package com.cloudhopper.commons.util; /* * #%L * ch-commons-util * %% * Copyright (C) 2012 Cloudhopper by Twitter * %% * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * #L% */ // java imports import java.util.Random; /** * Utility class for using and generating random object such as strings. Useful * for generating things like random passwords, verification codes, etc. * * @author joelauer (twitter: @jjlauer or <a href="http://twitter.com/jjlauer" target=window>http://twitter.com/jjlauer</a>) */ public class RandomUtil { private static final String chars = "abcdefghijklmonpqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; private static Random random = new Random(); /** * Creates a random string using only lowercase ascii letters, uppercase * ascii letters, and digits. This method internally uses a static instance * of a Random() object. * @param length The length of random string to generate * @return A new random string with a length specified in the length parameter */ public static String generateString(int length) { char[] buf = new char[length]; for (int i = 0; i < buf.length; i++) { buf[i] = chars.charAt(random.nextInt(chars.length())); } return new String(buf); } }