entityimpl.java

用Java写的面相对象的数据库管理系统

/**
 * org/ozone-db/xml/dom/EntityImpl.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 java.io.*;
import org.w3c.dom.*;


/**
 * Implements an entity.
 * <P>
 * Notes:
 * <OL>
 * <LI>Node type is {@link org.w3c.dom.Node#ENTITY_NODE}
 * <LI>Node supports childern
 * <LI>Node does not have a value
 * <LI>Node only accessible from {@link org.w3c.dom.DocumentType}
 * </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.Entity
 * @see NodeImpl
 */
public class EntityImpl extends NodeImpl implements EntityProxy, Externalizable {
    
    final static long serialVersionUID = 1;
    
    
    public short getNodeType() {
        return ENTITY_NODE;
    } 
    
    
    public final void setNodeValue( String value ) {
        throw new DOMExceptionImpl( DOMException.NO_DATA_ALLOWED_ERR, "This node type does not support values." );
    } 
    
    
    public String getPublicId() {
        return _publicId;
    } 
    
    
    public void setPublicId( String publicId ) {
        _publicId = publicId;
    } 
    
    
    public String getSystemId() {
        return _systemId;
    } 
    
    
    public void setSystemId( String systemId ) {
        _systemId = systemId;
    } 
    
    
    public String getNotationName() {
        return _notation;
    } 
    
    
    public void setNotationName( String notation ) {
        _notation = notation;
    } 
    
    
    public final String getInternal() {
        return _internalValue;
    } 
    
    
    /**
     * Returns true if entity is an unparsed general entity. An unparsed entity
     * is one for which a notation has been specified.
     *
     * @return True if unparsed general entity
     */
    public boolean isUnparsed() {
        return _notation != null;
    } 
    
    
    /**
     * Returns true if entity is an internal general entity. An internal entity
     * is one for which a value has been defined. An external entity is one for
     * which an external entity has been assigned through either system or
     * public identifiers.
     * <P>
     * If true is returned, then {@link #getInternal} will return a string
     * (might be empty).
     *
     * @return True if internal general entity
     */
    public boolean isInternal() {
        return _internalValue != null;
    } 
    
    
    public void setInternal( String internalValue ) {
        _internalValue = internalValue;
    } 
    
    
    /**
     * Returns the parsing state of this entity.
     *
     * @return State of entity
     */
    public short getState() {
        return _state;
    } 
    
    
    /**
     * Changes the parsing state of this entity. Note that only some changes
     * are allowed: from declared to parsing, parsed or not found; from parsing
     * to parsed or not found; from not found to declared.
     *
     * @param newState New state of entity
     */
    public void setState( short newState ) {
        if (_state == STATE_DECLARED && newState == STATE_PARSING || _state == STATE_NOT_FOUND && newState 
                == STATE_DECLARED) {
            _state = newState;
        } else if ((_state == STATE_DECLARED || _state == STATE_PARSING) && (newState == STATE_PARSED || newState 
                == STATE_NOT_FOUND)) {
            _state = newState;
        } else {
            throw new IllegalStateException( "Cannot switch from state " + _state + " to state " + newState + "." );
        } 
    } 
    
    
    public synchronized boolean equals( Object other ) {
        EntityProxy otherX;
        
        // Test for node equality (this covers entity name and all its children)
        // and then test for specific entity qualities.
        if (super.equals( other )) {
            otherX = (EntityProxy)other;
            // If this entity is internal, both entities must be internal and have
            // equal internal value.
            if (this.isInternal()) {
                return otherX.isInternal() && this.getInternal().equals( otherX.getInternal() );
            } 
            // External or unparsed: either public id are both null, or public id
            // equals in both (and same for system id and notation).
            return 
                    (this.getPublicId() == null && otherX.getPublicId() == null || this.getPublicId() != null 
                    && this.getPublicId().equals( otherX.getPublicId() )) && (this.getSystemId() == null 
                    && otherX.getSystemId() == null || this.getSystemId() != null && this.getSystemId().equals(
                    otherX.getSystemId() )) && (this.getNotationName() == null && otherX.getNotationName() == null 
                    || this.getNotationName() != null && this.getNotationName().equals( otherX.getNotationName() ));
        } 
        return false;
    } 
    
    
    public final Object clone() {
        EntityProxy clone = null;
        try {
            clone = (EntityProxy)database().createObject( EntityImpl.class.getName() );
            clone.init( _ownerDocument, getNodeName() );
            cloneInto( clone, true );
        } catch (Exception except) {
            throw new DOMExceptionImpl( DOMExceptionImpl.PDOM_ERR, except.getMessage() );
        } 
        return clone;
    } 
    
    
    public final Node cloneNode( boolean deep ) {
        EntityProxy clone = null;
        try {
            clone = (EntityProxy)database().createObject( EntityImpl.class.getName() );
            clone.init( _ownerDocument, getNodeName() );
            cloneInto( clone, deep );
        } catch (Exception except) {
            throw new DOMExceptionImpl( DOMExceptionImpl.PDOM_ERR, except.getMessage() );
        } 
        return clone;
    } 
    
    
    public String toString() {
        String name;
        String value;
        
