Ⅰ、请求URL
Ⅱ、容器搜索DD，查找servlet-mapping
<?xml version="1.0" encoding="ISO-8859-1" ?> <web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4"> <servlet> <servlet-name>Ch3 Beer</servlet-name> <servlet-class>com.example.web.BeerSelect</servlet-class> </servlet> <servlet-mapping> <servlet-name>Ch3 Beer</servlet-name> <url-pattern>/SelectBeer.do</url-pattern> </servlet-mapping> </web-app>
Ⅲ、找到url-pattrern所对应的DD内部的servlet-name
<servlet-mapping> <servlet-name>Ch3 Beer</servlet-name> <url-pattern>/SelectBeer.do</url-pattern> </servlet-mapping>
Ⅳ、利用servlet-name查找对应的servlet
<servlet> <servlet-name>Ch3 Beer</servlet-name> <servlet-class>com.example.web.BeerSelect</servlet-class> </servlet> <servlet-mapping> <servlet-name>Ch3 Beer</servlet-name> <url-pattern>/SelectBeer.do</url-pattern> </servlet-mapping>
Ⅴ、容器加载类，并初始化servlet（如果还没有初始化的话）
<servlet> <servlet-name>Ch3 Beer</servlet-name> <servlet-class>com.example.web.BeerSelect</servlet-class> </servlet>
Ⅵ、容器开启一个新线程处理并传递request（传递给servlet的service()方法）
Ⅶ、容器把响应发回给客户
原文：http://www.cnblogs.com/xkxf/p/6848362.html