1 /* 2 * Copyright (C) 2019 sw4j.org 3 * 4 * This program is free software: you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation, either version 3 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program. If not, see <http://www.gnu.org/licenses/>. 16 */ 17 package org.sw4j.tool.barcode.random.decoder; 18 19 import java.util.Iterator; 20 import java.util.ServiceLoader; 21 22 /** 23 * <p> 24 * This class is an interface for new Decoders (e.g. {@link org.sw4j.tool.barcode.random.encoder.impl.Base58Decoder}) 25 * and a factory for such decoders. 26 * </p> 27 * @author Uwe Plonus <u.plonus@gmail.com> 28 */ 29 public abstract class ByteArrayDecoder { 30 31 /** 32 * <p> 33 * For concrete decoders this method should return {@code true} if the given encoding is supported. 34 * </p> 35 * @param encoding the encoding to check for. 36 * @return {@code true} if the encoding is supported by the decoder. 37 */ 38 public abstract boolean supports(String encoding); 39 40 /** 41 * <p> 42 * Decode the given data into the encoding that is supported by the encoder. 43 * </p> 44 * @param data the data to decode. 45 * @return the decoded data. 46 */ 47 public abstract byte[] decode(String data); 48 49 /** 50 * <p> 51 * Return an decoder for the given encoding (e.g. {@code base58}). 52 * </p> 53 * @param encoding the encoding for which an decoder should be created. 54 * @return the decoder for the encoding or {@code null} if no decoder is available. 55 */ 56 public static ByteArrayDecoder forEncoding(final String encoding) { 57 ServiceLoader<ByteArrayDecoder> loader = ServiceLoader.load(ByteArrayDecoder.class); 58 Iterator<ByteArrayDecoder> iterator = loader.iterator(); 59 ByteArrayDecoder decoder = null; 60 while (iterator.hasNext() && decoder == null) { 61 ByteArrayDecoder dec = iterator.next(); 62 if (dec.supports(encoding)) { 63 decoder = dec; 64 } 65 } 66 return decoder; 67 } 68 69 }