On Mon, 2006-11-27 at 02:55 -0800, Mahesh.Kannan wrote:
>
> Jason.Huang_at_Sun.COM wrote:
>
> > Hi, All
> >
> > I have some questions about the implementation of EJB container.
> >
> > I have a Stateless bean in EJB2.x style which has a remote business
> > method like:
> > -----------------------------------------------------
> >
> > public String sayHi() {
> > Thread.dumpStack();
> > return "Foo";
> > }
> > -----------------------------------------------------
> >
> > I call the EJB from a standalone client, the output of the
> > Thread.dumpStack(); is:
> > ------------------------------------------------
> > java.lang.Exception: Stack trace
> > at java.lang.Thread.dumpStack(Thread.java:1158)
> > at ejb.demo.helloworld2.HelloWorldBean.sayHi(HelloWorldBean.java:63)
> > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> > at
> > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
> >
> > at
> > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> >
> > at java.lang.reflect.Method.invoke(Method.java:585)
> > at
> > com.sun.enterprise.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1051)
> >
> > at
> > com.sun.enterprise.security.SecurityUtil.invoke(SecurityUtil.java:165)
> > at
> > com.sun.ejb.containers.BaseContainer.invokeTargetBeanMethod(BaseContainer.java:2812)
> >
> > at
> > com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:3896)
> > at
> > com.sun.ejb.containers.EJBObjectInvocationHandler.invoke(EJBObjectInvocationHandler.java:190)
> >
> > at
> > com.sun.ejb.containers.EJBObjectInvocationHandler.invoke(EJBObjectInvocationHandler.java:107)
> >
> > at $Proxy88.sayHi(Unknown Source)
> > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> > at
> > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
> >
> > at
> > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> >
> > at java.lang.reflect.Method.invoke(Method.java:585)
> > at
> > com.sun.corba.ee.impl.presentation.rmi.ReflectiveTie._invoke(Unknown
> > Source)
> > at
> > com.sun.corba.ee.impl.protocol.CorbaServerRequestDispatcherImpl.dispatchToServant(Unknown
> > Source)
> > at
> > com.sun.corba.ee.impl.protocol.CorbaServerRequestDispatcherImpl.dispatch(Unknown
> > Source)
> > at
> > com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequestRequest(Unknown
> > Source)
> > at
> > com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequest(Unknown
> > Source)
> > at
> > com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleInput(Unknown
> > Source)
> > at
> > com.sun.corba.ee.impl.protocol.giopmsgheaders.RequestMessage_1_2.callback(Unknown
> > Source)
> > at
> > com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequest(Unknown
> > Source)
> > at
> > com.sun.corba.ee.impl.transport.SocketOrChannelConnectionImpl.dispatch(Unknown
> > Source)
> > at
> > com.sun.corba.ee.impl.transport.SocketOrChannelConnectionImpl.doWork(Unknown
> > Source)
> > at
> > com.sun.corba.ee.impl.orbutil.threadpool.ThreadPoolImpl$WorkerThread.run(Unknown
> > Source)
> > ------------------------------------------------
> > In the stack trace, I found class Proxy88 is called. However I cannot
> > find the code which generate Proxy88.
>
> This is an instance of JDK Proxy itself.
>
> > I've read some codes in the package com.sun.ejb.codegen.
> > According to my understanding, I assume that the WrapperGenerator
> > will help generate the EJB Object implementation(XXXX_EJBObjectImpl),
> > and this remote object will delegate the method to bean object itself.
> > However I cannot find where the WrapperGenerator is used.
> >
> WrapperGenerators *were* used previously to generate implementation
> classes for EJB 2.x impl classes.
>
> > I found the input parameters for the rmic are the Remote and Remote
> > Home interface, which can generate the stub classes. Where can I find
> > the tie classes?
>
> rmic -iiop generates both stub and tie classes. However, glassfish
> doesn't use rmic anymore. It uses dynamic class generation techniques to
> generate stub and tie classes.
>
> The container now uses dynamic class generators to generate true IIOP
> classes. For example, RemoteGenerator and Remote30WrapperGenerator are
> now used by the container to dynamically generate the required iiop
> classes dynamically.
>
>
>
> > Coud you give some suggestions or documents on the EJB code generation?
I'll address the CORBA side of this. The dynamic RMI-IIOP code in CORBA
uses BCEL to generate
a stub dynamically from the remote interface. That's all that's needed
for EJB 2.x. However,
EJB 3 requires in addition the generation of the remote interface from
the business interface,
and also an adapter class that wraps exceptions and converts them from
the RMI world
to EJB 3. In all cases, there are no generated ties: we just use a
ReflectiveTie class in the
ORB for all Tie functions (which also relies on the dynamic RMI-IIOP
infrastructure to determine
how to unmarshal parameters and marshal the result). There is
documentation on
dynamic RMI-IIOP available at:
https://glassfish-corba.dev.java.net/design/dynamic_rmi_iiop.htm
The GlassFish ORB also supplies the codegen library that EJB 3 uses to
generate the remote
interface and adapter class. The only docs available for codegen are
the JavaDocs,
which unfortunately do not appear where they ought to in the
glassfish-corba project.
If you are really interested, you could build the JavaDocs from the
glassfish-corba project,
then look at the classes in the com.sun.corba.se.spi.codegen package
(particularly in the
Wrapper class).
Ken.