This class is used by the PDP to handle resource scopes other than Immediate. In the case of a scope of Children or Descendants, the PDP needs a list of Resource Ids to evaluate, each of which will get its own Result. Like the PolicyFinder, this is not tied in any way to the rest of the PDP code, and could be provided as a stand-alone resource.
This class basically is a coordinator that asks each module in turn if it can handle the given identifier. Evaluation proceeds in order through the given modules, and once a module returns a non-empty response (whether or not it contains any errors or only errors), the evaluation is finished and the result is returned. One of the issues here is ordering, since a given resource may look to several modules like something that they can handle. So, you must be careful when assigning to ordering of the modules in this finder.
Note that in release 1.2 the interfaces were updated to include the evaluation context. In the next major release the interfaces without the context information will be removed, but for now both exist. This means that if this finder is called with the context, then only the methods in ResourceFinderModule supporting the context will be called (and likewise only the methods without context will be called when this finder is called without the context). In practice this means that the methods with context will always get invoked, since this is what the default PDP implementation calls.
@since 1.0
@author Seth ProctorAdding generic type support by Christian Mueller (geotools)