/*
* @(#)AttributeFinder.java
*
* Copyright 2003-2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistribution of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistribution in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
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package com.sun.xacml.finder;
import java.net.URI;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.w3c.dom.Node;
import com.sun.xacml.EvaluationCtx;
import com.sun.xacml.attr.AttributeDesignator;
import com.sun.xacml.attr.AttributeSelector;
import com.sun.xacml.attr.BagAttribute;
import com.sun.xacml.cond.EvaluationResult;
/**
* This class is used by the PDP to find attribute values that weren't originally supplied in the
* request. It can be called with the data supplied in {@link AttributeDesignator}s or
* {@link AttributeSelector}s. Because the modules in this finder may themselves need attribute data
* to search for attribute data, it's possible that the modules will look for values in the
* {@link EvaluationCtx}, which may in turn result in the invocation of this finder again, so module
* writers need to be careful about how they build their modules.
* <p>
* Note that unlike the PolicyFinder, this class doesn't always need to use every module it has to
* find a value. The ordering is maintained, however, so it will always start with the first module,
* and proceed in order until it finds a value or runs out of modules.
*
* @since 1.0
* @author Seth Proctor
*
* Adding generic type support by Christian Mueller (geotools)
*
*/
public class AttributeFinder {
// the list of all modules
private List<AttributeFinderModule> allModules;
//
private List<AttributeFinderModule> designatorModules;
//
private List<AttributeFinderModule> selectorModules;
// the logger we'll use for all messages
private static final Logger logger = Logger.getLogger(AttributeFinder.class.getName());
/**
* Default constructor.
*/
public AttributeFinder() {
allModules = new ArrayList<AttributeFinderModule>();
designatorModules = new ArrayList<AttributeFinderModule>();
selectorModules = new ArrayList<AttributeFinderModule>();
}
/**
* Returns the ordered list of {@link AttributeFinderModule}s used by this class to find
* attribute values.
*
* @return a list of <code>AttributeFinderModule</code>s
*/
public List<AttributeFinderModule> getModules() {
return new ArrayList<AttributeFinderModule>(allModules);
}
/**
* Sets the ordered list of {@link AttributeFinderModule}s used by this class to find attribute
* values. The ordering will be maintained.
*
* @param modules
* a list of <code>AttributeFinderModule</code>s
*/
public void setModules(List<AttributeFinderModule> modules) {
allModules = new ArrayList<AttributeFinderModule>(modules);
designatorModules = new ArrayList<AttributeFinderModule>();
selectorModules = new ArrayList<AttributeFinderModule>();
for (AttributeFinderModule module : modules) {
if (module.isDesignatorSupported())
designatorModules.add(module);
if (module.isSelectorSupported())
selectorModules.add(module);
}
}
/**
* Tries to find attribute values based on the given designator data. The result, if successful,
* will always contain a {@link BagAttribute}, even if only one value was found. If no values
* were found, but no other error occurred, an empty bag is returned.
*
* @param attributeType
* the datatype of the attributes to find
* @param attributeId
* the identifier of the attributes to find
* @param issuer
* the issuer of the attributes, or null if unspecified
* @param subjectCategory
* the category of the attribute if the designatorType is
* {@link AttributeDesignator#SUBJECT_TARGET}, otherwise null
* @param context
* the representation of the request data
* @param designatorType
* the type of designator as named by the *_TARGET fields in
* {@link AttributeDesignator}
*
* @return the result of attribute retrieval, which will be a bag of attributes or an error
*/
public EvaluationResult findAttribute(URI attributeType, URI attributeId, URI issuer,
URI subjectCategory, EvaluationCtx context, int designatorType) {
for (AttributeFinderModule module : designatorModules) {
// see if the module supports this type
Set<Integer> types = module.getSupportedDesignatorTypes();
if ((types == null) || (types.contains(new Integer(designatorType)))) {
// see if the module can find an attribute value
EvaluationResult result = module.findAttribute(attributeType, attributeId, issuer,
subjectCategory, context, designatorType);
// if there was an error, we stop right away
if (result.indeterminate()) {
if (logger.isLoggable(Level.INFO))
logger.info("Error while trying to resolve values: "
+ result.getStatus().getMessage());
return result;
}
// if the result wasn't empty, then return the result
BagAttribute bag = (BagAttribute) (result.getAttributeValue());
if (!bag.isEmpty())
return result;
}
}
// if we got here then there were no errors but there were also no
// matches, so we have to return an empty bag
if (logger.isLoggable(Level.FINE))
logger.fine("Failed to resolve any values for " + attributeId.toString());
return new EvaluationResult(BagAttribute.createEmptyBag(attributeType));
}
/**
* Tries to find attribute values based on the given selector data. The result, if successful,
* must always contain a {@link BagAttribute}, even if only one value was found. If no values
* were found, but no other error occurred, an empty bag is returned.
*
* @param contextPath
* the XPath expression to search against
* @param namespaceNode
* the DOM node defining namespace mappings to use, or null if mappings come from the
* context root
* @param attributeType
* the datatype of the attributes to find
* @param context
* the representation of the request data
* @param xpathVersion
* the XPath version to use
*
* @return the result of attribute retrieval, which will be a bag of attributes or an error
*/
public EvaluationResult findAttribute(String contextPath, Node namespaceNode,
URI attributeType, EvaluationCtx context, String xpathVersion) {
for (AttributeFinderModule module : selectorModules) {
// see if the module can find an attribute value
EvaluationResult result = module.findAttribute(contextPath, namespaceNode,
attributeType, context, xpathVersion);
// if there was an error, we stop right away
if (result.indeterminate()) {
if (logger.isLoggable(Level.INFO))
logger.info("Error while trying to resolve values: "
+ result.getStatus().getMessage());
return result;
}
// if the result wasn't empty, then return the result
BagAttribute bag = (BagAttribute) (result.getAttributeValue());
if (!bag.isEmpty())
return result;
}
// if we got here then there were no errors but there were also no
// matches, so we have to return an empty bag
if (logger.isLoggable(Level.FINE))
logger.fine("Failed to resolve any values for " + contextPath);
return new EvaluationResult(BagAttribute.createEmptyBag(attributeType));
}
}