Here is the CacheHelper interface:
package com.sun.appserv.web.cache; import java.util.Map import javax.servlet.ServletContext; import javax.servlet.http.HttpServletRequest; /** CacheHelper interface is an user-extensible interface to customize: * a) the key generation b) whether to cache the response. */ public interface CacheHelper { // name of request attributes public static final String ATTR_CACHE_MAPPED_SERVLET_NAME = "com.sun.appserv.web.cachedServletName"; public static final String ATTR_CACHE_MAPPED_URL_PATTERN = "com.sun.appserv.web.cachedURLPattern"; public static final int TIMEOUT_VALUE_NOT_SET = -2; /** initialize the helper * @param context the web application context this helper belongs to * @exception Exception if a startup error occurs */ public void init(ServletContext context, Map props) throws Exception; /** getCacheKey: generate the key to be used to cache this request * @param request incoming <code>HttpServletRequest</code> object * @returns the generated key for this requested cacheable resource. */ public String getCacheKey(HttpServletRequest request); /** isCacheable: is the response to given request cacheable? * @param request incoming <code>HttpServletRequest</code> object * @returns <code>true</code> if the response could be cached. or * <code>false</code> if the results of this request must not be cached. */ public boolean isCacheable(HttpServletRequest request); /** isRefreshNeeded: is the response to given request to be refreshed? * @param request incoming <code>HttpServletRequest</code> object * @returns <code>true</code> if the response needs to be refreshed. * or return <code>false</code> if the results of this request * don't need to be refreshed. */ public boolean isRefreshNeeded(HttpServletRequest request); /** get timeout for the cached response. * @param request incoming <code>HttpServletRequest</code> object * @returns the timeout in seconds for the cached response; a return * value of -1 means the response never expires and a value of -2 indicates * helper cannot determine the timeout (container assigns default timeout) */ public int getTimeout(HttpServletRequest request); /** * Stop the helper from active use * @exception Exception if an error occurs */ public void destroy() throws Exception; }