是不是对gzip压缩很亲切？ 对的，就是传说中可以压缩图片减少网络传输体积的玩意，现在你只要在web.xml中增加以下内容就可以轻松实现了:
<filter>
<filter-name>CompressionFilter</filter-name>
<filter-class>javawebparts.filter. CompressionFilter</filter-class>
<init-param>
<param-name>pathSpec</param-name>
<param-value>include</param-value>
</init-param>
<init-param>
<param-name>pathList</param-name>
<param-value>*/bigimage2.gif</ param-value>
</init-param>
<init-param>
<param-name>compressType</param-name>
<param-value>gzip_first</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CompressionFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<filter-name>CompressionFilter</filter-name>
<filter-class>javawebparts.filter. CompressionFilter</filter-class>
<init-param>
<param-name>pathSpec</param-name>
<param-value>include</param-value>
</init-param>
<init-param>
<param-name>pathList</param-name>
<param-value>*/bigimage2.gif</ param-value>
</init-param>
<init-param>
<param-name>compressType</param-name>
<param-value>gzip_first</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CompressionFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
上面的配置表示只对bigimage2.gif的文件进行压缩，其他不用,pathSpec的属性有两种include,exclude,意思已经很明确了，相反地意思,而pathList得内部实现也是用正则表达式实现的，支持*等用法.这些内部实现你觉得复杂的话就不用管它了，反正人家已经给你实现好了，你只要说"给我压缩'美女与野兽.JPG'"就可以了
