Java使用继承进行序列化吗？

Question

这是Goals.java

public abstract class Goals {
private String score;

public Goals(String str) {
    this.score = str;
}

String getGoals() {
    return this.score;
}

   void doSomething(score) {
    }
    }

这是Game.java

public class Game implements Serializable {
    public String name;
    public int game_num;
    public int opp;
    public int player;
    public Goals goal;

    public Game(int i, int i2, int i3) {
        this.player = i;
        this.game_num = i2;
        this.opp = i3;
    }

    public Game(String str, Goals goal) {
        this.name = str;
        this.goal = goal;
    }

}

我们是否可以创建一个序列化对象，使其在反序列化并强制转换为Game后，在Goals.java中设置score？此外，如果序列化数据来自不受信任的来源，您是否可以操作/覆盖doSomething方法？

Answer 1

在你试图操纵你的对象的方式中，我认为你可以做到Goals实现Serializable，而游戏实现Goals：

public abstract class Goals implements Serializable{
private String score;

public Goals(String str) {
    this.score = str;
}

String getGoals() {
    return this.score;
}

   void doSomething(score) {
    }
    }

对于游戏

public class Game extends Goals {
    public String name;
    public int game_num;
    public int opp;
    public int player;

    public Game(int i, int i2, int i3) {
        this.player = i;
        this.game_num = i2;
        this.opp = i3;
    }

    public Game(String str) {
        //create constructor also including the properties of Goals
        Super()...
    }

}

Answer 2

正如注释中提到的，使用Serializable实现Goals及其实现，并在这两个类中实现默认构造函数。

工作代码片段：

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

abstract class Goals implements Serializable{
private String score;


public Goals() {
    this(null);
}

public Goals(String str) {
    this.score = str;
}

String getGoals() {
    return this.score;
}

   void doSomething(int score) {
    }
    }

class Game implements Serializable {
    public String name;
    public int game_num;
    public int opp;
    public int player;
    public Goals goal;

    public Game(int i, int i2, int i3) {
        this.player = i;
        this.game_num = i2;
        this.opp = i3;
    }

    public Game(String str, Goals goal) {
        this.name = str;
        this.goal = goal;
    }

}

class GoalImpl extends Goals implements Serializable{
    public GoalImpl() {
        }
    public GoalImpl(String str) {
        super(str);
    }

}

public class Main{
    public static void main(String...s) {
        Goals goal = new GoalImpl("20");
        Game game = new Game("name",goal);

        try
        {   
            //Saving of object in a file
            FileOutputStream file = new FileOutputStream("gamefile.ser");
            ObjectOutputStream out = new ObjectOutputStream(file);


            // Method for serialization of object
            out.writeObject(game);

            out.close();
            file.close();

            System.out.println("Object has been serialized");

        }

        catch(IOException ex)
        {
            ex.printStackTrace();
            System.out.println("IOException is caught");
        }


        Game object1 = null;

        // Deserialization
        try
        {   
            // Reading the object from a file
            FileInputStream file = new FileInputStream("gamefile.ser");
            ObjectInputStream in = new ObjectInputStream(file);

            // Method for deserialization of object
            object1 = (Game)in.readObject();

            in.close();
            file.close();

            System.out.println("Object has been deserialized ");
            System.out.println("score = " + object1.goal.getGoals());
        }

        catch(IOException ex)
        {
            ex.printStackTrace();
            System.out.println("IOException is caught");
        }

        catch(ClassNotFoundException ex)
        {
            System.out.println("ClassNotFoundException is caught");
        }


    }
}

输出：

Object has been serialized
Object has been deserialized 
score = 20

PS：

1. 建议将比分设置为整数，否则您将无法执行基本操作，如使用内置运算符(+，-)增加比分或减少比分。
2. 总是放置正确的getter setter名称，如getScore()和setScore int这种情况下。
3. 确实尝试使构造函数同步，例如，在调用具有玩家id的游戏构造函数时，游戏编号和目标将永远不会被初始化。最好使用默认值或其他更好的方法初始化它们，使另一个构造函数接受所有参数，然后从单个构造函数中调用主构造函数，并为那些未被调用方法传递的构造函数传递默认值。