java List随机排序 Collections.shuffle()

使用 Collections.shuffle（）

public static void main(String[] args) {
        List<String> list = new ArrayList<String>();
        list.add("a");
        list.add("b");
        list.add("c");
        list.add("d");
        list.add("e");
        list.add("f");
        list.add("g");
        System.out.println("随机前：" + JSON.toJSONString(list));
        Collections.shuffle(list);
        System.out.println("第一次随机后：" + JSON.toJSONString(list));
        Collections.shuffle(list);
        System.out.println("第二次随机后：" + JSON.toJSONString(list));
    }

结果展示：

随机前：["a","b","c","d","e","f","g"]
第一次随机后：["c","d","g","f","e","b","a"]
第二次随机后：["a","b","g","d","e","c","f"]