RandomUtil.java

/*
 * Copyright 2014 Alex Bennett & Alexander Chauncey
 *
 * 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.
 */

package com.demigodsrpg.util.misc;

import java.util.Random;

public class RandomUtil {
    private static final Random random = new Random();

    /**
     * Generates a random string with a length of <code>length</code>.
     *
     * @param length the length of the generated string.
     * @return String
     */
    public static String generateString(int length) {
        // Set allowed characters - Create new string to fill - Generate the string - Return string
        char[] chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < length; i++) {
            char c = chars[random.nextInt(chars.length)];
            sb.append(c);
        }
        return sb.toString();
    }

    /**
     * Generates a random integer with a length of <code>length</code>.
     *
     * @param length the length of the generated integer.
     * @return Integer
     */
    public static int generateInt(int length) {
        // Set allowed characters - Create new string to fill - Generate the string - Return string
        char[] chars = "0123456789".toCharArray();
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < length; i++) {
            char c = chars[random.nextInt(chars.length)];
            sb.append(c);
        }
        return Integer.parseInt(sb.toString());
    }

    /**
     * Generates an integer with a value between <code>min</code> and <code>max</code>.
     *
     * @param min the minimum value of the integer.
     * @param max the maximum value of the integer.
     * @return Integer
     */
    public static int generateIntRange(int min, int max) {
        return random.nextInt(max - min + 1) + min;
    }

    /**
     * Generates a double with a value between <code>min</code> and <code>max</code>.
     *
     * @param min the minimum value of the integer.
     * @param max the maximum value of the integer.
     * @return Integer
     */
    public static double generateDoubleRange(double min, double max) {
        return (max - min) * random.nextDouble() + min;
    }

    /**
     * Returns a boolean whose value is based on the given <code>percent</code>.
     *
     * @param percent the percent chance for true.
     * @return Boolean
     */
    public static boolean randomPercentBool(double percent) {
        if (percent <= 0.0) return false;
        double roll = generateDoubleRange(0.0, 100.0);
        return roll <= percent;
    }
}