java - 如何使用观察者模式通过线程进行文件监视?

标签 java observer-pattern java-threads file-monitoring

我正在尝试在我制作的游戏中实现观察者模式。当使用线程在战区文件中创建恶棍时,我想使用观察者模式使用线程创建英雄并将其添加到同一文件中。反派和英雄是使用工厂方法模式创建的。我不确定如何将我的 HeroCreationMain 类链接到观察者模式类。

反派创作

public class VillianCreationMain {

private static Villian villian;

public static void main(String[] args, int userInput) throws IOException {

    String fileName = null;

    Random randomVillian = new Random();

    int amountOfVillians = userInput;

    if (amountOfVillians < 7) {

        for (int x = 0; x < amountOfVillians; x++) {

            int randomGenerator = randomVillian.nextInt(6);

                for (int i = 0; i < 5; i++) {

                    if (randomGenerator == 0 ) {

                        setVillian(new FlyingVillian());

                    }

                    else if (randomGenerator == 1) {

                        setVillian(new StrongVillian());

                    }

                    else if (randomGenerator == 2) {

                        setVillian(new FastVillian());

                    }

                    else if (randomGenerator == 3) {

                        setVillian(new SmartVillian());

                    }

                    else if (randomGenerator == 4) {

                        setVillian(new FireVillian());

                    }

                    else if (randomGenerator == 5) {

                        setVillian(new IceVillian());

                    }

                        try {

                            writeToFile(getVillian(), i, fileName);
                        }
                        catch (IOException e) {

                            System.out.println(e.getMessage());
                        }

                    }

                VillianThreads t1 = new VillianThreads(VillianCreationMain.getVillian());

                t1.start();

                }

            }

    else {

            System.out.println("Please enter a value of less than 7");
    }
}

public static void writeToFile(Villian villian, int amountOfVillians, String fileName) throws IOException {

    for(int x = 0; x < amountOfVillians; x++) {

    //  String parsedInt = Integer.toString(x);

        fileName = "battle-zone.ser";

        FileOutputStream file = new FileOutputStream(fileName);
        ObjectOutputStream oos = new ObjectOutputStream(file);

        oos.writeObject(villian);

        file.close();
        oos.close();
    }
}

public static Villian getVillian() {
    return villian;
}

public static void setVillian(Villian villian) {
    VillianCreationMain.villian = villian;
}

}

英雄创建

public class HeroCreationMain {

private static Hero hero = null;

public static void main(String[] Hero) {

    EnemyStatus enemyStatus = new EnemyStatus();

    VillianObserver observer1 = new VillianObserver(enemyStatus);

}

public static void readFile() throws IOException, ClassNotFoundException {

    @SuppressWarnings("resource")
    ObjectInputStream ois = new ObjectInputStream (new FileInputStream("battle-zone.ser"));

    Villian targetVillian = (Villian) ois.readObject();
    System.out.println(targetVillian + " is being attacked by a hero!");
}

public static Hero getHero() {
    return hero;
}

public static void setHero(Hero hero) {
    HeroCreationMain.hero = hero;
}
}

观察者

public interface Observer {

public void update(boolean enemyPresent);

}

public interface Subject {

public void register(Observer o);
public void unregister(Observer o);
public void notifyObserver();

}

可观察

public class VillianObserver implements Observer {

private boolean enemyPresent;
private static int heroIDTracker;
private int heroID;
private Subject villianObserver;

public VillianObserver(Subject villianObserver) {

    this.villianObserver = villianObserver;
    this.heroID = ++heroIDTracker;
    System.out.println("New Observer " + this.heroID);
    villianObserver.register(this);
}

@Override
public void update(boolean enemyPresent) {

    this.enemyPresent = enemyPresent;
    printResult();
}

public void printResult() {

    System.out.println(heroID + " " + enemyPresent);
}

}

敌人状态

import java.util.ArrayList;

public class EnemyStatus implements Subject {

private ArrayList<Observer> observers;
private boolean enemyPresent;

public EnemyStatus() {

    // Creates an ArrayList to hold all observers

    observers = new ArrayList<Observer>();

}

@Override
public void register(Observer newObserver) {

    observers.add(newObserver);

}

@Override
public void unregister(Observer deleteObserver) {

    // Get the index of the observer to delete

    int heroIndex = observers.indexOf(deleteObserver);

    // Print out message (Have to increment index to match  

    System.out.println("Observer " + (heroIndex+1) + " deleted");        

    // Removes observer from the ArrayList

    observers.remove(heroIndex);


}

@Override
public void notifyObserver() {

    for(Observer observer : observers) {

        observer.update(enemyPresent);
    }

}

public void setEnemyStatus(boolean enemyPresent) {

    this.enemyPresent = enemyPresent;
    notifyObserver();

}

}  

最佳答案

JNotify 是用于观察文件系统上的文件更改的 Java 库。

一条建议:当您刚开始使用时,对象(输入/输出)流很容易,但它们会导致您走上一条毁灭之路。对象很容易被错误版本化。使用文本编辑器检查目标文件也相对困难。我建议您尝试使用不同的数据格式(例如 JSON)。

关于java - 如何使用观察者模式通过线程进行文件监视?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/58845456/

上一篇:java - 快速排序出界

下一篇:Java 类到 XSD

相关文章:

java - 何时在Java中通过ArrayList使用LinkedList?

java - 停止线程

java - 在构造函数中泄漏它

ios - 键值观察外观类上的静态 NSDictionary

java - 尽管条件值发生变化,但循环并未停止

java - 同步块(synchronized block)

java - java中的foreach循环用于字典

java - 什么是序列化和可分包

Netbeans 关于事件注入(inject)的警告

java - 在 Java 中创建太多线程