Java中随机获取List的集合的元素

实现代码如下：

List<VCard> vcards = new ArrayList<>();
// add some elements to vcards
...

// 随机 100
Random r = new Random();
List<VCard> randomList = new ArrayList<>();
while (randomList.size() < 100){
    randomList.add(vcards.get(r.nextInt(vcards.size())));
}

References

1. How to get a random element from a list with stream api?；