java - 从扩展另一个对象的对象调用方法(不是您想象的那样)

Question

我有一个问题。如何在对象的减速中放置一个方法？让我解释。我正在制作的是 Minecraft 网络。我们提供的所有游戏都是他们自己的类别。

示例:CaptureTheFlag 是它自己的对象，但它扩展了一个名为 arena 的类。

每个游戏类别都扩展了竞技场类别。因此，当制作这些游戏时，它们会被添加到 HashMap (double、a​​rena)中。当我迭代这些寻找特定的游戏模式时，我需要能够调用该游戏模式的方法以便玩家加入。

示例:CaptureTheFlag.join(player)

每个游戏都有相同的称为 join 的方法和相同的参数，但每个游戏都会执行不同的操作，因为这些是不同的游戏。因此，当我迭代 HashMap 并找到特定值(arena)时，我希望能够像这样调用捕获标志连接方法:

Iterator<Entry<Double, Arena>> it = 
ArenaManager.local_arenas.entrySet().iterator();
    while (it.hasNext()) {
        Entry<Double, Arena> pair = it.next();
        if (pair.getKey().doubleValue() == game_mode) {



                pair.getValue().join(player)

        }

    }

请注意，这不是完整的代码。 (我正在手机上输入此内容)

有没有人有解决办法？

Answer 1

解决方案1:使用抽象方法:

import java.util.HashMap;
import java.util.Map;

public class Foo {

    static class Player {
        private final String name;

        Player(final String name) {
            this.name = name;
        }

        @Override
        public String toString() {
            return name;
        }
    }

    static abstract class Arena {
        abstract void join(Player player);
    }

    static class CaptureTheFlagArena extends Arena {

        @Override
        void join(final Player player) {
            System.out.printf("%s is joining a capture the flag game!%n", player);
        }
    }

    static class DominationArena extends Arena {

        @Override
        void join(final Player player) {
            System.out.printf("%s is joining a domination arena!%n", player);
        }
    }

    /**
     * Prints:
     * Bob is joining a domination arena!
     * Bob is joining a capture the flag game!
     */
    public static void main(String[] args) {
        final Map<Double, Arena> map = new HashMap<>();
        map.put(7d, new CaptureTheFlagArena());
        map.put(6d, new DominationArena());
        for (Map.Entry<Double, Arena> entry : map.entrySet()) {
            entry.getValue().join(new Player("Bob"));
        }
    }
}

解决方案 2:使用接口(interface):

import java.util.HashMap;
import java.util.Map;

public class Foo {

    static class Player {
        private final String name;

        Player(final String name) {
            this.name = name;
        }

        @Override
        public String toString() {
            return name;
        }
    }

    interface Joinable {
        void join(Player player);
    }

    static abstract class Arena implements Joinable {

    }

    static class CaptureTheFlagArena extends Arena {

        @Override
        public void join(final Player player) {
            System.out.printf("%s is joining a capture the flag game!%n", player);
        }
    }

    static class DominationArena extends Arena {

        @Override
        public void join(final Player player) {
            System.out.printf("%s is joining a domination arena!%n", player);
        }
    }

    static class ChessGame implements Joinable {

        @Override
        public void join(final Player player) {
            System.out.printf("%s is joining a chess game!%n", player);
        }
    }

    /**
     * Prints:
     * Bob is joining a domination arena!
     * Bob is joining a capture the flag game!
     * Bob is joining a chess game!
     */
    public static void main(String[] args) {
        final Map<Double, Joinable> map = new HashMap<>();
        map.put(7d, new CaptureTheFlagArena());
        map.put(6d, new DominationArena());
        map.put(2d, new ChessGame());
        for (Map.Entry<Double, Joinable> entry : map.entrySet()) {
            entry.getValue().join(new Player("Bob"));
        }
    }
}