Filter配置大全

 在Java web开发中常会使用到功能强大的过滤器，他毕竟能给我们带来很大的方便，但是针对过滤的资源我们需要详细的了解他们在web.xml中的配置信息。这个根据几种常用的不同情况进行了总结： 

1。如果要映射过滤应用程序中所有资源： 

<filter> 
    <filter-name>loggerfilter</filter-name> 
    <filter-class>myfilter.LoggerFilter</filter-class> 
</filter> 
<filter-mapping> 
    <filter-name>loggerfilter</filter-name> 
    <url-pattern>/*</url-pattern> 
</filter-mapping> 

2.过滤指定的类型文件资源 

<filter> 
    <filter-name>loggerfilter</filter-name> 
    <filter-class>myfilter.LoggerFilter</filter-class> 
</filter> 
<filter-mapping> 
    <filter-name>loggerfilter</filter-name> 
    <url-pattern>*.html</url-pattern> 
</filter-mapping> 

其中<url-pattern>*.html</url-pattern>要过滤jsp那么就改*.html为*.jsp,但是注意没有“/”斜杠 

如果要同时过滤多种类型资源： 

<filter> 
    <filter-name>loggerfilter</filter-name> 
    <filter-class>myfilter.LoggerFilter</filter-class> 
</filter> 
<filter-mapping> 
    <filter-name>loggerfilter</filter-name> 
    <url-pattern>*.html</url-pattern> 
</filter-mapping> 

<filter-mapping> 
    <filter-name>loggerfilter</filter-name> 
    <url-pattern>*.jsp</url-pattern> 
</filter-mapping> 

3.过滤指定的目录 

<filter> 
    <filter-name>loggerfilter</filter-name> 
    <filter-class>myfilter.LoggerFilter</filter-class> 
</filter> 
<filter-mapping> 
    <filter-name>loggerfilter</filter-name> 
    <url-pattern>/folder_name/*</url-pattern> 
</filter-mapping> 

4.过滤指定的servlet 

<filter> 
    <filter-name>loggerfilter</filter-name> 
    <filter-class>myfilter.LoggerFilter</filter-class> 
</filter> 
<filter-mapping> 
    <filter-name>loggerfilter</filter-name> 
    <servlet-name>loggerservlet</servlet-name> 
</filter-mapping> 
<servlet> 
    <servlet-name>loggerservlet</servlet-name> 
    <servlet-class>myfilter.LoggerServlet</servlet-class> 
</servlet> 

5.过滤指定文件 

<filter> 
    <filter-name>loggerfilter</filter-name> 
    <filter-class>myfilter.LoggerFilter</filter-class> 
</filter> 
<filter-mapping> 
    <filter-name>loggerfilter</filter-name> 
    <url-pattern>/simplefilter.html</url-pattern> 
</filter-mapping> 

以上都要注意是否有斜杠“/”