/*

* Copyright (c) 2002-2026 Gargoyle Software Inc.

*

* 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

* https://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.

*/

package org.htmlunit.util;

import java.util.Random;

/**

* Unit tests helper.

*

* @author René Schwietzke

* @author Ronald Brill

*/

public final class RandomUtils {

private static final String LOWERCHARS = "abcdefghijklmnopqrstuvwxyz";

private static final String UPPERCHARS = LOWERCHARS.toUpperCase();

private static final String CHARS = LOWERCHARS + UPPERCHARS;

/**

* Private ctor to keep Checkstyle happy

*/

private RandomUtils() {

}

/**

* Fixed length random string of lower case and uppercase chars.

*

* @param random the random number generator

* @param length the length of the resulting string

* @return a random string of the desired length

*/

public static String randomString(final Random random, final int length) {

return randomString(random, length, length);

}

/**

* Variable length random string of lower case and upper case chars.

*

* @param random the random generator

* @param from min length

* @param to max length (inclusive)

* @return a random string

*/

public static String randomString(final Random random, final int from, final int to) {

final int length = random.nextInt(to - from + 1) + from;

final StringBuilder sb = new StringBuilder(to);

for (int i = 0; i < length; i++) {

final int pos = random.nextInt(CHARS.length());

sb.append(CHARS.charAt(pos));

}

return sb.toString();

}

}