每5分钟清除掉的项目

您可以创建一个 timer 存储传递时间的变量

long remainingTimeInSeconds = 300; //5 minutes

然后更新您的任务以减少此计时器 20滴答 (20个滴答=1秒钟)。使用更新任务,检查计时器变量,以验证是否应发送消息或是否应清除丢弃:

Bukkit.getScheduler().scheduleSyncRepeatingTask(MyPlugin.getPlugin(), new Runnable() {

    @Override
    public void run() {
        currentTimeInSeconds--;

        switch(remainingTimeInSeconds) {
           case 60:
           case 30:
           case 15:
           case 10:
           case 5:
           case 3:
           case 2:
           case 1:
           //Send message remainingTimeInSeconds seconds left until drops are cleared!
           break;

           case 0:
           clearAllDrops();
           remainingTimeInSeconds = 300; //Reset your timer
           break;             
        }    

    }
}, 20L, 0);