HV-1950 Suppress java.lang.NoClassDefFoundError: com/sun/el/ExpressionFactoryImpl

[quaff]

It will mislead user that hibernate validator will rely on particular EL implementation.

see https://hibernate.atlassian.net/browse/HV-1950.

[marko-bekhta]

Hey, thanks for submitting this PR.

    @CallerSensitive
    public static Class<?> forName(String className)
                throws ClassNotFoundException {
        Class<?> caller = Reflection.getCallerClass();
        return forName0(className, true, ClassLoader.getClassLoader(caller), caller);
    }

Since that's how the Class.forName is implemented wouldn't we just end up having the same class loader as in the very first try of this buildExpressionFactory()? This part:

if ( canLoadExpressionFactory() ) {
			ExpressionFactory expressionFactory = ELManager.getExpressionFactory();
			LOG.debug( "Loaded expression factory via original TCCL" );
			return expressionFactory;
		}

It would also be nice if the changes were accompanied by a test case; thanks!

[gsmet]

I would refrain from changing the logic in there. It is very brittle and we worked around multiple issues with OSGi and the modular classpath from WildFly.

[quaff]

I've revert to ExpressionFactoryImpl.class.getClassLoader(), just catch NoClassDefFoundError and ignore it.

[quaff]

Since that's how the Class.forName is implemented wouldn't we just end up having the same class loader as in the very first try of this buildExpressionFactory()? This part:

ExpressionFactoryImpl is load from ResourceBundleMessageInterpolator's classloader, but its actual classloader could be another classloader due to delegation.