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

[Timothy Astle]

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