Java 序列化 : Must E be serializable in ArrayList?

Question

我有以下类包含下面指定的字段。我的问题是，Admin、Worker 和我所有其他自定义类是否必须实现 Serializable 才能使 MyClass 实现可序列化？

public class MyClass implements java.io.Serializable {
  private static final long serialVersionUID = 1L;
  ArrayList<Admin> admins;
  ArrayList<Worker> workers;
  ArrayList<Manager> managers;
  ArrayList<Secretary> secretaries;
  ArrayList<Category> categories;
  HashMap<Issue, HashMap<Category,Manager>> ManagedIssues;
  private static MyClass instance;
      ...
}

Answer 1

My question is, must Admin, Worker and all my other self-defined classes implement Serializable for MyClass to be Serializable?

是的。他们必须是。

ArrayList 默认已经实现了Serializable接口(interface)。但是您需要为您使用的类型实现 Serializable 接口(interface)。

Serializability of a class is enabled by the class implementing the java.io.Serializable interface. Classes that do not implement this interface will not have any of their state serialized or deserialized. All subtypes of a serializable class are themselves serializable.