java - 初始化 int 数组中的值后，对该数组的更新将不会出现在 Serial 中

Question

这个问题已经有答案了:

Sending the same but modifed object over ObjectOutputStream (2 个回答)

已关闭 5 年前。

我一直在研究序列化对象，以便我可以轻松快速地通过网络发送对象。但这有一个大问题。在初始化数组中的值后，该数组的序列化对象将始终保持为初始化的数字。我什至不确定是否是这种情况，因为我很确定整数的默认值为 0。那么它不会保持为 0 而不是我将其更改为的值吗？

public static void main(String[] args) throws FileNotFoundException, IOException, ClassNotFoundException {
    FileOutputStream ostr = new FileOutputStream(new File("ObjectFile.yeh"));
    FileInputStream istr = new FileInputStream(new File("ObjectFile.yeh"));
    ObjectOutputStream out= new ObjectOutputStream(ostr);
    int[] hi = new int[5];
    hi[0]=3;
    out.writeUTF("This is an Array");
    out.writeObject(hi);
    hi[0]=5;
    out.writeObject(hi);
    out.writeUTF("Array Over");
    out.close();
    ObjectInputStream in = new ObjectInputStream(istr);
    System.out.println(in.readUTF());
    int[] h = (int[]) in.readObject();
    System.out.println(h[0]);
    int[] j = (int[]) in.readObject();
    System.out.println(j[0]);
    System.out.println(in.readUTF());
    in.close();
}

当我运行以下代码时，它会打印

This is an Array
3
3
Array Over

我该如何解决这个问题？

更新:

经过进一步的实验，我发现对象被序列化一次后，它的序列号似乎没有改变。如此处所示，我编辑了字符串数组，它的内容在通过对象流发送后没有改变

    public static void main(String[] args) throws FileNotFoundException, IOException, ClassNotFoundException {
    FileOutputStream ostr = new FileOutputStream(new File("ObjectFile.yeh"));
    FileInputStream istr = new FileInputStream(new File("ObjectFile.yeh"));
    ObjectOutputStream out= new ObjectOutputStream(ostr);
    String[] hi = new String[5];
    hi[0]="Hi";
    out.writeUTF("This is an Array");
    out.writeObject(hi);
    hi[0]="Hello";
    hi[1]="Hoopla";
    out.writeObject(hi);
    out.writeUTF("Array Over");
    out.close();
    ObjectInputStream in = new ObjectInputStream(istr);
    System.out.println(in.readUTF());
    String[] h = (String[]) in.readObject();
    System.out.println(h[0]+" "+h[1]);
    String[] j = (String[]) in.readObject();
    System.out.println(j[0]+" "+j[1]);
    System.out.println(in.readUTF());
    in.close();
}

这会打印

This is an Array
Hi null
Hi null
Array Over

Answer 1

在更改输出流之前重置它。

public static void main(String[] args) throws FileNotFoundException, IOException, ClassNotFoundException {
    FileOutputStream ostr = new FileOutputStream(new File("ObjectFile.yeh"));
    FileInputStream istr = new FileInputStream(new File("ObjectFile.yeh"));
    ObjectOutputStream out= new ObjectOutputStream(ostr);
    int[] hi = new int[5];
    hi[0]=3;
    out.writeUTF("This is an Array");
    out.writeObject(hi);
    out.reset(); // Add this line
    hi[0]=5;
    out.writeObject(hi);
    out.writeUTF("Array Over");
    out.close();
    ObjectInputStream in = new ObjectInputStream(istr);
    System.out.println(in.readUTF());
    int[] h = (int[]) in.readObject();
    System.out.println(h[0]);
    int[] j = (int[]) in.readObject();
    System.out.println(j[0]);
    System.out.println(in.readUTF());
    in.close();
}