nodeimpl.java

Java的面向对象数据库系统的源代码

/**
 * Changes for Persistent DOM running with ozone are
 * Copyright 1999 by SMB GmbH. All rights reserved.
 */

package org.ozoneDB.xml.dom;

import java.io.*;
import org.ozoneDB.*;
import org.ozoneDB.xml.dom.iterator.*;
import org.w3c.dom.*;


public abstract class NodeImpl extends OzoneObject implements NodeProxy, Externalizable {

    final static long serialVersionUID = 1;

    //    public Object invoke (String methodName, String sig, Object[] args)
    //            throws Exception {
    //        if (methodName.equals ("getNodeName")
    //            return
    //        }


    public boolean supports( java.lang.String feature, java.lang.String version ) {
        throw new DOMExceptionImpl( DOMException.NOT_SUPPORTED_ERR,
                "Node.supports(): ozone's persistent DOM doesn't support DOM level 2 yet." );
    }


    public void normalize() {
        throw new DOMExceptionImpl( DOMException.NOT_SUPPORTED_ERR,
                "Node.normalize(): ozone's persistent DOM doesn't support DOM level 2 yet." );
    }


    public java.lang.String getNamespaceURI() {
        // FIXME:
        //  throw new DOMExceptionImpl( DOMException.NOT_SUPPORTED_ERR,
        //          "Node.getNamespaceURI(): ozone's persistent DOM doesn't support DOM level 2 yet." );
        return null;
    }


    public java.lang.String getPrefix() {
        throw new DOMExceptionImpl( DOMException.NOT_SUPPORTED_ERR,
                "Node.getPrefix(): ozone's persistent DOM doesn't support DOM level 2 yet." );
    }


    public void setPrefix( java.lang.String prefix ) throws DOMException {
        throw new DOMExceptionImpl( DOMException.NOT_SUPPORTED_ERR,
                "Node.setPrefix(): ozone's persistent DOM doesn't support DOM level 2 yet." );
    }


    public java.lang.String getLocalName() {
        throw new DOMExceptionImpl( DOMException.NOT_SUPPORTED_ERR,
                "Node.getLocalName(): ozone's persistent DOM doesn't support DOM level 2 yet." );
    }


    /**
     * Abstract method must be implemented by each node class.
     *
     * @see org.w3c.dom.Node#getNodeType
     */
    public abstract short getNodeType();


    /**
     * Returns the name of the node, set from the constructor. Some derived classes
     * do not have the notion of a name, and will return the same name each time.
     * They should do so by setting the default name (e.g. <TT>"#comment"</TT>)
     * in the constructor. This value is never null.
     *
     * @see org.w3c.dom.Node#getNodeName
     */
    public final String getNodeName() {
        return _nodeName;
    }


    /**
     */
    public final void setNodeName( String nodeName ) {
        _nodeName = nodeName;
    }


    /**
     * Returns the value of the node. Depending on the node type, this value
     * is either the node value (e.g. the text in {@link org.w3c.dom.Text}),
     * or always null is node has no notion of a value (e.g. {@link
     * org.w3c.dom.Element}). For complete list of which node types will return
     * what, see {@link #setNodeValue}.
     *
     * @return Value of node, null if node has no value
     */
    public final String getNodeValue() {
        return _nodeValue;
    }


    /**
     * Changes the value of the node. Not all node types support the notion of
     * a value. If the value is not supported by a particular node type, it will
     * throw an exception when calling this method. The following table specifies
     * which node types support values:
     * <PRE>
     * Element                  Not supported
     * Attr                     Value supported
     * Text                     Value supported
     * CDATASection             Value supported
     * EntityReference          Not supported
     * Entity                   Not supported
     * ProcessingInstruction    Value supported
     * Comment                  Value supported
     * Document                 Not supported
     * DocumentType             Not supported
     * DocumentFragment         Not supported
     * Notation                 Not supported
     * </PRE>
     * For most node types, if the value is set to null, {@link #getNodeValue}
     * will return an empty string instead.
     *
     * @param value New value of node
     * @throws org.w3c.dom.DOMException <TT>NO_MODIFICATION_ALLOWED_ERR</TT>
     *  Node is read-only and cannot be modified
     * @throws org.w3c.dom.DOMException <TT>NO_DATA_ALLOWED_ERR</TT>
     *  This node does not support a value
     */
    public void setNodeValue( String value ) {
        if (isReadOnly()) {
            throw new DOMExceptionImpl( DOMException.NO_MODIFICATION_ALLOWED_ERR );
        }
        _nodeValue = value == null ? "" : value;
    }


    /**
     * Returns the parent node of this node. Node may not necessarily have a
     * parent node. If node has been created but not added to any other node,
     * it will be parentless. The {@link org.w3c.dom.Document} node is always
     * parentless.
     *
     * @return Parent node of this node
     */
    public Node getParentNode() {
        return _parent;
    }


    /**
     */
    public void setParentNode( Node newParent ) {
        _parent = (NodeProxy)newParent;
    }


    /**
     * Called to notify all the iterators created from this node that a
     * child of this node has been removed. Iterators that point at this
     * child might choose to select another child to point to. This method
     * is called before the child is removed.
     * <P>
     * The removed node is a direct child of this node. Affected iterators
     * are those that point at the document tree directly below this node,
     * or the tree below one of its parents. Other iterators are not affected
     * by the change. This method also performs a notification on all the
     * parents of this node.
     *
     * @param removedChild The child node being removed
     */
    protected void notifyIterators( Node removedChild ) {
    /*
FIXME
        NodeProxy   node;
        int         i;

        node = this;
        while ( node != null ) {
            if ( node._iterators != null )
                for ( i = node._iterators.length ; i -- > 0 ; )
                    ( (NodeIteratorListener) node._iterators[ i ] ).removeNode( removedChild );
            node = (NodeProxy) node.getParentNode();
            }
     */
    }


