AppEngine & Adobe BlazeDS (fix)

http://riaspringblaze.appspot.com

Hello,

Today I was able to get [ 'remoting only' ] BlazeDS (Community release 3.2.0.3978) to work on GAE, there seems to be an issue with current production GAE Servlet Container in which consequently causes BlazeDS class flex.messaging.io.amf.AbstractAmfInput.java when gets InputStream http request to throw an EOFException = (GAE 1339) resulting a context to resolve into MessageIOConstants.STATUS_NOTAMF in the flex.messaging.endpoints.amf.SerializationFilter class.

Here's my un-official 'fix' to the issue (which just worked for me this morning):

So couple things:

[1] First make sure config file services-config.xml has

false

, so it's not JMX managed (restricted by GAE)

false

false

[2] And Second: on BlazeDS source look for
flex.messaging.io.amf.AbstractAmfInput.java and replace line #58 (aprox)

this.in = new DataInputStream( in );
for
this.in = new DataInputStream( new java.io.BufferedInputStream( in ) );

So it would look as:

public abstract class AbstractAmfInput extends AmfIO implements ActionMessageInput
{
protected BeanProxy beanProxy = new BeanProxy();

protected DataInputStream in = null;

public AbstractAmfInput(SerializationContext context)
{
super(context);
}

public void setInputStream(InputStream in)
{
this.in = new DataInputStream( new BufferedInputStream( in ) );
}

... more

run BlazeDS ant build.xml in the following targets order : clean,sdk,common,core and replace the flex-messaging-core.jar into your application WEB-INF/lib folder, and deploy new war to GAE cloud.

The one I deployed also contains Spring (3.0.0.M2) and http://www.springsource.org/spring-flex(1.0.0.RC1)

Here's a demo app to demonstrate that it works:

(Note: Flex app is a proof of concept for demonstration purpose)

http://riaspringblaze.appspot.com

For those of you interested in compiled flex-messaging-core.jar drop a request in this blog's comments and I'll send it asap (do not send to my email directly, thanks).

Note: this is an unofficial community effort, so it is delivered 'as is' for you to experiment with ;-)

Update on 4/28/09, Another issue dealing with server sessions on messaging flex.messaging.endpoints.BaseHTTPEndpoint class detects a REQUEST_ATTR_DUPLICATE_SESSION_FLAG and throws "flex.messaging.request.DuplicateSessionDetected", it'd be nice if one could add to config file a no session management parameter. So for now on [line# 405 aprox] flex.messaging.endpoints.BaseHTTPEndpoint class I basically removed the duplicateSessionDetected check (temporarily) till this matures a bit more.

Which by the way on deployment [appengine-web.xml] descriptor you'll need:

true

Update on 09/28/2009: http://bugs.adobe.com/jira/browse/BLZ-444

I've received lots of emails asking me what libraries I'm packing under /WEB-INF/lib from G-sdk along with all other 3rd party dependencies, here's the list I have in my war (you may need more or less depending on what your app does):

martin@martin-ubuntu9 ~/projs/blazeappengine/war/WEB-INF/lib
$ ls -1
antlr-3.0.1.jar
aopalliance.jar
appengine-api-1.0-sdk-1.2.0.jar
asm-3.1.jar
aspectjrt.jar
backport-util-concurrent.jar
cfgatewayadapter.jar
cglib-2.2.jar
commons-beanutils.jar
commons-collections-3.1.jar
commons-fileupload-1.2.1.jar
commons-lang.jar
commons-logging-1.1.jar
concurrent.jar
datanucleus-appengine-1.0.0.final.jar
datanucleus-core-1.1.0.jar
datanucleus-jpa-1.1.0.jar
flex-messaging-common.jar
flex-messaging-core.jar
flex-messaging-opt.jar
flex-messaging-proxy.jar
flex-messaging-remoting.jar
geronimo-jpa_3.0_spec-1.1.1.jar
geronimo-jta_1.1_spec-1.1.1.jar
jackson-core-asl-0.9.9-6.jar
jdo2-api-2.3-SNAPSHOT.jar
org.springframework.aop-3.0.0.M2.jar
org.springframework.aspects-3.0.0.M2.jar
org.springframework.beans-3.0.0.M2.jar
org.springframework.context-3.0.0.M2.jar
org.springframework.context.support-3.0.0.M2.jar
org.springframework.core-3.0.0.M2.jar
org.springframework.expression-3.0.0.M2.jar
org.springframework.flex-1.0.0.RC1.jar
org.springframework.transaction-3.0.0.M2.jar
org.springframework.web-3.0.0.M2.jar
org.springframework.web.servlet-3.0.0.M2.jar
xalan.jar

Let me know how it goes.....

Also, I'd appreciate comments/feed-back/critiques on my blog as well so we can all share experiences / discoveries, thanks.
Cheers!