content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.alibaba.nacos.client.naming.utils;
  
  import java.util.Random;
  
  /**
   * <p><code>RandomUtils</code> is a wrapper that supports all possible {@link java.util.Random} methods via the {@link
   * java.lang.Math#random()} method and its system-wide <code>Random</code> object.
   *
   * @author Gary D. Gregory
   * @version $Id: RandomUtils.java 906320 2010-02-04 01:41:10Z sebb $
   * @since 2.0
   */
  public class RandomUtils {
  
      /**
       * An instance of {@link JvmRandom}.
       */
      private static final Random JVM_RANDOM = new JvmRandom();
  
      // should be possible for JVM_RANDOM?
      //    public static void nextBytes(byte[]) {
      //    public synchronized double nextGaussian();
      //    }
  
      /**
       * <p>Returns the next pseudorandom, uniformly distributed int value from the Math.random() sequence.</p> <b>N.B.
       * All values are >= 0.<b>
       *
       * @return the random int
       */
      public static int nextInt() {
          return nextInt(JVM_RANDOM);
      }
  
      /**
       * <p>Returns the next pseudorandom, uniformly distributed int value from the given <code>random</code>
       * sequence.</p>
       *
       * @param random the Random sequence generator.
       * @return the random int
       */
      public static int nextInt(Random random) {
          return random.nextInt();
      }
  
      /**
       * <p>Returns a pseudorandom, uniformly distributed int value between <code>0</code> (inclusive) and the specified
       * value (exclusive), from the Math.random() sequence.</p>
       *
       * @param n the specified exclusive max-value
       * @return the random int
       */
      public static int nextInt(int n) {
          return nextInt(JVM_RANDOM, n);
      }
  
      /**
       * <p>Returns a pseudorandom, uniformly distributed int value between <code>0</code> (inclusive) and the specified
       * value (exclusive), from the given Random sequence.</p>
       *
       * @param random the Random sequence generator.
       * @param n      the specified exclusive max-value
       * @return the random int
       */
      public static int nextInt(Random random, int n) {
          // check this cannot return 'n'
          return random.nextInt(n);
      }
  
      /**
       * <p>Returns the next pseudorandom, uniformly distributed long value from the Math.random() sequence.</p> <b>N.B.
       * All values are >= 0.<b>
       *
       * @return the random long
       */
      public static long nextLong() {
          return nextLong(JVM_RANDOM);
      }
  
      /**
       * <p>Returns the next pseudorandom, uniformly distributed long value from the given Random sequence.</p>
       *
       * @param random the Random sequence generator.
       * @return the random long
       */
      public static long nextLong(Random random) {
          return random.nextLong();
      }
  
      /**
       * <p>Returns the next pseudorandom, uniformly distributed boolean value from the Math.random() sequence.</p>
       *
       * @return the random boolean
       */
      public static boolean nextBoolean() {
          return nextBoolean(JVM_RANDOM);
      }
  
      /**
       * <p>Returns the next pseudorandom, uniformly distributed boolean value from the given random sequence.</p>
       *
       * @param random the Random sequence generator.
       * @return the random boolean
       */
      public static boolean nextBoolean(Random random) {
          return random.nextBoolean();
      }
  
      /**
       * <p>Returns the next pseudorandom, uniformly distributed float value between <code>0.0</code> and <code>1.0</code>
       * from the Math.random() sequence.</p>
       *
       * @return the random float
       */
      public static float nextFloat() {
          return nextFloat(JVM_RANDOM);
      }
  
      /**
       * <p>Returns the next pseudorandom, uniformly distributed float value between <code>0.0</code> and <code>1.0</code>
       * from the given Random sequence.</p>
       *
       * @param random the Random sequence generator.
       * @return the random float
       */
      public static float nextFloat(Random random) {
          return random.nextFloat();
      }
  
      /**
       * <p>Returns the next pseudorandom, uniformly distributed float value between <code>0.0</code> and <code>1.0</code>
       * from the Math.random() sequence.</p>
       *
       * @return the random double
       */
      public static double nextDouble() {
          return nextDouble(JVM_RANDOM);
      }
  
      /**
       * <p>Returns the next pseudorandom, uniformly distributed float value between <code>0.0</code> and <code>1.0</code>
       * from the given Random sequence.</p>
       *
       * @param random the Random sequence generator.
       * @return the random double
       */
      public static double nextDouble(Random random) {
          return random.nextDouble();
      }
  
  }
  