java - 为什么 Java Bean 必须是可序列化的？

Question

Java Bean 是否有必要实现Serializable 接口(interface)？

Answer 1

这是 Javabeans specification 中描述的“典型”功能之一.

这是 2.1 什么是 bean？ 章节的摘录

Individual Java Beans will vary in the functionality they support, but the typical unifying features that distinguish a Java Bean are:

• Support for “introspection” so that a builder tool can analyze how a bean works
• Support for “customization” so that when using an application builder a user can customize the appearance and behaviour of a bean.
• Support for “events” as a simple communication metaphor than can be used to connect up beans.
• Support for “properties”, both for customization and for programmatic use.
• Support for persistence, so that a bean can be customized in an application builder and then have its customized state saved away and reloaded later.

下面是 5.5 持久性总结一章的摘录:

All beans must support either Serialization or Externalization.

在实践中，它的运行并不是明确必需的。它通常也可以在不实现 Serializable 的情况下正常工作.然而，每当您想将它们“纯文本”存储在硬盘上或通过网络发送“纯文本”时，它就很有用。例如，当它是一个 session 范围的 bean，它将被存储在 HTTP session 中，并且服务器被配置为在关闭/重启期间保持和恢复 HTTP session 。无论如何，每当你面对 NotSerializableException在消息中使用 bean 的完全限定类名，那么它就足以让它实现 Serializable。