com.azure.cosmos.implementation.apachecommons.lang.RandomUtils Maven / Gradle / Ivy
/*
* 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.
*/
/*
* Portions Copyright (c) Microsoft Corporation
*/
package com.azure.cosmos.implementation.apachecommons.lang;
import java.util.Random;
public class RandomUtils {
/**
* Random object used by random method. This has to be not local to the
* random method so as to not return the same value in the same millisecond.
*/
private static final Random RANDOM = new Random();
/**
*
* {@code RandomUtils} instances should NOT be constructed in standard
* programming. Instead, the class should be used as
* {@code RandomUtils.nextBytes(5);}.
*
*
*
* This constructor is public to permit tools that require a JavaBean
* instance to operate.
*
*/
private RandomUtils() {
super();
}
/**
*
* Returns a random integer within the specified range.
*
*
* @param startInclusive
* the smallest value that can be returned, must be non-negative
* @param endExclusive
* the upper bound (not included)
* @throws IllegalArgumentException
* if {@code startInclusive > endExclusive} or if
* {@code startInclusive} is negative
* @return the random integer
*/
public static int nextInt(final int startInclusive, final int endExclusive) {
Validate.isTrue(endExclusive >= startInclusive,
"Start value must be smaller or equal to end value.");
Validate.isTrue(startInclusive >= 0, "Both range values must be non-negative.");
if (startInclusive == endExclusive) {
return startInclusive;
}
return startInclusive + RANDOM.nextInt(endExclusive - startInclusive);
}
/**
* Returns a random int within 0 - Integer.MAX_VALUE
*
* @return the random integer
*/
public static int nextInt() {
return nextInt(0, Integer.MAX_VALUE);
}
}