4

我对设计模式比较陌生，在下面的示例中，我使用了我认为是策略模式的东西。但是，我在一些（不是全部）具体策略中重复自己，想知道有没有办法避免这种情况？注意 ACommand 和 CCommand 在做一些独特的事情之前有相同的代码。

public interface Command 
{
    public boolean execute(CommandSender sender, String[] args);
    public String getName();
    //...
}

public abstract class PlayerCommand implements Command 
{
    protected BukkitPlugin plugin = BukkitPlugin.getInstance();

    private String name;
    //...

    public PlayerCommand(String name) 
    {
        this.name = name;
    }

    public String getName() 
    {
        return this.name;
    }

    //...
}

指令

    public class ACommand extends PlayerCommand
    {
        public ACommand()
        {
            super("A");
        }

        public boolean execute(CommandSender sender, String[] args)
        {
            Player player = (Player) sender;
            PlayerInventory inventory = player.getInventory();
            ItemStack itemInHand = inventory.getItemInHand();

            if(itemInHand.getType() != Material.COMPASS)
            {
                sender.sendMessage("You must be holding a phone to use this command");
                return true;
            }

            int id = itemInHand.getDurability();

            MobilePhoneManager phoneManager = plugin.getMobilePhoneManager();       
            boolean isMobilePhone = phoneManager.isMobilePhone(id);

            if(!isMobilePhone)
            {
                sender.sendMessage("You must be holding a mobile phone to use this command");
                return true;
            }

            //DO SOMETHING UNIQUE HERE
        }
}

B命令

public class BCommand extends PlayerCommand
        {
            public BCommand()
            {
                super("B");
            }

            public boolean execute(CommandSender sender, String[] args)
            {
                //SOMETHING ELSE
            }
    }

C命令

    public class CCommand extends PlayerCommand
    {
        public CCommand()
        {
            super("C");
        }

        public boolean execute(CommandSender sender, String[] args)
        {
            Player player = (Player) sender;
            PlayerInventory inventory = player.getInventory();
            ItemStack itemInHand = inventory.getItemInHand();

            if(itemInHand.getType() != Material.COMPASS)
            {
                sender.sendMessage("You must be holding a phone to use this command");
                return true;
            }

            int id = itemInHand.getDurability();

            MobilePhoneManager phoneManager = plugin.getMobilePhoneManager();       
            boolean isMobilePhone = phoneManager.isMobilePhone(id);

            if(!isMobilePhone)
            {
                sender.sendMessage("You must be holding a mobile phone to use this command");
                return true;
            }

            //DO SOMETHING UNIQUE HERE
        }
}
4

2 回答 2

7

您可以使用模板模式ACommand作为和之间的公共基类的基础CCommand。基类中的模板方法将保存公共代码，然后调用 ( abstract) 方法doSomethingUnique()。

于 2013-03-12T20:47:09.680 回答
0

安德烈在所有方面都是正确的。您正在使用命令模式，您只需要稍微调整您的界面以包含有关命令当前是否处于可以执行的状态的一些概念

bool canExecute();
boll canExecute(args)

但是，您通常看不到 execute 方法返回任何内容。

HTH，
绿柱石

于 2013-03-13T05:13:14.300 回答