Java数组打乱顺序的方法

package com.webkfa.test;

import java.io.IOException;
import java.util.Random;
public class Test {
	public static void main(String[] args) throws IOException{
		String[] arr={"1","2","3","4","5","6","7"};
		String[] newarr = changePosition(arr);
		for (int i = 0; i < newarr.length; i++) {
			System.out.println(newarr[i]);
		}
	}
	//打乱数组开始
	//重排序
	public static String[] changePosition(String arr[]){
		if(arr==null || arr.length==0){
			return arr;
		}
		Random random = new Random();
		for(int index=arr.length-1; index>=0; index--) {
			//从0到index处之间随机取一个值，跟index处的元素交换
			exchange(arr,random.nextInt(index+1), index);
		}
		return arr; 
	}
	//交换位置
	private static void exchange(String arr[],int p1, int p2) {
		String temp = arr[p1];
		arr[p1] = arr[p2];
		arr[p2] = temp;
	}
}