entityreferenceimpl.java

用Java写的面相对象的数据库管理系统

/**
 * org/ozone-db/xml/dom/EntityReferenceImpl.java
 *
 * The contents of this file are subject to the OpenXML Public
 * License Version 1.0; you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 * http://www.openxml.org/license.html
 *
 * THIS SOFTWARE IS DISTRIBUTED ON AN "AS IS" BASIS WITHOUT WARRANTY
 * OF ANY KIND, EITHER EXPRESSED OR IMPLIED. THE INITIAL DEVELOPER
 * AND ALL CONTRIBUTORS SHALL NOT BE LIABLE FOR ANY DAMAGES AS A
 * RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. SEE THE LICENSE FOR THE SPECIFIC LANGUAGE GOVERNING
 * RIGHTS AND LIMITATIONS UNDER THE LICENSE.
 *
 * The Initial Developer of this code under the License is Assaf Arkin.
 * Portions created by Assaf Arkin are Copyright (C) 1998, 1999.
 * All Rights Reserved.
 */

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

package org.ozoneDB.xml.dom;

import org.w3c.dom.*;


/**
 * Implements an entity reference. Entity references are read-only when an XML
 * document is parsed, but are modifiable when an XML document is created in
 * memory.
 * <P>
 * Notes:
 * <OL>
 * <LI>Node type is {@link org.w3c.dom.Node#ENTITY_REFERENCE_NODE}
 * <LI>Node supports childern
 * <LI>Node does not have a value
 * <LI>One of two nodes that may be added to an attribute or an element
 * </OL>
 *
 *
 * @version $Revision: 1.12 $ $Date: 2000/10/28 16:55:23 $
 * @author <a href="mailto:[e-mail]">Assaf Arkin</a>
 * @see org.w3c.dom.EntityReference
 * @see NodeImpl
 */
public final class EntityReferenceImpl extends NodeImpl implements EntityReferenceProxy {
    
    final static long serialVersionUID = 1;
    
    
    public short getNodeType() {
        return this.ENTITY_REFERENCE_NODE;
    } 
    
    
    public final void setNodeValue( String value ) {
        throw new DOMExceptionImpl( DOMException.NO_DATA_ALLOWED_ERR, "This node type does not support values." );
    } 
    
    
    public final Object clone() {
        EntityReferenceProxy clone = null;
        try {
            clone = (EntityReferenceProxy)database().createObject( EntityReferenceImpl.class.getName() );
            clone.init( _ownerDocument, getNodeName() );
            cloneInto( (NodeProxy)clone, true );
        } catch (Exception except) {
            throw new DOMExceptionImpl( DOMExceptionImpl.PDOM_ERR, except.getMessage() );
        } 
        return clone;
    } 
    
    
    public final Node cloneNode( boolean deep ) {
        EntityReferenceProxy clone = null;
        try {
            clone = (EntityReferenceProxy)database().createObject( EntityReferenceImpl.class.getName() );
            clone.init( _ownerDocument, getNodeName() );
            cloneInto( (NodeProxy)clone, deep );
        } catch (Exception except) {
            throw new DOMExceptionImpl( DOMExceptionImpl.PDOM_ERR, except.getMessage() );
        } 
        return clone;
    } 
    
    
    public String toString() {
        String name;
        
        name = getNodeName();
        if (name.length() > 32) {
            name = name.substring( 0, 32 ) + "..";
        } 
        return "Entity ref: [" + name + "]";
    } 
    
    
    protected final boolean supportsChildern() {
        return true;
    } 
    
    /**
     * Parses an entity reference based on the entities contained in the document.
     * If an entity with a matching name is found, it is parsed and the textual
     * value is returned. Otherwise, an empty string is returned.
     *
     * @return Parsed entity reference or empty string
     */
    /*
    synchronized String parseEntity() {
        NamedNodeMap    entities;
        Node            node;
        StringBuffer    parsed;
        DocumentType    docType;

        parsed = new StringBuffer();
        // This document supports attribute children as per the XML spec
        docType = getDocument().getDoctype();
        if ( docType != null ) {
            entities = docType.getEntities();
            node = entities.getNamedItem( getNodeName() );
            if ( node != null )
                synchronized ( node ) {
                    node = node.getFirstChild();
                    while ( node != null ) {
                        if ( node instanceof Text )
                            parsed.append( ( (Text) node ).getData() );
                        else
                        if ( node instanceof EntityReference )
                            parsed.append( ( (EntityReferenceImpl) node ).parseEntity() );
                        node = node.getNextSibling();
                        }
                    }
            }
        return parsed.toString();
        }
     */
    
    
    /**
     * Constructor requires only owner document and entity name.
     *
     * @param owner The owner of this document
     * @param name The entity name
     */
    EntityReferenceImpl( DocumentImpl owner, String name ) {
        super( owner, name, null, true );
    }
    
    
    public EntityReferenceImpl() {
        super();
    }
    
    
    public void init( DocumentProxy owner, String name ) {
        super.init( owner, name, null, true );
    } 
}