This may be a new shiny valid alternative: http://googlewebtoolkit.blogspot.com/2010/07/gwtrpccommlayer-extending-gwt-rpc-to-do.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed:+blogspot/NWLT+(Google+Web+Toolkit+Blog)&utm_content=Google+Reader
I wonder if it will work on Android. On Jun 16, 10:44 am, dilbert <[email protected]> wrote: > I posted a new bug report:http://bugs.caucho.com/view.php?id=4080 > I would like to move further discussion about this issue to the proper > place:http://groups.google.com/group/google-appengine-java/browse_thread/th... > D. > > On Jun 16, 12:12 am, Jeff Schnitzer <[email protected]> wrote: > > > I would close the old issue and create a new one cut down to just the > > exception issue. > > > *Are* there any serious RPC alternatives right now? Sounds like > > gwt-syncproxy isn't quite ready for prime time (and makes me nervous > > since it's not using a published protocol), the *-WS stuff is a > > trainwreck, and *-RS is not really convenient as an RPC layer. I > > would like alternatives. > > > Jeff > > > On Tue, Jun 15, 2010 at 2:41 PM, dilbert <[email protected]> wrote: > > > At the time I thought the issues were connected since they threw the > > > same exception so I posted them together. So should I post the issue > > > with exceptions again on the Caucho bug tracker? If this issue is > > > solved I would recommend Hessian as the best RPC mechanism for GAE at > > > this time. > > > Apologies to other readers for the offtopic with bugs. > > > D. > > > > On Jun 15, 11:24 pm, Jeff Schnitzer <[email protected]> wrote: > > >> I think you did yourself a disservice by wrapping these two issues > > >> into a single message - it ends up being way too much text to read and > > >> otherwise eager volunteers just skip it. > > > >> The first issue looks like you're not detaching your entities before > > >> serializing them. This is a JDO issue. I suggest dropping JDO and > > >> using something simpler like Objectify ;-) > > > >> The issue with exceptions looks more serious. This is something that > > >> will need to be fixed in Hessian (or your custom serializer). If you > > >> cut down your issue to just this, you might get better results from > > >> Caucho. > > > >> Jeff > > > >> On Tue, Jun 15, 2010 at 1:55 PM, dilbert <[email protected]> > > >> wrote: > > >> > Hi Jeff. I was hoping to hear from You since I saw that You solved > > >> > some GAE issues on the hessian-interest list. I already posted the > > >> > issue on the hessian-interest list here: > > >> >http://maillist.caucho.com/pipermail/hessian-interest/2010-June/00090... > > >> > I also posted several forum questions: > > >> >http://forum.caucho.com/showthread.php?t=9999 > > >> >http://groups.google.com/group/google-appengine-java/browse_thread/th... > > >> > And a few bug reports: > > >> >http://bugs.caucho.com/view.php?id=4061 > > >> >http://code.google.com/p/googleappengine/issues/detail?id=3305 > > >> > The posts actually describe two issues one with arraylist > > >> > serialization and the other with exception serialization. The posts > > >> > also include test projects with code that reproduces the issues. I > > >> > also managed to solve the issue today by using a custom serializer. > > >> > Here is how. First the Serializer: > > > >> > public class ThrowableSerializer extends AbstractSerializer { > > >> > �...@override > > >> > public void writeObject(Object obj, AbstractHessianOutput out) > > >> > throws IOException { > > >> > if (obj != null) { > > >> > final Class cl = obj.getClass(); > > >> > if (out.addRef(obj)) > > >> > return; > > >> > int ref = out.writeObjectBegin(cl.getName()); > > >> > Throwable tr = (Throwable) obj; > > >> > ByteArrayOutputStream bos = new ByteArrayOutputStream(); > > >> > ObjectOutputStream oos = new ObjectOutputStream(bos); > > >> > try { > > >> > oos.writeObject(tr); > > > >> > if (ref < -1) { > > >> > out.writeString("value"); > > >> > out.writeBytes(bos.toByteArray()); > > >> > out.writeMapEnd(); > > >> > } else { > > >> > if (ref == -1) { > > >> > out.writeInt(1); > > >> > out.writeString("value"); > > >> > out.writeObjectBegin(cl.getName()); > > >> > } > > >> > out.writeBytes(bos.toByteArray()); > > >> > } > > >> > } finally { > > >> > oos.close(); > > >> > bos.close(); > > >> > } > > >> > } else > > >> > out.writeNull(); > > >> > } > > >> > } > > > >> > The other class we need is the Deserializer: > > >> > public class ThrowableDeserializer extends AbstractDeserializer { > > >> > //private static final Logger l = > > >> > Logger.getLogger(ThrowableDeserializer.class.getName()); > > > >> > �...