        name = getNodeName();
        if (name.length() > 32) {
            name = name.substring( 0, 32 ) + "..";
        } 
        if (isInternal()) {
            value = getInternal();
            if (value.length() > 64) {
                value = value.substring( 0, 64 ) + "..";
            } 
            name = name + "] [" + value;
        } else {
            if (getSystemId() != null) {
                name = name + "] SYSTEM [" + getSystemId();
            } 
            if (getPublicId() != null) {
                name = name + "] PUBLIC [" + getPublicId();
            } 
            if (getNotationName() != null) {
                name = name + "] NDECL [" + getNotationName();
            } 
        } 
        return "Entity decl: [" + name + "]";
    } 
    
    
    protected final boolean supportsChildern() {
        return true;
    } 
    
    
    public synchronized void cloneInto( NodeProxy into, boolean deep ) {
        super.cloneInto( into, deep );
        ((EntityProxy)into).setSystemId( this._systemId );
        ((EntityProxy)into).setPublicId( this._publicId );
        ((EntityProxy)into).setNotationName( this._notation );
        ((EntityProxy)into).setInternal( this._internalValue );
        ((EntityProxy)into).setState( this._state );
    } 
    
    
    /**
     * Constructs an unparsed general entity. Entity system identifier and notation
     * name must be provided, public identifier is optional.
     *
     * @param owner The owner document
     * @param name The entity name
     * @param systemId The system identifier
     * @param publicId The public identifier, if specified
     * @param notation The notation, if specified
     */
    public EntityImpl( DocumentImpl owner, String name, String systemId, String publicId, String notation ) {
        super( owner, name, null, true );
        if (notation == null) {
            throw new NullPointerException( "Argument 'notation' cannot be null." );
        } else {
            init( owner, name, systemId, publicId, notation );
        } 
    }
    
    
    /**
     * Constructs an external general entity. Entity system identifier must be
     * provided, public identifier is optional.
     *
     * @param owner The owner document
     * @param name The entity name
     * @param systemId The system identifier
     * @param publicId The public identifier, if specified
     */
    public EntityImpl( DocumentImpl owner, String name, String systemId, String publicId ) {
        super( owner, name, null, true );
        if (systemId == null) {
            throw new NullPointerException( "Argument 'systemId' cannot be null." );
        } else {
            init( owner, name, systemId, publicId );
        } 
    }
    
    
    /**
     * Constructs an internal general entity. Entity value must be provided.
     *
     * @param owner The owner document
     * @param name The entity name
     * @param internalValue The unparsed entity value
     */
    public EntityImpl( DocumentImpl owner, String name, String internalValue ) {
        super( owner, name, null, true );
        if (internalValue == null) {
            throw new NullPointerException( "Argument 'internalValue' cannot be null." );
        } else {
            init( owner, name, internalValue );
        } 
    }
    
    
    private EntityImpl( DocumentImpl owner, String name ) {
        super( owner, name, null, true );
    }
    
    
    public EntityImpl() {
        super();
    }
    
    
    public void init( DocumentProxy owner, String name ) {
        super.init( owner, name, null, true );
    } 
    
    
    public void init( DocumentProxy owner, String name, String value ) {
        _systemId = null;
        _publicId = null;
        _notation = null;
        _state = STATE_DECLARED;
        _internalValue = value;
    } 
    
    
    public void init( DocumentProxy owner, String name, String systemId, String publicId ) {
        _systemId = systemId;
        _publicId = publicId;
        _notation = null;
        _state = STATE_DECLARED;
    } 
    
    
    public void init( DocumentProxy owner, String name, String systemId, String publicId, String notation ) {
        _systemId = systemId;
        _publicId = publicId;
    } 
    
    
    /** */
    public void writeExternal( ObjectOutput out ) throws IOException {
        super.writeExternal( out );
        out.writeObject( _notation );
        out.writeObject( _systemId );
        out.writeObject( _publicId );
        out.writeShort( _state );
        out.writeObject( _internalValue );
    } 
    
    
    /** */
    public void readExternal( ObjectInput in ) throws IOException, ClassNotFoundException {
        super.readExternal( in );
        _notation = (String)in.readObject();
        _systemId = (String)in.readObject();
        _publicId = (String)in.readObject();
        _state = in.readShort();
        _internalValue = (String)in.readObject();
    } 
    
    
    /**
     * The notation of this entity, if specified.
     */
    protected String _notation;
    
    /**
     * The system identifier of this entity, if specified.
     */
    protected String _systemId;
    
    /**
     * The public identifier of this entity, if specified.
     */
    protected String _publicId;
    
    /**
     * Identifies the state of this entity as yet to be parsed, being parsed,
     * has been parsed, or cannot be found.
     */
    private short _state;
    
    /**
     * Holds the internal value of the entity.
     */
    private String _internalValue;
    
    /**
     * Entity has been declared but not parsed. This is the initial state for
     * an entity after it has been declared in the DTD but before it is used
     * in the document contents.
     */
    public final static short STATE_DECLARED = 0;
    
    /**
     * Entity is being parsed. This state designates that the entity is being
     * parsed right now. State is used to identify circular references.
     */
    public final static short STATE_PARSING = 1;
    
    /**
     * Entity has been parsed. This state indicates that entity has been parsed
     * and it's parsed contents is contained in its child nodes.
     */
    public final static short STATE_PARSED = 2;
    
    /**
     * Entity not found. The entity could not be parsed before.
     */
    public final static short STATE_NOT_FOUND = 3;
    
}