how to shuffle an array in java

/**
 * @author lautturi.com
 * Java example: how to randomize an array in java
 */

import java.util.*;

public class Lautturi {

	public static void main(String[] args) {

		int[] arr = { 1,2,3,4,5,6,7,8,9,10 };
		
		System.out.println("Before shuffle:"+Arrays.toString(arr));
		
		for (int i = 0; i < arr.length; i++) {
            int index = (int) (Math.random() * arr.length);
            int temp = arr[i];
            arr[i] = arr[index];
            arr[index] = temp;
        }
		
		System.out.println("After shuffle:"+Arrays.toString(arr));
	}
}

output:

Before shuffle:[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
After shuffle:[4, 2, 3, 7, 6, 8, 10, 9, 1, 5]