Allow users of DefaultConfigurationBuilder to configure the class name of the CombinedConfiguration to create and to configure providers

• Key: CONFIGURATION-337
• Type: Improvement
• Status: Closed
• Resolution: Fixed
• Priority: Major
• Assignee: Oliver Heger
• Reporter: Ralph Goers
• Affects Version/s: 1.6
• Fix Version/s: 1.6

Description

This enhancement allows config-class to be specified on the result element. The specified class must extend CombinedConfiguration.

This enhancment allows ConfigurationProviders to be configured by adding

<providers>
<provider tag="myprovider" config-class="MyProviderClass"/>
</providers

to the header.

Comments

[Ralph Goers]

The patch to implement this feature along with unit tests.

[Oliver Heger]

Ralph,

many thanks for your contribution. I had a look at the patch, and this is really some cool stuff. I am happy to apply it, but have the following minor suggestions:

• So far the providers' classes are directly loaded, and instances are created through reflection. Why not reusing our bean declaration mechanism for this purpose? This would also allow setting properties on the provider objects created.

• I would prefer if ExtendedCombinedConfiguration, which is used for testing the config-class attribute for the resulting configuration, was an inner class of TestDefaultConfigurationBuilder. It is only used in this test class and does not deserve the status of a top level class.

What do you think?

[Ralph Goers]

I am fine with both of these suggestions. I didn't use the bean declaration mechanism primarily because I hadn't looked at how that worked when I wrote that part of the patch.

[Ralph Goers]

Updated patch with requested changes.

Patch applied in revision 701654.

It could even be slightly simplified. As it turned out, defining a custom CombinedConfiguration class as resulting configuration is already supported. This is due to the bean definition mechanism, which automatically looks for a config-class attribute and evaluates it if present; otherwise the default class passed to the BeanHelper is used. Also at the creation of the providers there is no need to explicitly specify the provider class because it is found automatically by the XMLBeanDeclaration.

Leaving open until the patch was ported to the configuration-2 branch.

[Ralph Goers]

Thanks. I should have looked at the javadoc for createBean.

Also, I noticed you cleaned up the unit test a little bit. After looking at it it seems you could have also gotten rid of the creation of the new DefaultConfigurationBuilder in testExtendedClass since that happens in setUp.

[Oliver Heger]

Thanks for the spot. I missed this one. I updated the test correspondingly.

[Oliver Heger]

The patch was also applied to the configuration2 branch.

[Ralph Goers]

This is part of the 1.6 release.