【Head First Servlets and JSP】笔记 26： web 应用部署

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">

    <!-- Define servlets that are included in the web application -->

    <servlet>
        <servlet-name>jack</servlet-name>
        <servlet-class>sample.Jack</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet>
        <servlet-name>dog</servlet-name>
        <servlet-class>sample.Dog</servlet-class>
        <load-on-startup>2</load-on-startup>
    </servlet>
    
    <servlet-mapping>
        <servlet-name>jack</servlet-name>
        <url-pattern>/abc/*</url-pattern> <!-- 目录匹配 -->
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>dog</servlet-name>
        <url-pattern>/abc/3</url-pattern> <!-- 绝对匹配 -->
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>dog</servlet-name>
        <url-pattern>*.do</url-pattern> <!-- 扩展名匹配 -->
    </servlet-mapping> <!-- 容器优先查找绝对匹配，然后依次是目录匹配、扩展名匹配，如果有冲突总是取最特定的匹配，也就是路径更长长的 -->

    <!-- 启动容器就加载 servlet 不是默认行为！！！原因是!@$@$@$@%#$（自己想） -->

    <error-page>
        <!-- Throwable 是所有异常与错误的父类 -->
        <exception-type>java.lang.Throwable</exception-type>
        <location>/WEB-INF/jsp/exception/common-exception.jsp</location>
    </error-page>
    <error-page>
        <error-code>404</error-code>
        <location>/WEB-INF/jsp/exception/404-exception.jsp</location>
    </error-page>

    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>abc/3</welcome-file>
        <welcome-file>index.jsp</welcome-file> <!-- 与容器匹配规则不相同，文件名前不能放斜线！ -->
        <!-- 每个目录可能有各自的 index.html ！-->
        <!-- 容器先查 servlet 映射，没有才会找欢迎文件 -->
    </welcome-file-list>
    
</web-app>