压缩传输与客户端缓存(EHRGZIPFilter和CacheHeaderFilter)

在进行B/S前端开发时，页面代码要注意分离。这么做才是一种优良的编码行为。
    1、js、css、html结构分离，可以使得页面更加整洁
    2、js、css与html的分离可以使代码更大程度的重用
    3、分离的结构便于脚本的平稳退化（迫使写出更好的额浏览器兼容js）
    4、分离的结构可以对各种元素进行处理。如：
         1）可以对js、jsp、图片等等进行压缩
         2）可以对上述的js文件、css文件等进行压缩，通过压缩后传送到客户端，节约了网络资源
    通过分离后，可以采用压缩技术与客户端缓存技术来优化项目。
    在我使用的项目中，就采用了tk-filters来实现这一目的
    1、下载tk-filters-1.0.1.zip
    2、解压后将tk-filters.jar放到类路径
    3、在解压后的conf目录下打开tk-filters.properties文件，里面涉及到了三个大项的配置
    4、修改tk-filters.properties文件的压缩与缓存，使得启动这些功能

          ①、GZIPFilter.Enabled=true

          ②、GZIPFilter.LogStats=true         

          ③、CacheFilter.Enabled=true
    5、conf目录下面还有一个默认的web.xml文件的配置示例，上面都讲述了配置注意事项
    6、在按照默认的示例配置web.xml时，还要根据实际情况进行配置，示例如下：

<filter>
    	<filter-name>GZIPFilter</filter-name>
    	<display-name>GZIPFilter</display-name>
    	<description>Transparently compresses server output using Gzip encoding, when possible</description>
    	<filter-class>com.bsoft.hzehr.biz.filter.GZIPFilter</filter-class>
  	</filter>  
  	<filter>
    	<filter-name>CacheFilter</filter-name>
    	<display-name>CacheFilter</display-name>
    	<description>Sends Expires HTTP headers to reduce unnecessary network traffic</description>
    	<filter-class>com.tacitknowledge.filters.cache.CacheHeaderFilter</filter-class>
  	</filter>
  
	<filter-mapping>
		<filter-name>GZIPFilter</filter-name>
		<url-pattern>*.js</url-pattern>
	</filter-mapping>
  	<filter-mapping>
    	<filter-name>GZIPFilter</filter-name>
    	<url-pattern>*.css</url-pattern>
  	</filter-mapping>
	<filter-mapping>
    	<filter-name>GZIPFilter</filter-name>
    	<url-pattern>*.jsonRequest</url-pattern>
  	</filter-mapping>
  	<filter-mapping>
    	<filter-name>GZIPFilter</filter-name>
    	<url-pattern>*.jshtml</url-pattern>
  	</filter-mapping>
  	<filter-mapping>
    	<filter-name>GZIPFilter</filter-name>
    	<url-pattern>*.dic</url-pattern>
  	</filter-mapping>
  	<filter-mapping>
    	<filter-name>GZIPFilter</filter-name>
    	<url-pattern>*.chart</url-pattern>
  	</filter-mapping>
  	<filter-mapping>
    	<filter-name>GZIPFilter</filter-name>
    	<url-pattern>*.ichart</url-pattern>
  	</filter-mapping>
  	<filter-mapping>
    	<filter-name>GZIPFilter</filter-name>
    	<url-pattern>*.graphic</url-pattern>
  	</filter-mapping>
  	<filter-mapping>
    	<filter-name>GZIPFilter</filter-name>
    	<url-pattern>/services/*</url-pattern>
  	</filter-mapping>
  	<filter-mapping>
    	<filter-name>GZIPFilter</filter-name>
    	<url-pattern>/print</url-pattern>
  	</filter-mapping>
  	<filter-mapping>
    	<filter-name>GZIPFilter</filter-name>
    	<url-pattern>/listprint</url-pattern>
  	</filter-mapping>
  	<filter-mapping>
    	<filter-name>GZIPFilter</filter-name>
    	<url-pattern>*.etReport</url-pattern>
  	</filter-mapping>
	<filter-mapping>
		<filter-name>GZIPFilter</filter-name>
		<url-pattern>*.swf</url-pattern>
	</filter-mapping>	
	<filter-mapping>
		<filter-name>CacheFilter</filter-name>
		<url-pattern>*.js</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>CacheFilter</filter-name>
		<url-pattern>*.css</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>CacheFilter</filter-name>
		<url-pattern>*.gif</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>CacheFilter</filter-name>
		<url-pattern>*.jpg</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>CacheFilter</filter-name>
		<url-pattern>*.png</url-pattern>
	</filter-mapping>

 

参考资料：http://imti-qq.iteye.com/blog/1067202