生成8位随机不重复的数字编号的方法

package com.jjinfo.common.util;
import java.util.Arrays;
import java.util.Random;


public class RandomNumberGenerator {


public static String generateNumber() {
String no="";
//初始化备选数组
int[] defaultNums = new int[10];
for (int i = 0; i < defaultNums.length; i++) {
defaultNums[i] = i;
}

Random random = new Random();
int[] nums = new int[LENGTH];
//默认数组中可以选择的部分长度
int canBeUsed = 10;
//填充目标数组
for (int i = 0; i < nums.length; i++) {
//将随机选取的数字存入目标数组
int index = random.nextInt(canBeUsed);
nums[i] = defaultNums[index];
//将已用过的数字扔到备选数组最后，并减小可选区域
swap(index, canBeUsed - 1, defaultNums);
canBeUsed--;
}
if (nums.length>0) {
for (int i = 0; i < nums.length; i++) {
no+=nums[i];
}
}

return no;
}
private static final int LENGTH = 8;

private static void swap(int i, int j, int[] nums) {
int temp = nums[i];
nums[i] = nums[j];
nums[j] = temp;
}

public static String generateNumber2() {
String no="";
int num[]=new int[8];
int c=0;
for (int i = 0; i < 8; i++) {
num[i] = new Random().nextInt(10);
c = num[i];
for (int j = 0; j < i; j++) {
if (num[j] == c) {
i--;
break;
}
}
}
if (num.length>0) {
for (int i = 0; i < num.length; i++) {
no+=num[i];
}
}
return no;
}

public static void main(String[] args) {
for (int i = 0; i < 10; i++) {
// System.out.println(generateNumber());
System.out.println(generateNumber2());
}
}
}