMException 
{
	throw new DOMException(DOMException.NAMESPACE_ERR, 
              DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN,
                 "NAMESPACE_ERR", null));
}

Introduced in DOM Level 2.

The namespace prefix of this node, or null if it is unspecified. When this node is of any type other than ELEMENT_NODE and ATTRIBUTE_NODE this is always null and setting it has no effect.

For nodes created with a DOM Level 1 method, such as createElement from the Document interface, this is null.

Note that setting this attribute changes the nodeName attribute, which holds the qualified name, as well as the tagName and name attributes of the Element and Attr interfaces, when applicable.

 public  void setReadOnly(boolean readOnly,
    boolean deep) 
{
        if (needsSyncData()) {
            synchronizeData();
        }
    	isReadOnly(readOnly);
}

NON-DOM: PR-DOM-Level-1-19980818 mentions readonly nodes in conjunction with Entities, but provides no API to support this.

Most DOM users should not touch this method. Its anticpated use is during construction of EntityRefernces, where it will be used to lock the contents replicated from Entity so they can't be casually altered. It _could_ be published as a DOM extension, if desired.

Note: since we never have any children deep is meaningless here, ParentNode overrides this behavior.

 public  void setTextContent(String textContent) throws DOMException 
{
        setNodeValue(textContent);
}

This attribute returns the text content of this node and its descendants. When it is defined to be null, setting it has no effect. When set, any possible children this node may have are removed and replaced by a single Text node containing the string this attribute is set to. On getting, no serialization is performed, the returned string does not contain any markup. No whitespace normalization is performed, the returned string does not contain the element content whitespaces . Similarly, on setting, no parsing is performed either, the input string is taken as pure textual content.
The string returned is made of the text content of this node depending on its type, as defined below:

Node type	Content
ELEMENT_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE, DOCUMENT_FRAGMENT_NODE	concatenation of the textContent attribute value of every child node, excluding COMMENT_NODE and PROCESSING_INSTRUCTION_NODE nodes
ATTRIBUTE_NODE, TEXT_NODE, CDATA_SECTION_NODE, COMMENT_NODE, PROCESSING_INSTRUCTION_NODE	nodeValue
DOCUMENT_NODE, DOCUMENT_TYPE_NODE, NOTATION_NODE	null

 public  void setUserData(Object data) 
{
        ownerDocument().setUserData(this, data);
}

NON-DOM: As an alternative to subclassing the DOM, this implementation has been extended with the ability to attach an object to each node. (If you need multiple objects, you can attach a collection such as a vector or hashtable, then attach your application information to that.)

Important Note: You are responsible for removing references to your data on nodes that are no longer used. Failure to do so will prevent the nodes, your data is attached to, to be garbage collected until the whole document is.

 public Object setUserData(String key,
    Object data,
    UserDataHandler handler) 
{
        return ownerDocument().setUserData(this, key, data, handler);
}

Associate an object to a key on this node. The object can later be retrieved from this node by calling getUserData with the same key.

 protected  void synchronizeData() 
{
        // By default just change the flag to avoid calling this method again
        needsSyncData(false);
}

Override this method in subclass to hook in efficient internal data structure.

 public String toString() 
{
        return "["+getNodeName()+": "+getNodeValue()+"]";
}

NON-DOM method for debugging convenience.