如果我们使用spring mvc来做web访问请求的控制转发,那么默认所有访问都将被DispatcherServlet独裁统治。比如我现在想访问的欢迎页index.html根本无需任何业务逻辑处理,仅仅就展示一句话而已,但spring mvc还是会把访问index.html这件事交给DispatcherServlet处理,而DispatcherServlet会从HandlerMapping去找对应Controller注解,如果找不到就报错了:
spring mvc提供的解决方案是在配置文件中加入mvc:resources来专门标识静态资源,比如我的web.xml是这样的:
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<display-name>Memcache View Application</display-name>
<servlet>
<servlet-name>service-dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>service-dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-core.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
</web-app>
那么我的spring-mvc.xml就要是这样的:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd ">
<context:component-scan base-package="com.wulinfeng.memcache.view" />
<mvc:annotation-driven />
<mvc:resources location="/" mapping="/**/*.js"/>
<mvc:resources location="/" mapping="/**/*.css"/>
<mvc:resources location="/" mapping="/**/*.png"/>
<mvc:resources location="/" mapping="/*.html"/>
</beans>
这时就可以顺利访问index.html这个欢迎页了。其他js、css或png图片的静态资源也可以直接访问。如果我还要做拦截,比如登陆功能,又不想拦截到静态资源,怎么办呢?最简单的就是配置拦截时过滤静态资源:
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/**" />
<mvc:exclude-mapping path="/**/*.css" />
<mvc:exclude-mapping path="/**/*.js" />
<mvc:exclude-mapping path="/**/*.png" />
<mvc:exclude-mapping path="*.html" />
<mvc:exclude-mapping path="/login**" />
<mvc:exclude-mapping path="/register**" />
<mvc:exclude-mapping path="/getVerifyCode**" />
<mvc:exclude-mapping path="/getMethod/**" />
<bean class="com.wulinfeng.test.testpilling.util.InterceptorUtil" />
</mvc:interceptor>
</mvc:interceptors>