/*
* @(#)ResourceFinder.java
*
* Copyright 2003-2006 Sun Microsystems, Inc. All Rights Reserved.
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package com.sun.xacml.finder;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import com.sun.xacml.EvaluationCtx;
import com.sun.xacml.attr.AttributeValue;
/**
* 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.
* <p>
* 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.
* <p>
* 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
* <code>ResourceFinderModule</code> 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 Proctor
*
* Adding generic type support by Christian Mueller (geotools)
*/
public class ResourceFinder {
// the list of all modules
private List<ResourceFinderModule> allModules;
// the list of child modules
private List<ResourceFinderModule> childModules;
// the list of descendant modules
private List<ResourceFinderModule> descendantModules;
// the logger we'll use for all messages
private static final Logger logger = Logger.getLogger(ResourceFinder.class.getName());
/**
* Default constructor.
*/
public ResourceFinder() {
allModules = new ArrayList<ResourceFinderModule>();
childModules = new ArrayList<ResourceFinderModule>();
descendantModules = new ArrayList<ResourceFinderModule>();
}
/**
* Returns the ordered <code>List</code> of <code>ResourceFinderModule</code>s used by this
* class to find resources.
*
* @return a <code>List</code> of <code>ResourceFinderModule</code>s
*/
public List<ResourceFinderModule> getModules() {
return new ArrayList<ResourceFinderModule>(allModules);
}
/**
* Sets the ordered <code>List</code> of <code>ResourceFinderModule</code>s used by this class
* to find resources. The ordering will be maintained.
*
* @param modules
* a code>List</code> of <code>ResourceFinderModule</code>s
*/
public void setModules(List<ResourceFinderModule> modules) {
allModules = new ArrayList<ResourceFinderModule>(modules);
childModules = new ArrayList<ResourceFinderModule>();
descendantModules = new ArrayList<ResourceFinderModule>();
for (ResourceFinderModule module : modules) {
if (module.isChildSupported())
childModules.add(module);
if (module.isDescendantSupported())
descendantModules.add(module);
}
}
/**
* Finds Resource Ids using the Children scope, and returns all resolved identifiers as well as
* any errors that occurred. If no modules can handle the given Resource Id, then an empty
* result is returned.
*
* @param parentResourceId
* the root of the resources
* @param context
* the representation of the request data
*
* @return the result of looking for child resources
*/
public ResourceFinderResult findChildResources(AttributeValue parentResourceId,
EvaluationCtx context) {
for (ResourceFinderModule module : childModules) {
// ask the module to find the resources
ResourceFinderResult result = module.findChildResources(parentResourceId, context);
// if we found something, then always return that result
if (!result.isEmpty())
return result;
}
// no modules applied, so we return an empty result
if (logger.isLoggable(Level.INFO))
logger.info("No ResourceFinderModule existed to handle the " + "children of "
+ parentResourceId.encode());
return new ResourceFinderResult();
}
/**
* Finds Resource Ids using the Children scope, and returns all resolved identifiers as well as
* any errors that occurred. If no modules can handle the given Resource Id, then an empty
* result is returned.
*
* @deprecated As of version 1.2, replaced by
* {@link #findChildResources(AttributeValue,EvaluationCtx)}. This version does not
* provide the evaluation context to the modules, and will be removed in a future
* release.
*
* @param parentResourceId
* the root of the resources
*
* @return the result of looking for child resources
*/
public ResourceFinderResult findChildResources(AttributeValue parentResourceId) {
for (ResourceFinderModule module : childModules) {
// ask the module to find the resources
ResourceFinderResult result = module.findChildResources(parentResourceId);
// if we found something, then always return that result
if (!result.isEmpty())
return result;
}
// no modules applied, so we return an empty result
if (logger.isLoggable(Level.INFO))
logger.info("No ResourceFinderModule existed to handle the " + "children of "
+ parentResourceId.encode());
return new ResourceFinderResult();
}
/**
* Finds Resource Ids using the Descendants scope, and returns all resolved identifiers as well
* as any errors that occurred. If no modules can handle the given Resource Id, then an empty
* result is returned.
*
* @param parentResourceId
* the root of the resources
* @param context
* the representation of the request data
*
* @return the result of looking for descendant resources
*/
public ResourceFinderResult findDescendantResources(AttributeValue parentResourceId,
EvaluationCtx context) {
for (ResourceFinderModule module : descendantModules) {
// ask the module to find the resources
ResourceFinderResult result = module.findDescendantResources(parentResourceId, context);
// if we found something, then always return that result
if (!result.isEmpty())
return result;
}
// no modules applied, so we return an empty result
if (logger.isLoggable(Level.INFO))
logger.info("No ResourceFinderModule existed to handle the " + "descendants of "
+ parentResourceId.encode());
return new ResourceFinderResult();
}
/**
* Finds Resource Ids using the Descendants scope, and returns all resolved identifiers as well
* as any errors that occurred. If no modules can handle the given Resource Id, then an empty
* result is returned.
*
* @deprecated As of version 1.2, replaced by
* {@link #findDescendantResources(AttributeValue,EvaluationCtx)}. This version does
* not provide the evaluation context to the modules, and will be removed in a
* future release.
*
* @param parentResourceId
* the root of the resources
*
* @return the result of looking for child resources
*/
public ResourceFinderResult findDescendantResources(AttributeValue parentResourceId) {
for (ResourceFinderModule module : descendantModules) {
// ask the module to find the resources
ResourceFinderResult result = module.findDescendantResources(parentResourceId);
// if we found something, then always return that result
if (!result.isEmpty())
return result;
}
// no modules applied, so we return an empty result
if (logger.isLoggable(Level.INFO))
logger.info("No ResourceFinderModule existed to handle the " + "descendants of "
+ parentResourceId.encode());
return new ResourceFinderResult();
}
}