自己在开发JavaEE的项目时，采用了基于Spring MVC + MyBatis +Sitemesh +AngularJS + semantic-ui的组合，使用maven作为项目管理、SVN作为代码版本控制工具。
前台通过ajax从后台获取数据，再在前台进行DOM渲染，于是，数据加载的时候，页面会有一定程度的"空白"现象。
为了解决这个问题，最好的办法的是把动态页面静态化，页面只进行一次渲染，但这种方式，略显麻烦，于是自己采取了片段化缓存和数据缓存的方式，加快
页面渲染和数据加载。
1.配置页面片段化缓存
为了统一页面风格，我使用Sitemesh来做页面布局。于是，页首的导航栏、菜单栏、页面底部的版权信息，可以直接缓存掉，比如下图(-1表示永久缓存)。
打开页面的速度确实提升很快。
数据缓存
对于页面、数据接口进行全局缓存，在web.xml配置如下:
<!– osCacheFilter –><filter><filter-name>osCacheFilter</filter-name><filter-class>com.opensymphony.oscache.web.filter.CacheFilter</filter-class><init-param><param-name>time</param-name><param-value>7200</param-value><!– 2h –></init-param><init-param><param-name>scope</param-name><param-value>application</param-value><!– default –></init-param></filter><filter-mapping><filter-name>osCacheFilter</filter-name><url-pattern>/</url-pattern><!– home page –></filter-mapping><filter-mapping><filter-name>osCacheFilter</filter-name><url-pattern>/group/*</url-pattern></filter-mapping><filter-mapping><filter-name>osCacheFilter</filter-name><url-pattern>/article/*</url-pattern></filter-mapping><filter-mapping><filter-name>osCacheFilter</filter-name><url-pattern>/case/*</url-pattern></filter-mapping><filter-mapping><filter-name>osCacheFilter</filter-name><url-pattern>/disease/*</url-pattern></filter-mapping><filter-mapping><filter-name>osCacheFilter</filter-name><url-pattern>/doctor/*</url-pattern></filter-mapping><filter-mapping><filter-name>osCacheFilter</filter-name><url-pattern>/drug/*</url-pattern></filter-mapping><filter-mapping><filter-name>osCacheFilter</filter-name><url-pattern>/hospital/*</url-pattern></filter-mapping><filter-mapping><filter-name>osCacheFilter</filter-name><url-pattern>/page/*</url-pattern></filter-mapping><filter-mapping><filter-name>osCacheFilter</filter-name><url-pattern>/u/*</url-pattern></filter-mapping>
2.源码
个人从github上得到相关源码，地址：https://github.com/cdemoustier/opensymphony-oscache-backup
web.xml这么配置参数，是如何被OSCache得到呢？
先看com.opensymphony.oscache.web.filter.CacheFilter类，它的init方法如下：
/** * Initialize the filter. This retrieves a {@link ServletCacheAdministrator} * instance and configures the filter based on any initialization * parameters. * <p> * The supported initialization parameters are: * <ul> * * <li><b>oscache-properties-file</b> – the properties file that contains * the OSCache configuration options to be used by the Cache that this * Filter should use.</li> * * @param filterConfig *The filter configuration */public void init(FilterConfig filterConfig) {// Get whatever settings we want…config = filterConfig;log.info("OSCache: Initializing CacheFilter with filter name "+ config.getFilterName());// setting the request filter to avoid reentrance with the same filterrequestFiltered = REQUEST_FILTERED + config.getFilterName();log.info("Request filter attribute is " + requestFiltered);// filter Properties fileProperties props = null;try {String propertiesfile = config.getInitParameter("oscache-properties-file");if (propertiesfile != null && propertiesfile.length() > 0) {props = Config.loadProperties(propertiesfile,"CacheFilter with filter name '"+ config.getFilterName() + "'");}} catch (Exception e) {log.info("OSCache: Init parameter 'oscache-properties-file' not set, using default.");}admin = ServletCacheAdministrator.getInstance(config.getServletContext(), props);// filter parameter timeString timeParam = config.getInitParameter("time");if (timeParam != null) {try {setTime(Integer.parseInt(timeParam));} catch (NumberFormatException nfe) {log.error("OSCache: Unexpected value for the init parameter 'time', defaulting to one hour. Message="+ nfe.getMessage());}}// filter parameter scopeString scopeParam = config.getInitParameter("scope");if (scopeParam != null) {if ("session".equalsIgnoreCase(scopeParam)) {setCacheScope(PageContext.SESSION_SCOPE);} else if ("application".equalsIgnoreCase(scopeParam)) {setCacheScope(PageContext.APPLICATION_SCOPE);} else {log.error("OSCache: Wrong value '"+ scopeParam+ "' for init parameter 'scope', defaulting to 'application'.");}}// filter parameter cronsetCron(config.getInitParameter("cron"));….// filter parameter scopeString disableCacheOnMethodsParam = config.getInitParameter("disableCacheOnMethods");if (StringUtil.hasLength(disableCacheOnMethodsParam)) {disableCacheOnMethods = StringUtil.split(disableCacheOnMethodsParam, ',');// log.error("OSCache: Wrong value '" + disableCacheOnMethodsParam +// "' for init parameter 'disableCacheOnMethods', defaulting to 'null'.");}}
通过FilterConfig filterConfig来获取参数值，完成初始化。
那Cache是如何对request进行过滤呢？
也站在未路让我牵挂的人。
