ByteArrayDecoder.java

/*
 * Copyright (C) 2019 sw4j.org
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.sw4j.tool.barcode.random.decoder;

import java.util.Iterator;
import java.util.ServiceLoader;

/**
 * <p>
 * This class is an interface for new Decoders (e.g. {@link org.sw4j.tool.barcode.random.encoder.impl.Base58Decoder})
 * and a factory for such decoders.
 * </p>
 * @author Uwe Plonus &lt;u.plonus@gmail.com&gt;
 */
public abstract class ByteArrayDecoder {

    /**
     * <p>
     * For concrete decoders this method should return {@code true} if the given encoding is supported.
     * </p>
     * @param encoding the encoding to check for.
     * @return {@code true} if the encoding is supported by the decoder.
     */
    public abstract boolean supports(String encoding);

    /**
     * <p>
     * Decode the given data into the encoding that is supported by the encoder.
     * </p>
     * @param data the data to decode.
     * @return the decoded data.
     */
    public abstract byte[] decode(String data);

    /**
     * <p>
     * Return an decoder for the given encoding (e.g. {@code base58}).
     * </p>
     * @param encoding the encoding for which an decoder should be created.
     * @return the decoder for the encoding or {@code null} if no decoder is available.
     */
    public static ByteArrayDecoder forEncoding(final String encoding) {
        ServiceLoader<ByteArrayDecoder> loader = ServiceLoader.load(ByteArrayDecoder.class);
        Iterator<ByteArrayDecoder> iterator = loader.iterator();
        ByteArrayDecoder decoder = null;
        while (iterator.hasNext() && decoder == null) {
            ByteArrayDecoder dec = iterator.next();
            if (dec.supports(encoding)) {
                decoder = dec;
            }
        }
        return decoder;
    }

}