com.cloudhopper.commons.util.RandomUtil Maven / Gradle / Ivy
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 http://twitter.com/jjlauer)
*/
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);
}
}