@override > > >> > public Class getType() { > > >> > return Throwable.class; > > >> > } > > > >> > �...@override > > >> > public Object readMap(AbstractHessianInput in) throws IOException > > >> > { > > >> > int ref = in.addRef(null); > > >> > byte[] initValue = null; > > >> > while (!in.isEnd()) { > > >> > String key = in.readString(); > > > >> > if (key.equals("value")) > > >> > initValue = in.readBytes(); > > >> > else > > >> > in.readString(); > > >> > } > > > >> > in.readMapEnd(); > > >> > ByteArrayInputStream bis = new > > >> > ByteArrayInputStream(initValue); > > >> > ObjectInputStream ois = new ObjectInputStream(bis); > > >> > try { > > >> > Object value = ois.readObject(); > > >> > in.setRef(ref, value); > > >> > return value; > > >> > } catch (ClassNotFoundException e) { > > >> > throw new RuntimeException(e); > > >> > } finally { > > >> > ois.close(); > > >> > bis.close(); > > >> > } > > >> > } > > > >> > �...@override > > >> > public Object readObject(AbstractHessianInput in, Object[] > > >> > fieldNames) > > >> > throws IOException { > > >> > int ref = in.addRef(null); > > >> > byte[] initValue = null; > > >> > for (Object o : fieldNames) { > > >> > if (o instanceof String) { > > >> > final String key = (String) o; > > >> > if (key.equals("value")) > > >> > initValue = in.readBytes(); > > >> > else > > >> > in.readObject(); > > >> > } > > >> > } > > >> > ByteArrayInputStream bis = new > > >> > ByteArrayInputStream(initValue); > > >> > ObjectInputStream ois = new ObjectInputStream(bis); > > >> > try { > > >> > Object value = ois.readObject(); > > >> > in.setRef(ref, value); > > >> > return value; > > >> > } catch (ClassNotFoundException e) { > > >> > throw new RuntimeException(e); > > >> > } finally { > > >> > ois.close(); > > >> > bis.close(); > > >> > } > > >> > } > > >> > } > > >> > I'm not sure if the readMap part is actually needed since I rearranged > > >> > this code from another example. Also, a ThrowableSerializerFactory is > > >> > needed: > > >> > public class ThrowableSerializerFactory extends > > >> > AbstractSerializerFactory { > > >> > �...@override > > >> > public Serializer getSerializer(Class cl) throws > > >> > HessianProtocolException { > > >> > if (Throwable.class.isAssignableFrom(cl)) { > > >> > return new ThrowableSerializer(); > > >> > } > > >> > return null; > > >> > } > > > >> > �...@override > > >> > public Deserializer getDeserializer(Class cl) throws > > >> > HessianProtocolException { > > >> > if (Throwable.class.isAssignableFrom(cl)) { > > >> > return new ThrowableDeserializer(); > > >> > } > > >> > return null; > > >> > } > > >> > } > > >> > What this code essentially does is take a Throwable (which implements > > >> > Serializable), serializes it to a byte[] and pushes it over to the > > >> > other side. This serialization does not use the problematic > > >> > setAccessible method (like com.caucho.hessian.io.ThrowableSerializer) > > >> > and works correctly on App engine (I tested it). The only part left to > > >> > do is to plug all this into the servlet and the client. Here is how to > > >> > do it on the servlet: > > >> > public class Service extends HessianServlet implements IService { > > >> > �...@override > > >> > public void init(ServletConfig config) throws ServletException { > > >> > super.init(config); > > >> > getSerializerFactory().addFactory(new > > >> > ThrowableSerializerFactory()); > > >> > } > > >> > // implement IService methods... > > >> > } > > > >> > And here is how to do it on the client: > > >> > String url = "http://whatever.appspot.com/service";; > > >> > HessianProxyFactory factory = new HessianProxyFactory(); > > >> > factory.getSerializerFactory().addFactory(new > > >> > ThrowableSerializerFactory()); > > >> > IService service = (IService) factory.create(IService.class, url); > > > >> > I would like to hear your opinion on this solution. Do You see any > > >> > problems with it? Also, when could we expect to see a solution in > > >> > Hessian? If You need any other information please ask. Thank You for > > >> > Your time. > > > >> > D. > > >> > On Jun 15, 7:34 pm, Jeff Schnitzer <[email protected]> wrote: > > >> >> Perhaps try posting the stacktrace to the hessian-interest list? > > >> >> Someone (possibly me) might be able to fix this issue. > > ... > > read more » -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
