io.virtdata.functional.RandomRangedToInt Maven / Gradle / Ivy
/*
*
* Copyright 2015 Jonathan Shook
*
* 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 io.virtdata.functional;
import org.apache.commons.math3.random.MersenneTwister;
import java.util.function.LongFunction;
public class RandomRangedToInt implements LongFunction {
private MersenneTwister theTwister = new MersenneTwister(System.nanoTime());
private long min;
private long max;
private long _length;
public RandomRangedToInt(int min, int max) {
if (max<=min) {
throw new RuntimeException("max must be >= min");
}
this.min = min;
this.max = max;
this._length = max - min;
}
public String toString() {
return getClass().getSimpleName() + ":" + min + ":" + max;
}
@Override
public Integer apply(long operand) {
long value = Math.abs(theTwister.nextLong());
value %= _length;
value += min;
return (int) value;
}
}