EncoderFactory.java

/**
 * Copyright (c) 2012, Ben Fortuna
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  o Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 *  o Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 *  o Neither the name of Ben Fortuna nor the names of any other contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package net.fortuna.ical4j.util;

import java.io.UnsupportedEncodingException;

import net.fortuna.ical4j.model.parameter.Encoding;

import org.apache.commons.codec.BinaryEncoder;
import org.apache.commons.codec.StringEncoder;

/**
 * Abstract base class for encoder factory implementations.
 * 
 * $Id$
 *
 * Created on 13/05/2006
 *
 * @author Ben Fortuna
 */
public abstract class EncoderFactory {
    
    /**
     * The system property used to specify an alternate
     * <code>EncoderFactory</code> implementation.
     */
    public static final String KEY_FACTORY_CLASS = "net.fortuna.ical4j.factory.encoder";

    private static EncoderFactory instance;
    static {
        try {
            final Class factoryClass = Class.forName(Configurator.getProperty(KEY_FACTORY_CLASS));
            instance = (EncoderFactory) factoryClass.newInstance();
        }
        catch (Exception e) {
            instance = new DefaultEncoderFactory();
        }
    }
    
    /**
     * @return Returns the instance.
     */
    public static final EncoderFactory getInstance() {
        return instance;
    }

    /**
     * Returns a new {@link BinaryEncoder} for the specified encoding.
     * @param encoding an encoding type
     * @return a {@link BinaryEncoder} instance
     * @throws UnsupportedEncodingException where an encoder supporting the
     * specified encoding is not available.
     */
    public abstract BinaryEncoder createBinaryEncoder(Encoding encoding)
        throws UnsupportedEncodingException;
    
    /**
     * Returns a new {@link StringEncoder} for the specified encoding.
     * @param encoding an encoding type
     * @return a {@link StringEncoder} instance
     * @throws UnsupportedEncodingException where an encoder supporting the
     * specified encoding is not available.
     */
    public abstract StringEncoder createStringEncoder(Encoding encoding)
        throws UnsupportedEncodingException;
}