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/thread/c4fb4f414c425ca1 D.
On Jun 16, 12:12 am, Jeff Schnitzer <j...@infohazard.org> 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 <dilbert.elbo...@gmail.com> 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 <j...@infohazard.org> 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 <dilbert.elbo...@gmail.com> 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 <j...@infohazard.org> wrote: > >> >> Perhaps try posting the stacktrace to the hessian-interest list? > >> >> Someone (possibly me) might be able to fix this issue. > > >> >> Jeff > > >> >> On Thu, Jun 10, 2010 at 9:13 AM, dilbert <dilbert.elbo...@gmail.com> > >> >> wrote: > >> >> > First I'd like to explain what I mean by RPC. I'd like to be able to > >> >> > write interfaces like this (simple Java interface): > > >> >> > public interface EchoService { > >> >> > String echo(String message); > >> >> > } > > >> >> > The framework would allow the creation of client classes that would > >> >> > handle the serialization from/to the RPC service. Of course the > >> >> > framework should support the serialization of ArrayLists, HashMaps and > >> >> > other collections and should also support the serialization of objects > >> >> > marked with the "java.io.Serializable" interface (or some other > >> >> > interface). > >> >> > We would create the RPC Client this way: > > >> >> > EchoService echoService = > >> >> > RpcClientFactory.createInstance(EchoService.class,"http://bla.com/ > > ... > > 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 google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
