Hello Fabian,
thanks again for your report that helps to fix an issue introduced a
long time ago (november 2007)...
As you may know, the directory relies on a client connector (generally
defined on the Component). Such client connector supports a "timeToLive"
parameter which helps to calculate the expiration date. When set to 0,
there is no expiration date (here was the bug), otherwise it represents
the life time (in seconds) of the representation.
Here is the way to set this parameter:
Client c = new Client(Protocol.FILE);
component.getClients().add(c);
c.getContext().getParameters().add("timeToLive", "0");
Having said that, this parameters applies for all directories attached
in the set of applications of your component. If you want to customize
for only one directory, you can also use a filter (placed just before
your directory) that sets the expiration date at your own convenience in
the "afterHandle" method.
Regarding the second part of your question, you should override the
"get(Variant)" method... since there is by default negotiation of
content, that is to say a variant is chosen among the available ones
according to the preferences of the clients.
Best regards,
Thierry Boileau
> Hello there,
>
> part of my application uses static (never-expiring) resources like
> images, CSS stylesheets, etc. I'm currently serving those resources
> using the Directory class, like this:
>
> Directory dir = new Directory(getContext(), "clap://system/res");
> router.attach("/res", dir);
>
> However, this sets the Expires HTTP header to the current date,
> essentialy making the representations of those resources
> non-cacheable, so the client (web browser) has to request them over
> and over again and they trip the network wire over and over again.
> This is far from optimum, even for small-sized resource
> representations.
>
> So, after reading a bit some messages on this ML, I've decided to
> extend both Directory and DirectoryServerResource like this:
>
> public class ExpirableDirectoryResource extends Directory {
>
> public ExpirableDirectoryResource(Context context, Reference
> rootLocalReference) {
> super(context, rootLocalReference);
> setTargetClass(FarExpiringDirectoryResource.class);
> }
>
> public ExpirableDirectoryResource(Context context, String rootUri) {
> this(context, new Reference(rootUri));
> }
>
> }
>
> public class FarExpiringDirectoryResource extends DirectoryServerResource {
> Calendar expiresOn;
>
> public FarExpiringDirectoryResource() {
> super();
> expiresOn = Calendar.getInstance();
> expiresOn.add(Calendar.YEAR, 1); // By default, expire 1 yr from now
> getLogger().info(String.format("+++DBG: Expiration date set to
> %s", expiresOn.getTime()));
> }
>
> @Override
> public Representation get() throws ResourceException {
> getLogger().info("+++DBG: GET on FarExpiringDirectoryResource...");
> Representation rep = super.get();
> getLogger().info(String.format("+++DBG: Should expire on %s",
> expiresOn.getTime()));
> rep.setExpirationDate(expiresOn.getTime());
> return rep;
> }
>
> }
>
> This should give my application the ability to serve static resources
> set to expire in one year, which should be enough for caching
> purposes, by simply replacing the Directory code above with:
>
> ExpirableDirectoryResource dir = new
> ExpirableDirectoryResource(getContext(), "clap://system/res");
> router.attach("/res", dir);
>
> in my application's createInboundRoot() method.
>
> However, it's not working (Restlet 2.0M7). This is what I get in the logs:
>
> 02/02/2010 13:30:59 com.calenco.resource.FarExpiringDirectoryResource<init>
> INFO: +++DBG: Expiration date set to Wed Feb 02 13:30:59 ARST 2011
> 02/02/2010 13:30:59 org.restlet.engine.local.DirectoryServerResource doInit
> INFO: Converted target URI: clap://system/res/css/style.css
> 02/02/2010 13:30:59 org.restlet.engine.local.DirectoryServerResource
> getVariants
> INFO: Getting variants for : clap://system/res/css/style.css
> 02/02/2010 13:30:59 org.restlet.engine.log.LogFilter afterHandle
> INFO: 2010-02-02 13:30:59 0:0:0:0:0:0:0:1 [email protected]
> - -1 GET /res/css/style.css - 200 - 0
> 16 http://localhost:9000 Mozilla/5.0
> (X11; U; Linux x86_64; es-AR; rv:1.9.1.7) Gecko/20100106 Ubuntu/9.10
> (karmic) Firefox/3.5.7 http://localhost:9000/
> 02/02/2010 13:30:59 com.calenco.resource.FarExpiringDirectoryResource<init>
> INFO: +++DBG: Expiration date set to Wed Feb 02 13:30:59 ARST 2011
> 02/02/2010 13:30:59 org.restlet.engine.local.DirectoryServerResource doInit
> INFO: Converted target URI: clap://system/res/img/header.jpg
> 02/02/2010 13:30:59 org.restlet.engine.local.DirectoryServerResource
> getVariants
> INFO: Getting variants for : clap://system/res/img/header.jpg
> 02/02/2010 13:30:59 org.restlet.engine.log.LogFilter afterHandle
> INFO: 2010-02-02 13:30:59 0:0:0:0:0:0:0:1 [email protected]
> - -1 GET /res/img/header.jpg - 200 - 0
> 4http://localhost:9000 Mozilla/5.0
> (X11; U; Linux x86_64; es-AR; rv:1.9.1.7) Gecko/20100106 Ubuntu/9.10
> (karmic) Firefox/3.5.7 http://localhost:9000/res/css/style.css
>
> A few things can be seen there:
>
> - The new resources are being used, because the "Expiration date set
> to..." message shows that the FarExpiringDirectoryResource is being
> instantiated with the correct date set (1 year from the time of the
> request)
> - The get() handler for FarExpiringDirectoryResource is not being
> called, only its parent (DirectoryServerResource) one is, thus giving
> you instant-expiring representations instead of far-expiring ones
>
> So, why isn't the FarExpiringDirectoryResource#get being called
> instead of DirectoryServerResource#get?
>
> Thanks for reading up to here and thanks in advance for your help.
>
>
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