/* * jPOS Project [http://jpos.org] * Copyright (C) 2000-2017 jPOS Software SRL * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package org.jpos.iso; /** * This interface is used to encode and decode length prefixes. * * @author joconnor * @version $Revision$ $Date$ */ public interface Prefixer { /** * Fills a byte array with the field length data in raw form. * * @param length * The length to be encoded. * @param b * The byte array to fill with the encoded length. */ void encodeLength(int length, byte[] b) throws ISOException; /** * Decodes an encoded length. * * @param b * The byte array to scan for the length. * @param offset * The offset to start scanning from. * @return The length in chars of the field data to follow this * LengthPrefix. */ int decodeLength(byte[] b, int offset) throws ISOException; /** * Returns the number of bytes taken up by the length encoding. */ int getPackedLength(); }