/*
* @(#)ResourceFinderModule.java
*
* Copyright 2003-2004 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")
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*/
package com.sun.xacml.finder;
import com.sun.xacml.EvaluationCtx;
import com.sun.xacml.attr.AttributeValue;
/**
* This is the abstract class that all <code>ResourceFinder</code> modules
* extend. All methods have default values to represent that the given
* feature isn't supported by this module, so module writers needs only
* implement the methods for the features they're supporting.
*
* @since 1.0
* @author Seth Proctor
*/
public abstract class ResourceFinderModule
{
/**
* Returns this module's identifier. A module does not need to provide
* a unique identifier, but it is a good idea, especially in support of
* management software. Common identifiers would be the full package
* and class name (the default if this method isn't overridden), just the
* class name, or some other well-known string that identifies this class.
*
* @return this module's identifier
*/
public String getIdentifier() {
return getClass().getName();
}
/**
* Returns true if this module supports finding resources with the
* "Children" scope. By default this method returns false.
*
* @return true if the module supports the Children scope
*/
public boolean isChildSupported() {
return false;
}
/**
* Returns true if this module supports finding resources with the
* "Descendants" scope. By default this method returns false.
*
* @return true if the module supports the Descendants scope
*/
public boolean isDescendantSupported() {
return false;
}
/**
* Returns true if this module supports finding resources with the
* "XPath-expression" scope. By default this method returns false.
*
* @return true if the module supports the XPath-expression scope
*/
public boolean isXPathSupported() {
return false;
}
/**
* Returns true if this module supports finding resources with the
* "EntireHierarchy" scope. By default this method returns false.
*
* @return true if the module supports the EntireHierarchy scope
*/
public boolean isHierarchySupported() {
return false;
}
/**
* This is an experimental method that asks the module to invalidate any
* cache values it may contain. This is not used by any of the core
* processing code, but it may be used by management software that wants
* to have some control over these modules. Since a module is free to
* decide how or if it caches values, and whether it is capable of
* updating values once in a cache, a module is free to intrepret this
* message in any way it sees fit (including igoring the message). It
* is preferable, however, for a module to make every effort to clear
* any dynamically cached values it contains.
* <p>
* This method has been introduced to see what people think of this
* functionality, and how they would like to use it. It may be removed
* in future versions, or it may be changed to a more general
* message-passing system (if other useful messages are identified).
*
* @since 1.2
*/
public void invalidateCache() {
//not defined yet, for future extensions
}
/**
* Tries to find the child Resource Ids associated with the parent. If
* this module cannot handle the given identifier, then an empty result is
* returned, otherwise the result will always contain at least the
* parent Resource Id, either as a successfully resolved Resource Id or an
* error case, but never both.
*
* @param parentResourceId the parent resource identifier
* @param context the representation of the request data
*
* @return the result of finding child resources
*/
public ResourceFinderResult findChildResources(AttributeValue
parentResourceId,
EvaluationCtx context) {
return new ResourceFinderResult();
}
/**
* Tries to find the descendant Resource Ids associated with the parent. If
* this module cannot handle the given identifier, then an empty result is
* returned, otherwise the result will always contain at least the
* parent Resource Id, either as a successfuly resolved Resource Id or an
* error case, but never both.
*
* @param parentResourceId the parent resource identifier
* @param context the representation of the request data
*
* @return the result of finding descendant resources
*/
public ResourceFinderResult findDescendantResources(AttributeValue
parentResourceId,
EvaluationCtx
context) {
return new ResourceFinderResult();
}
/**
* Tries to find the Resource Ids identified by an XPath. If
* this module cannot handle the given identifier, then an empty result is
* returned, otherwise the result will contain the result of applying this
* XPath to the Content with id="Resource". This may be an empty result.
*
* @param xpathResourceId the parent resource identifier
* @param context the representation of the request data
*
* @return the result of finding descendant resources
*/
public ResourceFinderResult findXPathResources(
AttributeValue xpathResourceId, EvaluationCtx context) {
return new ResourceFinderResult();
}
/**
* Tries to find the hierarchy of Resource Ids associated with the parent.
* If this module cannot handle the given identifier, then an empty result
* is returned, otherwise the result will always contain at least the
* parent Resource Id, either as a successfuly resolved Resource Id or an
* error case, but never both.
*
* @param parentResourceId the parent resource identifier
* @param context the representation of the request data
*
* @return the result of finding descendant resources
*/
public ResourceFinderResult findHierarchicyResources(
AttributeValue parentResourceId, EvaluationCtx context) {
return new ResourceFinderResult();
}
}