[CONFIGURATION-442] SubsetConfiguration does not properly list attributes when a delimiter is set

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 1.6
• Fix Version/s: 1.7

Environment

all

• Assignee: Unassigned
• Reporter: Fabien Nisol
• Created: 31/Mar/11 14:48
• Updated: 08/Sep/11 09:20
• Resolved: 04/Aug/11 20:27

Description

imagine a XmlConfiguration like this:

<properties>
  <prop1>
    <prop2>
      <prop
         attr1="attr1"
         attr2="attr2"/>
    </prop2>
  </prop1>
</properties>

If subset get instanciated to the end of the hierarchy, with a specific delimiter, getKeys() won't return the correct keys:

...
XMLConfiguration config = new XMLConfiguration("test/test.xml");
Configuration subset = new SubsetConfiguration(config,"prop1.prop2.prop",".");
ConfigurationUtils.dump(subset, System.err);
...

gives the result:

@attr1]=null
@attr2]=null

it should give the result

[@attr1]=attr1
[@attr2]=attr2

The wrong dump is a side effect of the wrong implementation of the getChildKey method of SubsetConfiguration

 /**
     * Return the key in the subset configuration associated to the specified
     * key in the parent configuration.
     *
     * @param key The key in the parent configuration.
     * @return the key in the context of this subset configuration
     */
    protected String getChildKey(String key)
    {
        if (!key.startsWith(prefix))
        {
            throw new IllegalArgumentException("The parent key '" + key + "' is not in the subset.");
        }
        else
        {
            String modifiedKey = null;
            if (key.length() == prefix.length())
            {
                modifiedKey = "";
            }
            else
            {
                int i = prefix.length() + (delimiter != null ? delimiter.length() : 0);
                modifiedKey = key.substring(i);
            }

            return modifiedKey;
        }
    }

In this code, the else part is wrong. In a hierarchical configuration, the attribute delimiter is '[' and is removed here.

I think a more correct code would be :

/**
     * Return the key in the subset configuration associated to the specified
     * key in the parent configuration.
     *
     * @param key The key in the parent configuration.
     * @return the key in the context of this subset configuration
     */
    protected String getChildKey(String key)
    {
        if (!key.startsWith(prefix))
        {
            throw new IllegalArgumentException("The parent key '" + key + "' is not in the subset.");
        }
        else
        {
            String modifiedKey = null;
            if (key.length() == prefix.length())
            {
                modifiedKey = "";
            }
            else
            {
                modifiedKey = key.substring(prefix.length());
                if(delimiter!=null && modifiedKey.startsWith(delimiter))
                {
                    modifiedKey=modifiedKey.substring(delimiter.length());
                }
            }

            return modifiedKey;
        }
    }