/*

* 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:  String pool for DOM Externalizer.

 *

*/

package com.nokia.tools.themeinstaller.odtconverter;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.util.Vector;

/**

 * String pool is a set of strings where a string is only listed once.

 */

public class StringPool

    {

    // The pool for storing the strings

    private Vector iStringPool;

    /**

     * Constructor.

     */

    public StringPool()

        {

        iStringPool = new Vector();

        }

    /**

     * Add a string to the pool. Each string is added only once.

     * @param aString String to add

     * @return Index in the pool

     */

    public int addString( String aString )

        {

        if( aString == null )

            {

            aString = "";

            }

        if( !iStringPool.contains( aString ) )

            {

            iStringPool.addElement( aString );

            }

        return iStringPool.lastIndexOf( aString );

        }

    /**

     * Get a string from the pool.

     * @param aIndex Index number of the string

     * @return The requested string

     */

    public String getString( int aIndex )

        {

        return ( String ) iStringPool.elementAt( aIndex );

        }

    /**

     * Get string pool contents in a byte array.

     * @return String pool contents in a byte array

     * @throws IOException if writing to a stream fails

     * @throws ODTException if writing to a stream fails

     */

    public byte[] toByteArray() throws IOException, ODTException

        {

        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        ODTDataOutputStream dos = new ODTDataOutputStream( baos );

        int count = iStringPool.size();

        byte[] result = null;

        try

            {

            // Write string count and each string to the stream

            dos.writeInt16( count );

            for( int i = 0; i < count; i++ )

                {

                String string = ( String ) iStringPool.elementAt( i );

                dos.writeInt16( string.length() );

                dos.writeString8( string );

                }

            result = baos.toByteArray();

            }

        finally

            {

            if( dos != null )

                {

                dos.close();

                }

            if( baos != null )

                {

                baos.close();

                }

            }

        return result;

        }

    }