[CONFIGURATION-441] CompositeConfiguration does not resolve referenced properties correctly

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Invalid
• Affects Version/s: 1.5
• Fix Version/s: 1.7
• Component/s: Interpolation

Environment

all

• Assignee: Unassigned
• Reporter: Fabien Nisol
• Created: 30/Mar/11 18:19
• Updated: 08/Sep/11 09:20
• Resolved: 06/Apr/11 10:14

Description

Imagine a composite configuration consisting of

config_x : configuration one
property.one=one
property.two=two

config_y : configuration two
property.one.ref=${property.one}

When getProperty() is called on a CompositeConfiguration, property interpolation does not work if a property in config_x refers to a property in config_y, in the example, property.one.ref won't translate into "one"

This seems to be caused by the getProperty() implementation of CompositeConfiguration

CompositeConfiguration.getProperty(String)

/**
     * Read property from underlying composite
     *
     * @param key key to use for mapping
     *
     * @return object associated with the given configuration key.
     */
    public Object getProperty(String key)
    {
        Configuration firstMatchingConfiguration = null;
        for (Iterator i = configList.iterator(); i.hasNext();)
        {
            Configuration config = (Configuration) i.next();
            if (config.containsKey(key))
            {
                firstMatchingConfiguration = config;
                break;
            }
        }

        if (firstMatchingConfiguration != null)
        {
            return firstMatchingConfiguration.getProperty(key);
        }
        else
        {
            return null;
        }
    }

The methods finds the first configuration containing the key, and delegates the call to that particular configuration.

A possible fix would be to try interpolation against every configuration until an interpolation succeed.