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copied!<p>I decided to code it myself indeed. Use at your own risk <code>:-)</code></p> <pre><code>/* * NumberExpression.java - a simple number expression parser * * Copyright (c) 2010 Michael Schierl * * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither name of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND THE CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * HOLDERS OR THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ package numberexpression; /** * An expression that matches nonnegative numbers. This supports cron-like * expressions, like <code>1,3-6,100-200,666,1000-3000/5,400-/7</code>, * <code>-100,102-</code> or <code>*</code>. Odd or even numbers can be * matched either by cron's step syntax, or by suffixing a simple range * (without step values) with <code>e</code> or <code>o</code>. * * @author Michael Schierl */ public class NumberExpression { private final NumberRange[] ranges; private final int min, max; /** * Create a new {@link NumberExpression}. * * @param pattern * the expression pattern. * @throws IllegalArgumentException * if the pattern is malformed */ public NumberExpression(String pattern) { String[] parts = pattern.toLowerCase().split(",",-1); ranges = new NumberRange[parts.length]; int min = Integer.MAX_VALUE, max = 0; for (int i = 0; i < ranges.length; i++) { String part = parts[i]; try { if (part.equals("*")) { ranges[i] = new NumberRange(0, Integer.MAX_VALUE, 0, 1); } else if (part.matches("\\*/\\d+")) { ranges[i] = new NumberRange(0, Integer.MAX_VALUE, 0, Integer.parseInt(part.substring(2))); } else if (part.matches("\\d+")) { int value = Integer.parseInt(part); ranges[i] = new NumberRange(value, value, 0, 1); } else if (part.matches("\\d*-\\d*")) { String[] limits = part.split("-", -1); int from = limits[0].length() == 0 ? 0 : Integer.parseInt(limits[0]); int to = limits[1].length() == 0 ? Integer.MAX_VALUE : Integer.parseInt(limits[1]); if (to < from) throw new IllegalArgumentException("Invalid pattern: " + part); ranges[i] = new NumberRange(from, to, 0, 1); } else if (part.matches("\\d*-\\d*/\\d+")) { String[] rangeAndModulus = part.split("/", -1); String[] limits = rangeAndModulus[0].split("-", -1); int from = limits[0].length() == 0 ? 0 : Integer.parseInt(limits[0]); int to = limits[1].length() == 0 ? Integer.MAX_VALUE : Integer.parseInt(limits[1]); int modulus = Integer.parseInt(rangeAndModulus[1]); if (to < from) throw new IllegalArgumentException("Invalid pattern: " + part); ranges[i] = new NumberRange(from, to, from % modulus, modulus); } else if (part.matches("\\d*-\\d*[eo]")) { String[] limits = part.substring(0, part.length() - 1).split("-", -1); int from = limits[0].length() == 0 ? 0 : Integer.parseInt(limits[0]); int to = limits[1].length() == 0 ? Integer.MAX_VALUE : Integer.parseInt(limits[1]); if (to < from) throw new IllegalArgumentException("Invalid pattern: " + part); ranges[i] = new NumberRange(from, to, part.charAt(part.length() - 1) == 'o' ? 1 : 0, 2); } else { throw new IllegalArgumentException("Invalid pattern: " + part); } max = Math.max(max, ranges[i].getMax()); min = Math.min(min, ranges[i].getMin()); } catch (NumberFormatException ex) { throw new IllegalArgumentException("Invalid pattern: " + part); } } this.max = max; this.min = min; } /** * Check whether this number expression matches the given number. * * @param number * the number to check against * @return whether the expression matches the number */ public boolean matches(int number) { if (number < min || number > max) return false; for (int i = 0; i < ranges.length; i++) { if (ranges[i].matches(number)) return true; } return false; } /** * Return the minimum number that can be matched. */ public int getMinimum() { return min; } /** * Return the maximum number that can be matched. */ public int getMaximum() { return max; } private static class NumberRange { private final int min, max, remainder, modulus; NumberRange(int min, int max, int remainder, int modulus) { this.min = min; this.max = max; this.remainder = remainder; this.modulus = modulus; } boolean matches(int number) { return number >= min && number <= max && number % modulus == remainder; } int getMin() { return min; } int getMax() { return max; } } } </code></pre>

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