com.dexcoder.commons.utils.RandomUtils Maven / Gradle / Ivy
package com.dexcoder.commons.utils;
import java.util.Random;
/**
* 本类来源于apache-commons-lang > RandomUtils
*
* Created by liyd on 2015-12-4.
*/
public class RandomUtils {
/**
*/
public static final Random JVM_RANDOM = new Random();
// should be possible for JVM_RANDOM?
// public static void nextBytes(byte[]) {
// public synchronized double nextGaussian();
// }
/**
* Returns the next pseudorandom, uniformly distributed int value
* from the Math.random() sequence.
* N.B. All values are >= 0.
*
* @return the random int
*/
public static int nextInt() {
return nextInt(JVM_RANDOM);
}
/**
* 指定区间的随机数
*
* @param min
* @param max
* @return
*/
public static int nextInt(int min, int max) {
return JVM_RANDOM.nextInt((max - min) + 1) + min;
}
/**
* Returns the next pseudorandom, uniformly distributed int value
* from the given random sequence.
*
* @param random the Random sequence generator.
* @return the random int
*/
public static int nextInt(Random random) {
return random.nextInt();
}
/**
* Returns a pseudorandom, uniformly distributed int value
* between 0 (inclusive) and the specified value
* (exclusive), from the Math.random() sequence.
*
* @param n the specified exclusive max-value
* @return the random int
*/
public static int nextInt(int n) {
return nextInt(JVM_RANDOM, n);
}
/**
* Returns a pseudorandom, uniformly distributed int value
* between 0 (inclusive) and the specified value
* (exclusive), from the given Random sequence.
*
* @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);
}
/**
* Returns the next pseudorandom, uniformly distributed long value
* from the Math.random() sequence.
* N.B. All values are >= 0.
*
* @return the random long
*/
public static long nextLong() {
return nextLong(JVM_RANDOM);
}
/**
* Returns the next pseudorandom, uniformly distributed long value
* from the given Random sequence.
*
* @param random the Random sequence generator.
* @return the random long
*/
public static long nextLong(Random random) {
return random.nextLong();
}
/**
* Returns the next pseudorandom, uniformly distributed boolean value
* from the Math.random() sequence.
*
* @return the random boolean
*/
public static boolean nextBoolean() {
return nextBoolean(JVM_RANDOM);
}
/**
* Returns the next pseudorandom, uniformly distributed boolean value
* from the given random sequence.
*
* @param random the Random sequence generator.
* @return the random boolean
*/
public static boolean nextBoolean(Random random) {
return random.nextBoolean();
}
/**
* Returns the next pseudorandom, uniformly distributed float value
* between 0.0 and 1.0 from the Math.random()
* sequence.
*
* @return the random float
*/
public static float nextFloat() {
return nextFloat(JVM_RANDOM);
}
/**
* Returns the next pseudorandom, uniformly distributed float value
* between 0.0 and 1.0 from the given Random
* sequence.
*
* @param random the Random sequence generator.
* @return the random float
*/
public static float nextFloat(Random random) {
return random.nextFloat();
}
/**
* Returns the next pseudorandom, uniformly distributed float value
* between 0.0 and 1.0 from the Math.random()
* sequence.
*
* @return the random double
*/
public static double nextDouble() {
return nextDouble(JVM_RANDOM);
}
/**
* Returns the next pseudorandom, uniformly distributed float value
* between 0.0 and 1.0 from the given Random
* sequence.
*
* @param random the Random sequence generator.
* @return the random double
*/
public static double nextDouble(Random random) {
return random.nextDouble();
}
}