java - 错误 getPlayer(args[0]);

Question

我编写了这段代码，如果您在 MC 中输入:/gmspec，我应该将您的游戏模式设置为观众模式。但它唯一说的是:“尝试执行此命令时发生内部错误。”。在控制台中它显示: arrayindexoutofboundsException:0...请帮忙，我不知道问题是什么...

    if (commandLabel.equalsIgnoreCase("gmspec")) {


        Player p = (Player) sender;
        Player target = Bukkit.getServer().getPlayer(args[0]);


        if (args.length == 0) {
            p.setGameMode(GameMode.SPECTATOR);
            p.sendMessage(ChatColor.GREEN + "Your own gamemode has been changed!");
            return true;
        }

        if (target == null) {
            p.sendMessage(ChatColor.RED + "The player " + target.getName() + " is not online!");
            return true;

        }
        target.setGameMode(GameMode.SPECTATOR);
        target.sendMessage(ChatColor.GREEN + "Your gamemode is set to Spectator mode. You are not a banaan that just tries every command without any permission...");

        if (sender.hasPermission("gamemode.spectator")) {

            p.sendMessage(ChatColor.RED + "You banaan. Y u still try? U no permission has u dumb shit");
        }
        if (sender instanceof ConsoleCommandSender) {


        }


    }
    return true;
}

Answer 1

您的问题是您在尝试获取参数之后检查它们的长度。在尝试获取参数之前，您必须确保存在一个或多个参数，否则您将得到 ArrayIndexOutOfBoundsException

此外，在将命令发送者转换为 Player 之前，您需要检查命令发送者是否确实是 Player。如果您不这样做，您将无法从播放器之外的任何地方运行该命令。

要解决此问题，您可以将每个 p.sendMessage() 替换为 sender.sendMessage()，并且仅将 sender 转换为播放器 if 发送者实例播放器

所以，你的代码可能看起来像这样

if(commandLabel.equalsIgnoreCase("gmspec")){
    if(args.length == 0 && sender instanceof Player){//check if the sender is a Player
        Player p = (Player) sender; 

        p.setGameMode(GameMode.SPECTATOR);
        p.sendMessage(ChatColor.GREEN + "Your own gamemode has been changed!");

        return true;
    }
    else{
        Player target = Bukkit.getServer().getPlayer(args[0]);

        //the rest of the code
    }
}