</servlet-class> <init-param>
<param-name>debug</param-name> <param-value>0</param-value> </init-param> <init-param>
<param-name>listings</param-name>
<param-value>true</param-value> </init-param>
<load-on-startup>1</load-on-startup> </servlet>
<!-- InvokerServlet
处理一个WEB APP中的匿名servlet
当一个servlet被编写并编译放入/WEB-INF/classes/中,却没有在/WEB-INF/web.xml中定义的时候 该servlet被调用,把匿名servlet映射成/servlet/ClassName的形式
URL PATTERN MAPPING : /servlet/* --> <servlet>
<servlet-name>invoker</servlet-name> <servlet-class>
org.apache.catalina.servlets.InvokerServlet </servlet-class> <init-param>
<param-name>debug</param-name> <param-value>0</param-value> </init-param>
<load-on-startup>2</load-on-startup> </servlet>
<!-- JspServlet
当请求的是一个JSP页面的时候(*.jsp)该servlet被调用
它是一个JSP编译器,将请求的JSP页面编译成为servlet再执行
URL PATTERN MAPPING : *.jsp --> <servlet>
<servlet-name>jsp</servlet-name>
<servlet-class>org.apache.jasper.servlet.JspServlet</ser
vlet-class>
<init-param>
<param-name>logVerbosityLevel</param-name>
<param-value>WARNING</param-value> </init-param>
<load-on-startup>3</load-on-startup> </servlet>
<!-- +---------------------------+ --> <!-- | servlet映射定义部分 | --> <!-- +---------------------------+ -->
<servlet-mapping>
<servlet-name>default</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <servlet-mapping>
<servlet-name>invoker</servlet-name> <url-pattern>/servlet/*</url-pattern> </servlet-mapping>
<servlet-mapping>
<servlet-name>jsp</servlet-name> <url-pattern>*.jsp</url-pattern> </servlet-mapping>
<!-- +------------------------+ --> <!-- | 其它部分,略去先 | --> <!-- +------------------------+ --> ... ... ... ... </web-app>
<!----------------------------------------------------------------------------------------------->
5 - Tomcat Server处理一个http请求的过程 假设来自客户的请求为:
http://localhost:8080/wsota/wsota_index.jsp
1) 请求被发送到本机端口8080,被在那里侦听的Coyote HTTP/1.1 Connector获得
2) Connector把该请求交给它所在的Service的Engine来处理,并等待来自Engine的回应
3) Engine获得请求localhost/wsota/wsota_index.jsp,匹配它所
拥有的所有虚拟主机Host
4) Engine匹配到名为localhost的Host(即使匹配不到也把请求交给该Host处理,因为该Host被定义为该Engine的默认主机)
5) localhost Host获得请求/wsota/wsota_index.jsp,匹配它所拥有的所有Context
6) Host匹配到路径为/wsota的Context(如果匹配不到就把该请求交给路径名为\的Context去处理)
7) path=\的Context获得请求/wsota_index.jsp,在它的mapping table中寻找对应的servlet
8) Context匹配到URL PATTERN为*.jsp的servlet,对应于JspServlet类
9) 构造HttpServletRequest对象和HttpServletResponse对象,作为参数调用JspServlet的doGet或doPost方法
10)Context把执行完了之后的HttpServletResponse对象返回给Host
11)Host把HttpServletResponse对象返回给Engine 12)Engine把HttpServletResponse对象返回给Connector 13)Connector把HttpServletResponse对象返回给客户browser