Introducing dummy shared library for servicemix-camel component that can be built by users for additional component.

[Ulhas Bhole]

Hi All,
I was recently caught by the ClassCastException even though the class 
being casted was of same type while using servcemix-camel component on 
redeployment scenario.

The problem was due to the class I was casting was loaded by Service 
Unit's class loader and redeploy or deploying another SA using  same 
camel component (camel-cxf in this case) was not happy about it and 
throw ClassCastException.

I was able to get around this problem by rebuilding servicemix-camel 
component but also was able to get it to work with creating new 
shared-library that contains additional components and servicemix-camel 
have dependency on this shared library. This would be much cleaner in 
terms of keeping the core servicemix-camel component unaffected from the 
additional camel components that user want to use.

Here is my proposal for the change: We can introduce new dummy 
servicemix-camel-shared library which may (or may not) contain some 
dependency or work like a place holder and servicemix-camel component 
add dependency on this new shared library.
In default case it can be just empty shared-library which later a use 
rebuild and add his own requirement (camel components) to it and this 
will be much cleaner than asking people to rebuild (and possibly 
pollute) servicemix-camel component.

I am interested in knowing people's reaction and possible problems that 
I may have overlooked. I am especially interested in comments on how it 
will affect servicemix 4 OSGi stuff.

Regards,

Ulhas Bhole