Thanks to a colleague, our patched version of the UPnP Base Driver now enables our OSGi applications to interoperate with several real devices that are standard UPnP Media Servers. Here are the classes and a description of the patch.
-------------------------- 1. Problem introduction Apache Felix UPnP Base Driver doesn't enable osgi applications to correctly browse (UPnP AV Content Directory Service action named browse) media files present on several devices in particular these ones: - Quartek Qbox - Philips Media Manager Sending the 'browse' action on the CDS service of these UPnP devices, Apache Felix UPnP Base Driver return a null object. 2. Problem analysis Sniffing http packet on the network, we see that these servers don't return all variable that the Apache Felix UPnP Base Driver wait for. Indeed, the Media Servers don't return the constant "CONTENT-LENGTH" in HTTP packets and the HTTP message parsing is obviously skipped by the cyberlink UPnP stack that is embedded in the Apache Felix UPnP Base Driver. Then the result of the "browse" action appears to be null. Although this problem was raised by the browse action that is critical in our application, the problem would probable have occured with other action calls. 3. Solution In order to resolve this problem, 2 Java(tm) classes in distinct packages are modified. The objective is first to initialize the "CONTENT-LENGTH" variable with a value big enough to contain all the possible values in UPnP applications. We declare a constant "conlen" initially assigned to 999999999. It thus simulates a big "CONTENT-LENGTH" for the browse action response to be parsed and the media controller can correctly browse Media servers. This change is made in HTTPPacket.set(InputStream in, boolean onlyHeaders) method (org.cybergarage.http package). The Action.postControlAction() method (org.cybergarage.upnp package) is also changed to use the new method HTTPPacket.set(). -- André
