HttpServlet为什么实现Serializable? [英] Why does HttpServlet implement Serializable?

问题描述

在我对Servlet的理解中，该Servlet将由Container实例化，其init()方法将被调用一次，并且Servlet将像单例一样生活，直到JVM关闭.

In my understanding of Servlet, the Servlet will be instantiated by the Container, its init() method will be called once, and the servlet will live like a singleton until the JVM shuts down.

我不希望我的servlet被序列化，因为当应用服务器恢复或正常启动时，它将被重新构造.该servlet不应该包含特定于会话的成员，因此将其写入磁盘并重新实例化是没有意义的. 有实际用途吗?

I do not expect my servlet to be serialized, since it will be constructed new when the app server recovers or is starts up normally. The servlet should hold no session-specific members, so it does not make sense for it to be written to disk and re-instantiated. Is there a practical use for this?

我担心的是，我在其中放置了一些不可序列化的字段，然后我的应用程序会在生产环境中神秘地失败，在该生产环境中将进行不同类型的会话复制.

My concerns are, that I put some non-serializable fields within there and then my app will mysteriously fail in a production environment where a different sort of session replication will take place.

推荐答案

从技术上讲，我认为允许servlet容器以与EJB会话bean相似的方式将servlet对象钝化"到磁盘.因此，您正确的问题是您的应用是否会由于无法序列化的字段而失败.

Technically, I believe the servlet container is allowed to "passivate" the servlet object to disk, in a similar way that EJB session beans can be. So you're correct to ask the question if your app will fail due to non-serializable fields.

实际上，我从未听说过有容器可以这样做，所以实际上这只是早期J2EE糟糕时期的遗留物.我不用担心.

In practise, I've never heard of a container doing this, so it's really just legacy baggage from the bad old days of early J2EE. I wouldn't worry about it.

这篇关于HttpServlet为什么实现Serializable?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！