线程“main”中的异常java.lang.ClassCastException

Question

import java.io.*;

class rak implements Serializable{

    int i;

}

public class Main {

    public static void main(String[] args) throws Exception {

        // write your code herer

        rak r = new rak();

        r.i = 9;

        File f = new File("da.txt");

        FileOutputStream f1 = new FileOutputStream(f);

        ObjectOutputStream oos = new ObjectOutputStream(f1);

        oos.writeObject("value of  i is" + r.i);

        FileInputStream f0 = new FileInputStream(f);

        ObjectInputStream f9 = new ObjectInputStream(f0);

        rak r1 = new rak();

        r1 = (rak) f9.readObject();

        System.out.println(r1.i);

    }

}

Answer 1

你序列化一个String：rak r = new rak();...oos.writeObject("value of  i is" + r.i);然后将反序列化结果转换为rak对象：r1 = (rak) f9.readObject();而ClassCastException: aString不是 a rak。如果要反rak序列化a ，请对其进行序列化，而不仅仅是其中一个字段，例如：oos.writeObject(r);