Arakne / Araknemu

 * This file is part of Araknemu.

 *

 * Araknemu is free software: you can redistribute it and/or modify

 * it under the terms of the GNU Lesser General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * Araknemu 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 Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with Araknemu.  If not, see <https://www.gnu.org/licenses/>.

 *

 * Copyright (c) 2017-2019 Vincent Quatrevieux

 */

package fr.quatrevieux.araknemu.util;

import org.checkerframework.checker.index.qual.NonNegative;

import org.checkerframework.common.value.qual.MinLen;

import java.util.Random;

/**

 * Random generation for strings

 */

public final class RandomStringUtil {

    private final Random random;

    private final @MinLen(1) String charset;

    /**

     * Create instance

     * @param random The random generator instance

     * @param charset  The charset to use

     */

    /**

     * Generate the random string

     *

     * @param length The required string length

     */

    public String generate(@NonNegative int length) {

        final char[] buffer = new char[length];

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

            buffer[i] = charset.charAt(random.nextInt(charset.length()));

        }

        return new String(buffer);

    }

}