once again, why not Duration instead of long? -igor
On Sat, Sep 11, 2010 at 3:32 AM, <[email protected]> wrote: > Author: pete > Date: Sat Sep 11 10:32:04 2010 > New Revision: 996115 > > URL: http://svn.apache.org/viewvc?rev=996115&view=rev > Log: > helper method to utilize caching easier > > Modified: > > wicket/trunk/wicket/src/main/java/org/apache/wicket/protocol/http/RequestUtils.java > > Modified: > wicket/trunk/wicket/src/main/java/org/apache/wicket/protocol/http/RequestUtils.java > URL: > http://svn.apache.org/viewvc/wicket/trunk/wicket/src/main/java/org/apache/wicket/protocol/http/RequestUtils.java?rev=996115&r1=996114&r2=996115&view=diff > ============================================================================== > --- > wicket/trunk/wicket/src/main/java/org/apache/wicket/protocol/http/RequestUtils.java > (original) > +++ > wicket/trunk/wicket/src/main/java/org/apache/wicket/protocol/http/RequestUtils.java > Sat Sep 11 10:32:04 2010 > @@ -28,6 +28,7 @@ import org.apache.wicket.request.UrlDeco > import org.apache.wicket.request.cycle.RequestCycle; > import org.apache.wicket.request.http.WebResponse; > import org.apache.wicket.request.mapper.parameter.PageParameters; > +import org.apache.wicket.util.lang.Args; > import org.apache.wicket.util.string.Strings; > > /** > @@ -35,6 +36,8 @@ import org.apache.wicket.util.string.Str > */ > public final class RequestUtils > { > + public static final long MAX_CACHE_DURATION = 60 * 60 * 24 * 365; // > one year, maximum recommended cache duration > + > /** > * Decode the provided queryString as a series of key/ value pairs and > set them in the provided > * value map. > @@ -260,9 +263,76 @@ public final class RequestUtils > */ > public static void disableCaching(WebResponse response) > { > + Args.notNull(response, "response"); > response.setDateHeader("Date", System.currentTimeMillis()); > response.setDateHeader("Expires", 0); > response.setHeader("Pragma", "no-cache"); > response.setHeader("Cache-Control", "no-cache"); > } > + > + /** > + * enable caching for the given response > + * <p/> > + * The [duration] is the maximum time in seconds until the response > is invalidated from the cache. The > + * maximum duration should not exceed one year, based on > + * <a > href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html";>RFC-2616</a>. > + * <p/> > + * The [cachePublic] flag will let you control if the response may be > cached > + * by public caches or just by the client itself. This sets the http > response header > + * > + * <ul> > + * <li><code>[Cache-Control: public]</code> if <code>cachePublic = > true</code></li> > + * <li><code>[Cache-Control: private]</code> if <code>cachePublic = > false</code></li> > + * </ul> > + * <p/> > + * Details on <code>Cache-Control</code> header can be found > + * <a > href="http://palisade.plynt.com/issues/2008Jul/cache-control-attributes";>here</a> > + * or in <a > href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html";>RFC-2616</a>. > + * <p/> > + * Choose <code>cachePublic = false</code> wisely since setting > <code>Cache-Control: private</code> > + * may cause trouble with some versions of Firefox which will not > cache SSL content at all. More details > + * on this Firefox issue can be found <a > href="http://blog.pluron.com/2008/07/why-you-should.html";>here</a>. > + * <p/> > + * Never set <code>cachePublic=true</code> when the response is > confidential or client-specific. You > + * don't want to see your sensitive private data on some public proxy. > + * <p/> > + * Unless the response really is confidential / top-secret or > client-specific the general advice is > + * to always prefer <code>cachePublic=true</code> for best network > performance. > + * > + * @param response > + * response that should be cacheable > + * @param duration > + * duration in seconds that the response may be cached > + * @param cachePublic > + * If <code>true</code> all caches are allowed to cache > the response. > + * If <code>false</code> only the client may cache the > response (if at all). > + * > + * @see RequestUtils#MAX_CACHE_DURATION > + */ > + public static void enableCaching(WebResponse response, long duration, > boolean cachePublic) > + { > + Args.notNull(response, "response"); > + > + if(duration < 0) > + throw new IllegalArgumentException("duration must be > a positive value"); > + > + // Get current time > + long now = System.currentTimeMillis(); > + > + // Time of message generation > + response.setDateHeader("Date", now); > + > + // Time for cache expiry = now + duration > + response.setDateHeader("Expires", now + (duration * 1000L)); > + > + // Set caching scope > + String scope = cachePublic ? "public" : "private"; > + > + // Enable caching and set max age > + response.setHeader("Cache-Control", scope + ", max-age=" + > duration); > + > + // Let caches distinguish between compressed and uncompressed > + // versions of the resource so they can serve them properly > + response.setHeader("Vary", "Accept-Encoding"); > + } > } > > >
