Hi everyone, We are developing a new product which consist of a server and several mobile clients. We chose RESTlet to develop both the server (hosted on Google AppEngine) and the Android client part and we are running into several problems with it.
Communication happens through some POJOs which are de/serialized to JSON by ConverterService (we are using the "Jackson" extension). We are using an approach similar to the one described in "First Application" [1] tutorial: POJOs + interfaces + ServerResources implementing the interfaces and ClientResources wrap()'ing the interfaces. The Android client sends raw Java serialization data (application/x-java-serialized-object) instead. Everything works fine on the local AppEngine's development server. But, as soon as we deploy it to GAE, both the test suite and the client don't work. On the server side, the deserialized POJOs become NULs, thus we get a lot of Null-pointer execptions. I managed to track the source of the problem to the "Transfer-Encoding: chunked" header added by the RESTlet ClientResource. After some tests (done with curl) it seems that the server somehow trashes variable-length requests and can't deserialize the JSON representation sent this way. Sending a fixed-length request with a defined Content-Length header doesn't trigger the problem and the server works fine. Because of this, the Android client doesn't work either since it sends the serialized objects wrapped in a chunked request. As a work-around I tried to force the client to send JSON representations but I can't seem to be able to instruct the ConverterService to prefer JSON instead of the binary representation. We don't know if this is a RESTlet bug or a problem on GAE side (but I suppose it's their fault). So far I have envisioned only two ways to overcome this situation: - Write an alternative JacksonRepresentation (+ Converter) which sends fixed-length entities so that RESTlet doesn't wrap them in a chunked request and figure out how to instruct the ConverterService on Android to use it. This is probably the cleanest way (provided that ConverterService on Android works as expected). - Throw away the POJOs (on client side, at least), use StringRepresentations everywhere and manually serialize/deserialize the POJOs in the request handler. Any idea? Regards, Lorenzo V. _________ [1] http://wiki.restlet.org/docs_2.0/13-restlet/21-restlet/318-restlet/303-restlet.html ------------------------------------------------------ http://restlet.tigris.org/ds/viewMessage.do?dsForumId=4447&dsMessageId=2701359
