在不同的 classes 中读写（序列化）静态嵌套 class 对象

Question

我想序列化一个包含静态嵌套 CustomClass 对象作为其值的 Map 对象。

public class A{

    static Map<String, CustomClass> map = new HashMap<>();

    public static void main(String[] args) {
        map.put("ABC", new CustomClass(1, 2L, "Hello"));
        writeToFile();
    }

    private static void writeToFile() throws IOException, ClassNotFoundException {
        ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("file.ser"));
        out.writeObject(map);
    }

    private static class CustomClass implements Serializable {
        int x;
        long y;
        String z;
        private static final long serialVersionUID = 87923834787L;
        private CustomClass (int x, long y, String z) {
         .....
        }
    }

}


public class B {

    static Map<String, CustomClass> map = new HashMap<>();

    public static void main( String[] args) {
        readFromFile();
    }

    private static void readFromFile() throws IOException, ClassNotFoundException {
        ObjectInputStream out = new ObjectInputStream(new FileInputStream("file.ser"));
        map = out.readObject(); // ClassNotFoundException occured
    }

    private static class CustomClass implements Serializable {
        int x;
        long y;
        String z;
        private static final long serialVersionUID = 87923834787L;
        private CustomClass (int x, long y, String z) {
         .....
        }

        //some utility methods
        ....
    }

}

当我尝试读取序列化的 Map 对象时，它抛出 ClassNotFoundException。是不是因为在不同class下定义的同一个嵌套class会有不同的名称或版本？

该问题的可能解决方案是什么。谢谢

Answer 1

嵌套 class 全名包括封闭的 class 姓名。 A 写入 A$CustomClass 并且 B 有 B$CustomClass

Answer 2

Is it because the same inner class defined under different class will have different name or version?

因为'same inner class defined under different class'是个自相矛盾的词。不一样。这是不同的 class.

注意 static inner is also a contradiction in terms.

Answer 3

在你的 class B 中，我已经替换为下面的行，它对我来说工作正常。

 map = (Map<String, CustomClass>) out.readObject();//Line no 19

此外，我无法在 ObjectInputStream 中找到 readObject(Object) 以 Object 作为参数的方法。

在不同的 classes 中读写（序列化）静态嵌套 class 对象

Reading and Writing (Serializing) static nested class object in different classes

java

serialization

exception

core