001/*
002 * jPOS Project [http://jpos.org]
003 * Copyright (C) 2000-2026 jPOS Software SRL
004 *
005 * This program is free software: you can redistribute it and/or modify
006 * it under the terms of the GNU Affero General Public License as
007 * published by the Free Software Foundation, either version 3 of the
008 * License, or (at your option) any later version.
009 *
010 * This program is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
013 * GNU Affero General Public License for more details.
014 *
015 * You should have received a copy of the GNU Affero General Public License
016 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
017 */
018
019package org.jpos.iso;
020
021
022/**
023 * Implements the Padder interface for padding strings and byte arrays on the
024 * Right.
025 * 
026 * @author joconnor
027 * @version $Revision$ $Date$
028 */
029public class RightPadder implements Padder
030{
031    /**
032         * A padder for padding spaces on the right. This is very common in
033         * alphabetic fields.
034         */
035    public static final RightPadder SPACE_PADDER = new RightPadder(' ');
036
037    private char pad;
038
039    /**
040         * Creates a Right Padder with a specific pad character.
041         * 
042         * @param pad
043         *            The padding character. For binary padders, the pad character
044         *            is truncated to lower order byte.
045         */
046    public RightPadder(char pad)
047    {
048        this.pad = pad;
049    }
050
051    public String pad(String data, int maxLength) throws ISOException {
052        if (maxLength < 0)
053            throw new ISOException ("invalid maxLength " + maxLength);
054        int len = data.length();
055
056        if (len < maxLength) {
057            StringBuilder padded = new StringBuilder(maxLength);
058            padded.append(data);
059            for (; len < maxLength; len++) {
060                padded.append(pad);
061            }
062            data = padded.toString();
063        }
064        else if (len > maxLength) {
065            throw new ISOException("Data is too long. Max = " + maxLength);
066        }
067        return data;
068    }
069
070    public String unpad(String paddedData)
071    {
072        int len = paddedData.length();
073        for (int i = len; i > 0; i--)
074        {
075            if (paddedData.charAt(i - 1) != pad)
076            {
077                return paddedData.substring(0, i);
078            }
079        }
080        return "";
081    }
082}