ognl 3.4.5 - Issue with using custom class loader in getValue

[davsclaus]

At Apache Camel we have a camel-ognl module
https://github.com/apache/camel/tree/main/components/camel-ognl

When we upgrade from 3.4.4 to 3.4.5 we had an unit test error in one of our tests.
https://github.com/apache/camel/blob/main/components/camel-ognl/src/test/java/org/apache/camel/language/ognl/OgnlTest.java#L48

At first sight I suspect its this change
#337

in the getValue method, that somehow the custom classloader that Camel will provide in the unit test is not being in use.

The custom class loader is part of the test
https://github.com/apache/camel/blob/main/components/camel-ognl/src/test/java/org/apache/camel/language/ognl/MyClassResolver.java#L30

where the classloader will now correctly fix the classname and load the class (notice the Animal1 vs Animal) in the name.

The camel code that creates the ognl context and invokes ognl from camel in that test is executing this code
https://github.com/apache/camel/blob/main/components/camel-ognl/src/main/java/org/apache/camel/language/ognl/OgnlExpression.java#L53

[davsclaus]

We made a workaround so we can use 3.4.5 but have it work with the test
apache/camel@6f7d168

[lukaszlenart]

Thanks for reporting this, yet I'm not sure if I understand the problem. In your code

exchange.getContext().setClassResolver(new MyClassResolver(context));

should getContext() and context be the same? And they are changed because of #337 ?

[davsclaus]

Thanks for reporting this, yet I'm not sure if I understand the problem. In your code

exchange.getContext().setClassResolver(new MyClassResolver(context));

should getContext() and context be the same? And they are changed because of #337 ?

This is pure Apache Camel code (context is not Ognl context here). This code is what setup Camel to use that custom hacked classloader we use in the unit test.

[lukaszlenart]

Hm... so why does it fail? I don't see a connection with the change and OGNL :(

[davsclaus]

Hm... so why does it fail? I don't see a connection with the change and OGNL :(

I think its this code change in src/main/java/ognl/Ognl.java (link to PR in top) see the code changes in getValue.

I would assume that ognl when attempting to load the class Animal1 does not call the custom class loader provided by Camel but maybe mistakenly uses the default classloader from Ognl due to changes in getValue.

[davsclaus]

So its maybe due to this change / wrapping

OgnlContext ognlContext = addDefaultContext(root, context);

[davsclaus]

My gut feeling is that addDefaultContext(root, context); somehow causes ognl to not use my custom classloader but instead the default from ognl instead. So maybe that code should somehow take into account if the custom context instance have custom classloader (and maybe other settings) then they should be used first.

[lukaszlenart]

@davsclaus please review the linked PR, it should solve the problem.