    /**
     * Returns a {@link org.w3c.dom.NodeList} object that can be used to traverse
     * this node's children. The node list is live, so every change to this node
     * is reflected in it.
     * <P>
     * If children are not supported by the derived class, an exception is thrown.
     *
     * @return {@link org.w3c.dom.NodeList} on this node
     * @throws org.w3c.dom.DOMException HIERARCHY_REQUEST_ERR Childern not supported
     *  by this node type
     * @see org.w3c.dom.NodeList
     * @see NodeListImpl
     */
    public NodeList getChildNodes() {
        // Throw exception if children not supported by derived class.
        if (!supportsChildern()) {
            throw new DOMExceptionImpl( DOMException.HIERARCHY_REQUEST_ERR,
                    "No childern supported by this node type." );
        }
        return new org.ozoneDB.xml.dom.NodeListImpl( this );
    }


    /**
     * Returns the first child of the node. If node has no children, returns null.
     *
     * @return First child or null
     */
    public final Node getFirstChild() {
        return _firstChild;
    }


    /**
     * Returns the last child of the node. If node has no children, returns null.
     *
     * @return Last child or null
     */
    public final Node getLastChild() {
        return _lastChild;
    }


    /**
     * Returns the previous sibling of this node. If node has no previous siblings,
     * returns null.
     *
     * @return Previous sibling or null
     */
    public Node getPreviousSibling() {
        return _prevNode;
    }


    /**
     */
    public void setPreviousSibling( Node prevNode ) {
        _prevNode = (NodeProxy)prevNode;
    }


    /**
     * Returns the next sibling of this node. If node has no next siblings,
     * returns null.
     *
     * @return Next sibling or null
     */
    public Node getNextSibling() {
        return _nextNode;
    }


    /**
     */
    public void setNextSibling( Node nextNode ) {
        _nextNode = (NodeProxy)nextNode;
    }


    /**
     * Return attributes of node. Returns null unless node is of type {@link
     * org.w3c.dom.Element}, in which case the returned {@link
     * org.w3c.dom.NamedNodeMap} will provide access to all the element's
     * attributes.
     *
     * @return Attributes of node or null
     */
    public NamedNodeMap getAttributes() {
        return null;
    }


    public boolean hasAttributes() {
        throw new DOMExceptionImpl( DOMException.NOT_SUPPORTED_ERR,
                "ozone's persistent DOM doesn't support DOM level 2 yet." );
    }




    public final Document getOwnerDocument() {
        if (_ownerDocument != this) {
            return _ownerDocument;
        } else {
            return null;
        }
    }


    /**
     * Return true if there are any childern to this node. Less intensive than
     * calling {#link getChildNodes}.
     *
     * @return True if node has any children
     */
    public final boolean hasChildNodes() {
        return _firstChild != null;
    }


    /**
     * Insert <TT>newChild</TT> as the last child of this parent.
     * <P>
     * If <TT>newChild</TT> is null, <TT>newChild</TT> does not belong to this DOM,
     * or childern are not supported by this node type, an exception is thrown.
     * <P>
     * <TT>newChild</TT> is removed from its original parent before adding to this
     * parent. If <TT>newChild</TT> is a {@link org.w3c.dom.DocumentFragment}, all
     * its children are inserted one by one into this parent.
     *
     * @param newChild The new child to add
     * @return The newly inserted child
     * @throws org.w3c.dom.DOMException <TT>NO_MODIFICATION_ALLOWED_ERR</TT>
     *  Node is read-only and cannot be modified
     * @throws org.w3c.dom.DOMException <TT>HIERARCHY_REQUEST_ERR</TT>
     *  Children are not supported by this node type, or <TT>newChild</TT> is not
     *  a compatible type for this node
     * @see #castNewChild
     * @see #castOldChild
     */
    public synchronized final Node appendChild( Node newChild ) {
        // Node arguments must be casted to NodeEx in order to operate on them.
        NodeProxy newChildX;

        // Make sure the node is not read-only.
        // Throw exception if children not supported by derived class.
        if (isReadOnly()) {
            throw new DOMExceptionImpl( DOMException.NO_MODIFICATION_ALLOWED_ERR );
        }
        if (!supportsChildern()) {
            throw new DOMExceptionImpl( DOMException.HIERARCHY_REQUEST_ERR,
                    "No childern supported by this node type." );
        }

        // Cast newChild to NodeImpl and make sure it can be inserted to this node.
        newChildX = (NodeProxy)castNewChild( newChild );

        // We're going to mess with this child node, so make sure no other thread
        // is touching it
        synchronized (newChild) {
            // If the newChild is already a child or some node, remove it first
            // before becoming child of this node. Make sure that parent is not
            // read-only.
            if (newChildX.getParentNode() != null) {
                if (((NodeProxy)newChildX.getParentNode()).isReadOnly()) {
                    throw new DOMExceptionImpl( DOMException.NO_MODIFICATION_ALLOWED_ERR );
                }
                newChildX.getParentNode().removeChild( newChildX );
            }

            // Special case: newChild is a DocumentFragment and instead of adding
            // itself, all of its childs are added one by one.
            if (newChildX instanceof DocumentFragment) {
                NodeProxy nextChild;

                newChildX = (NodeProxy)newChildX.getFirstChild();
                while (newChildX != null) {
                    nextChild = (NodeProxy)newChildX.getNextSibling();