spring mvc 的設計模式

1. 使用spring，在web.xml中配置一個DispatcherServlet。

   <!--配置 spring 的DispatcherServlet-->
<servlet>
        <servlet-name>SpringMVC</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <!--給出框架配置文件所在的路徑-->
            <param-value>classpath:conf/freemarker-servlet.xml</param-value>
        </init-param>
</servlet>


<!--freemarker-servlet在conf/freemarker-servlet.xml文件中的參數配置如下-->
<!-- freemark --> 
    <bean id="freemarkerConfig"
        class="org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer">
        <property name="templateLoaderPath" value="/WEB-INF/ftl/" />
        <property name="defaultEncoding" value="UTF-8" />
    </bean>

    <bean
        class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver">
        <property name="cache" value="true" />
        <property name="prefix" value="" />
        <property name="suffix" value=".ftl" />
        <property name="exposeSpringMacroHelpers" value="true" />
        <property name="exposeRequestAttributes" value="true" />
        <property name="exposeSessionAttributes" value="true" />
        <property name="requestContextAttribute" value="request" />
        <property name="contentType" value="text/html; charset=utf-8" />
    </bean>


<!--web.xml中的攔截會直接跳轉到對應的方法， 我們並不關心-->
<servlet>
        <servlet-name>authenticationServlet</servlet-name>
    <servlet-class>
        com.suning.ids.client.AuthenticationServlet
    </servlet-class>
    <load-on-startup>3</load-on-startup>
    </servlet>
    <servlet-mapping>
        <!--所有連接中包含/auth的url-->
        <!--都跳轉到com.suning.ids.client.AuthenticationServlet-->
        <servlet-name>authenticationServlet</servlet-name>
        <url-pattern>/auth</url-pattern>
    </servlet-mapping>
<!--只關心controller中request的方法-->

2.