/*

* Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  Entity Resolver for using external DTD files in XML parsing.

 *

*/

package com.nokia.tools.themeinstaller.xmlparser;

import java.io.IOException;

import org.xml.sax.EntityResolver;

import org.xml.sax.InputSource;

import org.xml.sax.SAXException;

/**

 * DTD Entity Resolver is for using external DTD files in XML parsing.

 * The resolveEntity method returns null if the provided system id does

 * not end with the ".dtd".

 */

public class DTDEntityResolver implements EntityResolver

    {

    // CONSTANTS

    // DTD file extension

    private static final String DTD_FILE_EXT = ".dtd";

    // File name of the external DTD

    private String iFileName;

    /**

     * Constructor.

     * @param aFileName file name of the DTD file

     */

    public DTDEntityResolver( String aFileName )

        {

        iFileName = aFileName;

        }

    /* (non-Javadoc)

     * @see org.xml.sax.EntityResolver#resolveEntity(java.lang.String, java.lang.String)

     */

    public InputSource resolveEntity( String aPublicId, String aSystemId )

            throws SAXException, IOException

        {

        DTDInputSource is = null;

        // For DTD files, provide input source containing the external DTD for

        // the XML parser

        if( aSystemId.endsWith( DTD_FILE_EXT ) )

            {

            is = new DTDInputSource( iFileName );

            }

        return is;

        }

    }