randomizer.java

来自「一个ＪＡＶＡ原程序」· Java 代码 · 共 37 行

package edu.zsu.zouang.util;

import java.util.Random;

public class Randomizer {
	private int lower;
	private int upper;
	
	private static Random random = new Random();
	
	public Randomizer(int lower, int upper){
		if(upper <= lower){
			throw new IllegalStateException("Upper is smaller than lower!");
		}
		this.lower = lower;
		this.upper = upper;
	}
	public Double nextDouble(){
		return Double.valueOf(lower + (upper - lower) * random.nextDouble());
	}
	
	public Integer nextInteger(){
		return Integer.valueOf(lower +random.nextInt(upper - lower));
	}
	
	public char[] nextBitArray(int length){
		if(length <= 0){
			throw new IllegalStateException("Length is less than ZERO!");
		}
		char[] temp = new char[length];
		for(int i = 0; i < length ; i++){
			temp[i] = random.nextBoolean() ? '1' : '0';
		}
		return temp;
	}
}