泛型类的动态验证有哪些方法?

我认为正确的方法是为每项成就制定一个验证方法:

public abstract class Achievement {
    //...name, etc
    public boolean isSatisfied(Data byPlayerData);
}

但这并不妨碍您提供一些具体的实现,并使用参数对它们进行配置。

public class ZombieKillingAchievement extends Achievement {
     private final int numKills;
     public ZombieKillingAchievement(String name, int numKills) {
         this.numKills = numKills;
     }
     public boolean isSatisfied(Data userData) {
         return userData.getZombieKills() >= numKills;
     }
}

//...
registerAchievement(new ZombieKillingAchievement("Zombie Master", 100));
registerAchievement(new ZombieKillingAchievement("Zombie Tamer", 50));

//... on user data change
for ( Achievement a : registeredAchievements ) {
    if ( a.isSatisfied() ) {
        //show congratulatory message
    }
}

编辑 strategy pattern .

public class Achievement {
    //...name, etc
    private final AchievementValidator validator;
}

public interface AchievementValidator {
    public boolean isSatisfied(Data userData);
}

当与匿名内部类一起使用时,它几乎使用函数指针

registerAchievement(new Achievement("Zombie Killer", new AchievementValidator() {
    public boolean isSatisfied(Data data) { return data.getZombieKills() >= 50; }
});

Java中的函数指针(通常在任何面向对象语言中)通常被多态对象所取代。