java - 我不断收到 java.io.NotSerializableException : java. io.ObjectOutputStream

Question

这是我一直在尝试的代码

import java.util.Scanner;
import java.io.*;

abstract class Account implements Serializable {
    protected String accountHolderName;
    protected long balance;

    protected ObjectOutputStream accData;

    Scanner input = new Scanner(System.in);
}

class Savings extends Account implements Serializable {

    Savings() throws IOException {
        System.out.print("enter your name: ");
        accountHolderName = input.nextLine();
        System.out.print("\n");
        System.out.print("enter your balance: ");
        balance = input.nextLong();
        accData = new ObjectOutputStream(new FileOutputStream(accountHolderName + ".bin"));
        accData.writeObject(this);
        accData.close();
    }
}

class Banking implements Serializable {
    public static void main(String args[]) throws IOException {
        Scanner input = new Scanner(System.in);
        Savings savobj = new Savings();
    }
}

这是我得到的异常

Exception in thread "main" java.io.NotSerializableException: java.io.ObjectOutputStream at java.io.ObjectOutputStream.writeObject0(Unknown Source) at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source) at java.io.ObjectOutputStream.writeSerialData(Unknown Source) at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source) at java.io.ObjectOutputStream.writeObject0(Unknown Source) at java.io.ObjectOutputStream.writeObject(Unknown Source) at Savings.(Banking.java:22) at Banking.main(Banking.java:30)

我也尝试使用 main() 中的 savobj.accData.writeObj(savobj)，但我仍然遇到相同的异常。我该怎么办？

Answer 1

只有实现Serializable 接口(interface)的原语和类才能被序列化。 ObjectOutputStream 没有实现这个接口(interface)。

快速解决方案:在尽可能窄的范围内使用 ObjectOutputStream，在使用它的方法中声明它，而不是作为类中的字段。对其他实用程序类执行类似操作，例如 Scanner。

abstract class Account implements Serializable {
    protected String accountHolderName;
    protected long balance;

    //protected ObjectOutputStream accData;

    //Scanner input = new Scanner(System.in);
}

class Savings extends Account implements Serializable {

    Savings() throws IOException {
        Scanner input = new Scanner(System.in);
        System.out.print("enter your name: ");
        accountHolderName = input.nextLine();
        System.out.print("\n");
        System.out.print("enter your balance: ");
        balance = input.nextLong();
        ObjectOutputStream accData = new ObjectOutputStream(new FileOutputStream(accountHolderName + ".bin"));
        accData.writeObject(this);
        accData.close();
    }
}

另一种解决方案可能只是将这些字段标记为transient，这样它们就不会被序列化/反序列化:

abstract class Account implements Serializable {
    protected String accountHolderName;
    protected long balance;

    protected transient ObjectOutputStream accData;

     transient Scanner input = new Scanner(System.in);
}