/*
* Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
*
* 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.hazelcast.util;
import java.util.Random;
/**
* User: ahmetmircik
* Date: 10/7/13
* Time: 12:27 PM
*/
public final class RandomPicker {
private static Random randomNumberGenerator;
private RandomPicker() {
}
private static synchronized void initRNG() {
if (randomNumberGenerator == null) {
randomNumberGenerator = new Random();
}
}
/**
* Returns a pseudorandom, uniformly distributed int value between 0 (inclusive)
* and the specified value (exclusive), drawn from this random number generator's sequence.
* Starts the random number generator sequence if it has not been initialized.
*
* @param n the specified value
* @return a value between 0 (inclusive) and the specified value (exclusive).
*/
public static int getInt(int n) {
if (randomNumberGenerator == null) {
initRNG();
}
return randomNumberGenerator.nextInt(n);
}
/**
* Return a pseudorandom, uniformly distributed in value between the low value (inclusive) and
* the high value (exclusive), drawn from this random number generator's sequence.
* Starts the random number generator sequence if it has not been initialized.
*
* @param low lowest value of the range (inclusive)
* @param high highest value of the range (exclusive)
* @return a value between the specified low (inclusive) and high value (exclusive).
*/
public static int getInt(int low, int high) {
return getInt(high - low) + low;
}
}