有没有办法让currentclass指向刚读入Java的新对象Serializable？

Question

我正在尝试读取用于社交网络模拟的对象。读取方法使用 Java Serializable。代码如下所示：

public class SocialNetwork  implements Serializable{

// lots of fields

public SocialNetwork(){
//lots of inilization
} 
    public void writethisObject() throws IOException{
            ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream("Simulation.bin"));
            objectOutputStream.writeObject(this);
        }

        public void readfromObject(File f) throws IOException, ClassNotFoundException{
            ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream(f));
            SocialNetwork newSocialNetwork = (SocialNetwork) objectInputStream.readObject();
            this = newSocialNetwork;
        }

}

然而，如您所见，我试图通过使 this = newSocialNetwork.这给了我预期的错误。我可以通过将当前 SocialNetwork class 的每个字段设置为 newSocialNetwork 来解决这个问题。但是，我不想这样做，因为我的 class 中有大量字段。而且会显得很乱。我希望您已经了解我正在尝试做的事情。

Answer 1

你不能那样做，但你可以声明一个静态方法。

 public static SocialNetwork readfromObject(File f) throws IOException, ClassNotFoundException{
            ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream(f));
            return (SocialNetwork) objectInputStream.readObject();

        }

Answer 2

由于您无法在 Java 中覆盖它，并且您只想让 class 的一个实例使用 Singelton Pattern:

public class SocialNetwork  implements Serializable{
    // lots of fields

    private static SocialNetwork myself = new SocialNetwork();

    private SocialNetwork(){ // private constructor
        //lots of inilization
    }

    public static SocialNetwork getInstance() { 
        return myself; 
    }

    public void writethisObject() throws IOException{...}

    public void readfromObject(File f) throws IOException, ClassNotFoundException{
        ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream(f));
        myself = (SocialNetwork) objectInputStream.readObject();
    }

}

Answer 3

我们可以使用单例模式来实现。类外部社交网络将使用 SocialNetwork.getInstance() 来初始化社交网络。这是代码

public class SocialNetwork  implements Serializable{

    // lots of fields   
    private static SocialNetwork myself = null;


    private SocialNetwork(){
    //lots of inilization
    } 


    public static SocialNetwork getInstance() { 

        if (myself == null){
            myself = new SocialNetwork();
        }
        return myself; 
    }


    public void writethisObject() throws IOException{
            ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream("Simulation.bin"));
            objectOutputStream.writeObject(this);
        }

        public void readfromObject(File f) throws IOException, ClassNotFoundException{
            ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream(f));
            SocialNetwork newSocialNetwork = (SocialNetwork) objectInputStream.readObject();
            myself = newSocialNetwork;
        }

}

有没有办法让currentclass指向刚读入Java的新对象Serializable？

Is there a way to make current class point to the new object that has just been read in Java Serializable?

java

file

object

serializable