/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * Copyright 1999-2002,2004 The Apache Software Foundation.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.sun.org.apache.xml.internal.serialize;

import java.io.OutputStream;

import java.io.Writer;

import java.io.UnsupportedEncodingException;

import java.util.Hashtable;

import java.util.StringTokenizer;

/**

 *

 *

 * @author <a href="mailto:Scott_Boag/CAM/Lotus@lotus.com">Scott Boag</a>

 * @author <a href="mailto:arkin@intalio.com">Assaf Arkin</a>

 */

public abstract class SerializerFactory

{

    public static final String FactoriesProperty = "com.sun.org.apache.xml.internal.serialize.factories";

    private static Hashtable  _factories = new Hashtable();

    static

    {

        SerializerFactory factory;

        String            list;

        StringTokenizer   token;

        String            className;

        // The default factories are always registered first,

        // any factory specified in the properties file and supporting

        // the same method will override the default factory.

        factory =  new SerializerFactoryImpl( Method.XML );

        registerSerializerFactory( factory );

        factory =  new SerializerFactoryImpl( Method.HTML );

        registerSerializerFactory( factory );

        factory =  new SerializerFactoryImpl( Method.XHTML );

        registerSerializerFactory( factory );

        factory =  new SerializerFactoryImpl( Method.TEXT );

        registerSerializerFactory( factory );

        list = System.getProperty( FactoriesProperty );

        if ( list != null ) {

            token = new StringTokenizer( list, " ;,:" );

            while ( token.hasMoreTokens() ) {

                className = token.nextToken();

                try {

                    factory = (SerializerFactory) ObjectFactory.newInstance( className,

                        SerializerFactory.class.getClassLoader(), true);

                    if ( _factories.containsKey( factory.getSupportedMethod() ) )

                        _factories.put( factory.getSupportedMethod(), factory );

                } catch ( Exception except ) { }

            }

        }

    }

    /**

     * Register a serializer factory, keyed by the given

     * method string.

     */

    public static void registerSerializerFactory( SerializerFactory factory )

    {

        String method;

        synchronized ( _factories ) {

            method = factory.getSupportedMethod();

            _factories.put( method, factory );

        }

    }

    /**

     * Register a serializer factory, keyed by the given

     * method string.

     */

    public static SerializerFactory getSerializerFactory( String method )

    {

        return (SerializerFactory) _factories.get( method );

    }

    /**

     * Returns the method supported by this factory and used to register

     * the factory. This call is required so factories can be added from

     * a properties file by knowing only the class name. This method is

     * protected, it is only required by this class but must be implemented

     * in derived classes.

     */

    protected abstract String getSupportedMethod();

    /**

     * Create a new serializer based on the {@link OutputFormat}.

     * If this method is used to create the serializer, the {@link

     * Serializer#setOutputByteStream} or {@link Serializer#setOutputCharStream}

     * methods must be called before serializing a document.

     */

    public abstract Serializer makeSerializer(OutputFormat format);

    /**

     * Create a new serializer, based on the {@link OutputFormat} and

     * using the writer as the output character stream.  If this

     * method is used, the encoding property will be ignored.

     */

    public abstract Serializer makeSerializer( Writer writer,

                                               OutputFormat format );

    /**

     * Create a new serializer, based on the {@link OutputFormat} and

     * using the output byte stream and the encoding specified in the

     * output format.

     *

     * @throws UnsupportedEncodingException The specified encoding is

     *   not supported

     */

    public abstract Serializer makeSerializer( OutputStream output,

                                               OutputFormat format )

        throws UnsupportedEncodingException;

}