java编辑序列化文件

Question

我用这段代码在一个序列化文件上写了10条记录/对象，现在我只想修改/编辑写在文件上的第6条记录/对象，保持其他记录/对象不变。请告诉我怎么做

import java.io.FileNotFoundException;  
import java.io.FileOutputStream;  
import java.io.IOException;  
import java.io.ObjectOutputStream;  
import java.io.Serializable;  
import java.util.Scanner;   

public class Write {     

    public static void main(String arg[]) throws FileNotFoundException, IOException {

        ObjectOutputStream to = new ObjectOutputStream(new FileOutputStream("file.cer"));
        Scanner out = new Scanner(System.in);
        String name;
        Double age;

        System.out.println("write NAME and AGE otherwise ctrl+z to teminate.");
        while(out.hasNext()) {
            name=out.nextLine();
            age=out.nextDouble();
            to.writeObject(new Data(name,age));
            System.out.println("write NAME and AGE otherwise ctrl+z to teminate.");
        }
        out.close();
        System.out.println("Ended");
    }
}

class Data implements Serializable {

    String name;
    Double age;

    public Data(String name, Double age) {
        this.name=name;
        this.age=age;
    }
}

Answer 1

I want to modify/edit only 6th record/object written on the file keeping other records/objects same. Please tell how I can do that?

实际上，你不能。序列化流包含块标记和数据计数，以及使其在一般情况下不可能实现的所有内容

Answer 2

我认为不可能编辑文件中的任何特定对象。你要做的是

1. 从文件中读取所有数据
2. 编辑所需的对象
3. 覆盖以前的数据