tomcat 7 源码分析-14 tomcat的container设计
tomcat 7 源码分析-14 tomcat的container设计
??????? 实现
container←-----containerBase
??? ↑???????????? ? ? ? ? ? ?? ↑
??? |继承??????????????????? |继承
??? |????????????????????????? |
??? |???????? 实现?????????? |
Engine←-----—-- StandardEngine
context?????????????? Standardcontext
host??????????????????? Standardhost
wrapper????????????? Standardwrapper
?
四种container分别是Engine,context,host和wrapper。
containerBase是对container相同部分的实现，四个interface又继承了container，增加了不同的部分。
如此StandardEngine，Standardcontext，Standardhost和Standardwrapper继承了相同的部分，同时实现了差异性的部分。
?
Engine:An Engine is a Container that represents the entire Catalina servlet engine.
?
Host:A Host is a Container that represents a virtual host in the Catalina servlet engine.
?
Context:A Context is a Container that represents a servlet context, and therefore an individual web application, in the Catalina servlet engine.
?
Wrapper: A Wrapper is a Container that represents an individual servlet definition from the deployment descriptor of the web application.
?
补充：写了一个简单的servlet，然后跟踪下发现如下
Engine=StandardEngine[Catalina]
host=StandardEngine[Catalina].StandardHost[localhost]
context=StandardEngine[Catalina].StandardHost[localhost].StandardContext[/WelcomeServlet]
wrapper=StandardEngine[Catalina].StandardHost[localhost].StandardContext[/WelcomeServlet].StandardWrapper[com.hotnosh.ServletTest.FirstServlet]
?
可以看出：
host实际是虚拟主机
context是webapplication，发布的web应用的根目录名
wrapper是具体处理servlet的
如此我在浏览器上输入http://localhost:8080/WelcomeServlet/FisrtServlet
?
?
GET /WelcomeServlet/FisrtServlet HTTP/1.1
Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/x-ms-application, application/x-ms-xbap, application/vnd.ms-xpsdocument, application/xaml+xml, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*
ThreadID: 4936
Accept-Language: zh-cn
UA-CPU: x86
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; SE 2.X; .NET CLR 2.0.50727; .NET CLR 1.1.4322; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; SE 2.X)
Host: localhost:8080
Connection: Keep-Alive
?
?
向tomcat发出http的request，tomcat解析请求后，一步步直到具体的servlet处理函数。
调用栈：
Http11Processor.process(SocketWrapper<Socket> socketWrapper)
adapter.service(request, response);
connector.getService().getContainer().getPipeline().getFirst().invoke(request, response);
//调用StandardEngine的StandardEngineValve.invoke
host.getPipeline().getFirst().invoke(request, response);
//调用StandardHost的StandardHostValve.invoke
context.getPipeline().getFirst().invoke(request, response);
//调用Standardcontext的StandardcontextValve.invoke
wrapper.getPipeline().getFirst().invoke(request, response);
//调用StandardWrapper的StandardWrapperValve.invoke
