src/main/java/org/apache/accumulo/testing/stress/RandomWithinRange.java

/*
 * 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
 *
 *   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.apache.accumulo.testing.stress;

import static com.google.common.base.Preconditions.checkArgument;

import java.util.Random;

/**
 * Class that returns positive integers between some minimum and maximum.
 *
 */
public class RandomWithinRange {
  private final Random random;
  private final int min, max;

  public RandomWithinRange(int seed, int min, int max) {
    this(new Random(seed), min, max);
  }

  public RandomWithinRange(Random random, int min, int max) {
    checkArgument(min > 0, "Min must be positive.");
    checkArgument(max >= min, "Max must be greater than or equal to min.");
    this.random = random;
    this.min = min;
    this.max = max;
  }

  public int next() {
    if (min == max) {
      return min;
    } else {
      // we pick a random number that's between 0 and (max - min), then
      // add
      // min as an offset to get a random number that's [min, max)
      return random.nextInt(max - min) + min;
    }
  }

  public byte[] next_bytes() {
    byte[] b = new byte[next()];
    random.nextBytes(b);
    return b;
  }
}