[jacorb-developer] FYI - ORB classloader change in Java 7u55, Java 8u5 - Suggestions needed

[Timothy Astle]

I've been in contact with the author of the change in the JRE.  He's 
been very cordial.

When I contacted him about the change, this was the first reply:

"The loading of a third party singleton ORB has changed. It is loaded by 
the system loader only, thus requiring that
the specified class is on the application's classpath. Thus, when 
-Dorg.omg.CORBA.ORBSingletonClass is specified
then classpath variable needs to be amended, also. A CORBA compliant 
singleton ORB is essentially a TypeCode factory.
Its instantiation is via the no-args ORB.init() method call. As it is a 
singleton, it should be loaded with appropriate privileges.
The same functionality should be available from a full ORB 
(org.omg.CORBA.ORBClass).

As such, it is not a bug per se. But the absence of relevant release 
note document is a problem.
Unfortunately, as this change had generated a number of JBS issues, we 
noticed that a relevant release note was not created.
This is being rectified at present."

I then asked for a recommendationbecause I have a simple WAR deployment 
requirement, and he replied as follows:

"I would ask that you bear with us, a while on this, as we address this 
backward compatibility issue, and look
to solve the issues raised.  We were aware that there might be some 
compatibility issue, and had marked it as a risk,
but as  the Singleton ORB is limited in scope, and functionality we 
anticipated that it would be reasonably OK to
proceed with the refactored loading strategy. The anticipation was that 
deployments could modify the classpath,
and that TCCL loading of the full ORB would be sufficient in most cases.

In any case, we looking into this ORBSingleton conundrum, and will get 
back to shortly on this."

I might be reading into this, but it seems like they're going to address 
the problem.

If I get any more information, I'll be happy to pass it along.

Tim




On 09/05/2014 7:48 PM, Ravindra Kumar wrote:
> Hi
> Apparently i have also encountered the same issue. It is a bug definitely.
>
> thanks
> rainvdra
>
>
> On Sat, May 10, 2014 at 12:42 AM, Timothy Astle <timothy.astle at caris.com>wrote:
>
>> http://hg.openjdk.java.net/jdk7u/jdk7u60/corba/rev/a8d27c3fc4e4
>>
>> The change looks to be introduced into:
>> * Java 8 update 5
>> * Java 7 update 55
>> * Java 6 (looks like it was backported there too)
>>
>> It appears that people are just starting to encounter this issue as they
>> update their JREs:
>> * https://java.net/jira/browse/GLASSFISH-21047
>> * http://stackoverflow.com/questions/23225144/java-7u55-
>> eclipse-system-fragment-classloader
>>
>> It can affect web applications that are distributing JacORB within the web
>> application itself.  Oracle changed the classloader that searches for the
>> ORBSingletonClass, so now the implementation class must be on the System
>> classpath, not the web application's classpath, else the JRE will not find
>> the implementation.  You can see how this applies to servlet containers
>> here: http://tomcat.apache.org/tomcat-7.0-doc/class-loader-howto.html
>>
>> People will most likely see this exception when it is encountered:
>>
>> Caused by: org.omg.CORBA.INITIALIZE: can't instantiate default ORB
>> implementation com.sun.corba.ee.impl.orb.ORBSingleton vmcid: 0x0 minor
>> code: 0 completed: No
>> at org.omg.CORBA.ORB.create_impl_with_systemclassloader(ORB.java:309)
>> at org.omg.CORBA.ORB.init(ORB.java:294)
>>
>> I was in contact with the committer from Oracle today.  He says this is
>> not a bug, but they admit that the documentation on the change was poor and
>> they've been getting a fair amount of issues filed about it in their bug
>> database (http://bugs.java.com).  I believe they aim on remedying this.
>>
>> So I'm left with a question to the experienced JacORB developers:
>>
>> Is there a way that I can distribute JacORB within a WAR file and have it
>> work given the breaking change in the JRE?  I was basically just doing this:
>>
>> Properties props = new Properties();
>> props.setProperty("org.omg.CORBA.ORBClass", "org.jacorb.orb.ORB");
>> props.setProperty("org.omg.CORBA.ORBSingletonClass",
>> "org.jacorb.orb.ORBSingleton");
>> org.jacorb.orb.ORB orb = (org.jacorb.orb.ORB) org.omg.CORBA.ORB.init(args,
>> props);
>>
>> I know the JacORB docs always mention supplying the ORB to the
>> bootclasspath (http://www.jacorb.org/TomcatHowto.html), but I didn't seem
>> to have any problems just bundling it into the WAR itself.
>>
>> Any tips would be appreciated,
>>
>> --
>> Tim Astle
>> _______________________________________________
>> jacorb-developer maillist  -  jacorb-developer at lists.spline.
>> inf.fu-berlin.de
>> https://lists.spline.inf.fu-berlin.de/mailman/listinfo/jacorb-developer
>>
> _______________________________________________
> jacorb-developer maillist  -  jacorb-developer at lists.spline.inf.fu-berlin.de
> https://lists.spline.inf.fu-berlin.de/mailman/listinfo/jacorb-developer
>
>

-- 
Tim Astle
Development Manager
Web Technologies

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