Java tutorial
/* * $Id: RomanNumberFactory.java 3373 2008-05-12 16:21:24Z xlv $ * * Copyright 2007 by Bruno Lowagie. * * The contents of this file are subject to the Mozilla Public License Version 1.1 * (the "License"); you may not use this file except in compliance with the License. * You may obtain a copy of the License at http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the License. * * The Original Code is 'iText, a free JAVA-PDF library'. * * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie. * All Rights Reserved. * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved. * * Contributor(s): all the names of the contributors are added in the source code * where applicable. * * Alternatively, the contents of this file may be used under the terms of the * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the * provisions of LGPL are applicable instead of those above. If you wish to * allow use of your version of this file only under the terms of the LGPL * License and not to allow others to use your version of this file under * the MPL, indicate your decision by deleting the provisions above and * replace them with the notice and other provisions required by the LGPL. * If you do not delete the provisions above, a recipient may use your version * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE. * * This library is free software; you can redistribute it and/or modify it * under the terms of the MPL as stated above or under the terms of the GNU * Library General Public License as published by the Free Software Foundation; * either version 2 of the License, or any later version. * * This library 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 Library general Public License for more * details. * * If you didn't download this code from the following link, you should check if * you aren't using an obsolete version: * http://www.lowagie.com/iText/ */ package com.lowagie.text.factories; /** * This class can produce String combinations representing a roman number. */ public class RomanNumberFactory { /** * Helper class for Roman Digits */ private static class RomanDigit { /** part of a roman number */ public char digit; /** value of the roman digit */ public int value; /** can the digit be used as a prefix */ public boolean pre; /** * Constructs a roman digit * @param digit the roman digit * @param value the value * @param pre can it be used as a prefix */ RomanDigit(char digit, int value, boolean pre) { this.digit = digit; this.value = value; this.pre = pre; } } /** * Array with Roman digits. */ private static final RomanDigit[] roman = { new RomanDigit('m', 1000, false), new RomanDigit('d', 500, false), new RomanDigit('c', 100, true), new RomanDigit('l', 50, false), new RomanDigit('x', 10, true), new RomanDigit('v', 5, false), new RomanDigit('i', 1, true) }; /** * Changes an int into a lower case roman number. * @param index the original number * @return the roman number (lower case) */ public static final String getString(int index) { StringBuffer buf = new StringBuffer(); // lower than 0 ? Add minus if (index < 0) { buf.append('-'); index = -index; } // greater than 3000 if (index > 3000) { buf.append('|'); buf.append(getString(index / 1000)); buf.append('|'); // remainder index = index - (index / 1000) * 1000; } // number between 1 and 3000 int pos = 0; while (true) { // loop over the array with values for m-d-c-l-x-v-i RomanDigit dig = roman[pos]; // adding as many digits as we can while (index >= dig.value) { buf.append(dig.digit); index -= dig.value; } // we have the complete number if (index <= 0) { break; } // look for the next digit that can be used in a special way int j = pos; while (!roman[++j].pre) ; // does the special notation apply? if (index + roman[j].value >= dig.value) { buf.append(roman[j].digit).append(dig.digit); index -= dig.value - roman[j].value; } pos++; } return buf.toString(); } /** * Changes an int into a lower case roman number. * @param index the original number * @return the roman number (lower case) */ public static final String getLowerCaseString(int index) { return getString(index); } /** * Changes an int into an upper case roman number. * @param index the original number * @return the roman number (lower case) */ public static final String getUpperCaseString(int index) { return getString(index).toUpperCase(); } /** * Changes an int into a roman number. * @param index the original number * @return the roman number (lower case) */ public static final String getString(int index, boolean lowercase) { if (lowercase) { return getLowerCaseString(index); } else { return getUpperCaseString(index); } } /** * Test this class using this main method. */ public static void main(String[] args) { for (int i = 1; i < 2000; i++) { System.out.println(getString(i)); } } }