Question

I just wonder why does only one copy of a servlet get created. And if a brower requests a servlet for the first time. How does servlet deal with that. I know java will compile code before running it. How about servlet? Last, How is information stored in a session object?
I am new to java servlet, please help me.
Thanks!

Answer 1

• one servlet instance is created, because no more are needed. Each request is passed through the service(..) method in a separate thread
• servlets are already compiled when starting the server – they are .class files
• there is a <load-on-startup> configuration that lets you specify when should the container instantiate the servlet
• session is identified by a session cookie, which is sent with each request. When a client sends the session id, it is looked up in a table and the appropriate Session object is returned.