简单demo如下：

import com.google.common.collect.Lists;
import java.util.List;

/**
 * 随机抽奖程序 demo
 * @author: Nemo
 * @date: 2019/1/4.
 */
public class PrizeDraw {

    /**
     * 得到候选人
     * @return
     */
    private static List<String> getPeopleSet(){
        List<String> peoples = Lists.newArrayList();
        peoples.add("张三");
        peoples.add("李四");
        peoples.add("王五");
        peoples.add("周六");
        peoples.add("Nemo");
        peoples.add("Echo");
        peoples.add("乔峰");
        peoples.add("韦小宝");
        return peoples;
    }

    /**
     * 得到随机次序人员列表
     * @return
     */
    private static String[] getRandomPeopleSet(){
        //全集，所有可能中奖的人
        List<String> peoples = getPeopleSet();
        //开始随机抽取,把名单打乱
        String results[] = new String[peoples.size()];
        int size = peoples.size();
        for(int i=0;i<size;i++) {
            int index = (int) (Math.random() * peoples.size());
            String name = peoples.get(index);
            peoples.remove(name);
            results[i] = name;
        }
        return results;
    }

    /**
     * 随机得到一个幸运儿
     * @return
     */
    private static String getFirstPeople(){
        return getRandomPeopleSet()[0];
    }

    /**
     * 得到随机分组
     * @return
     */
    private static List<List<String>> getGroupPeoples(int groupNum){
        String[] randomSet = getRandomPeopleSet();
        List<List<String>> results = Lists.newArrayList();
        for(int i=0;i<randomSet.length;){
            List<String> groups = Lists.newArrayList();
            for(int j=0;j<groupNum;j++){
                if(i>=randomSet.length){
                    break;
                }
                groups.add(randomSet[i]);
                i++;
            }
            if(groups.size()>0) {
                results.add(groups);
            }
        }
        return results;
    }

    /**
     * 测试主函数
     * @param args
     */
    public static void main(String args[]){

        System.out.println("恭喜【" + getFirstPeople()+"】本轮中了大奖！");
        System.out.println();
        System.out.println();

        //分组测试,3人一组
        List<List<String>> groupPeoples = getGroupPeoples(3);
        for(int i=0;i<groupPeoples.size();i++){
            System.out.println("开始展示第"+(i+1)+"组候选人:");
            List<String> group = groupPeoples.get(i);
            for (String name : group) {
                System.out.print("【" + name + "】");
            }
            System.out.println();
        }
    }

}