java - 连续生成随机枚举值而不两次获得相同的值

Question

我有一个要随机化的枚举团队。所以我有:

public enum Teams { TEAM1, TEAM2, TEAM3, TEAM4, TEAM5, TEAM6; }

然后我有一个随机方法来随机生成值:

public static Teams getRandomTeam() {
    return Teams.values()[(int) (Math.random() * Teams.values().length)];
}

这确实会返回一个随机生成的团队，但是我需要，一旦生成了一个团队，比如 TEAM2，它就不能再次生成。

我正在使用:

System.out.println("The team is " + getRandomTeam());
System.out.println("The team is " + getRandomTeam());
System.out.println("The team is " + getRandomTeam());
System.out.println("The team is " + getRandomTeam());
System.out.println("The team is " + getRandomTeam());
System.out.println("The team is " + getRandomTeam());

(我知道这是错误的，因为它一遍又一遍地调用方法。

在我运行程序的那一刻，输出可能是:

团队是:TEAM2

团队是:TEAM2

团队是:TEAM4

团队是:TEAM2

团队是:TEAM3

团队是:TEAM2

但我需要我的程序只输出一次枚举值。谢谢

Answer 1

只需使用 Collections.shuffle .

List<Team> teams = new ArrayList<>();
Collections.addAll(teams, Team.values());
Collections.shuffle(teams);