/*
* @(#)BasicPolicyFinderModule.java
*
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package com.sun.xacml.support.finder;
import com.sun.xacml.AbstractPolicy;
import com.sun.xacml.EvaluationCtx;
import com.sun.xacml.PolicyMetaData;
import com.sun.xacml.VersionConstraints;
import com.sun.xacml.combine.PolicyCombiningAlgorithm;
import com.sun.xacml.finder.PolicyFinder;
import com.sun.xacml.finder.PolicyFinderModule;
import com.sun.xacml.finder.PolicyFinderResult;
import java.net.URI;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* This is a basic implementation of <code>PolicyFinderModule</code> that
* accepts already created <code>AbstractPolicy</code>s and supports
* finding by context and reference. All policies are held forever once
* added to this module, and cannot be refreshed or removed. New policies
* may be added at any point. You may optionally specify a combining
* algorithm to use when more than one applicable policy is found, and then
* a new PolicySet is wrapped around the policies using this algorithm. If
* no combining algorithm is provided, then an error is returned if more
* than one policy matches.
* <p>
* This module is provided as an example, but is still fully functional, and
* should be useful for many simple applications. This is provided in the
* <code>support</code> package rather than the core codebase because it
* implements non-standard behavior.
*
* @since 2.0
* @author Seth Proctor
*/
public class BasicPolicyFinderModule extends PolicyFinderModule
{
// the collections used to handle both kinds of policies
private PolicyCollection ctxPolicies;
private PolicyCollection refPolicies;
// the policy identifier for any policy sets we dynamically create
private static final String POLICY_ID =
"urn:com:sun:xacml:support:finder:dynamic-policy-set";
private static URI policyId = null;
// the logger we'll use for all messages
private static final Logger logger =
Logger.getLogger(BasicPolicyFinderModule.class.getName());
static {
try {
policyId = new URI(POLICY_ID);
} catch (Exception e) {
// this can't actually happen, but just in case...
if (logger.isLoggable(Level.SEVERE)) {
logger.log(Level.SEVERE, "couldn't assign default policy id");
}
}
}
/**
* Creates a <code>BasicPolicyFinderModule</code>.
*/
public BasicPolicyFinderModule() {
this.ctxPolicies = new PolicyCollection();
this.refPolicies = new PolicyCollection();
}
/**
* Creates a <code>BasicPolicyFinderModule</code> that can combine
* multiple applicable policies under a single, dynamic PolicySet.
*
* @param combiningAlg the algorithm to use in a new PolicySet when more
* than one policy applies
*/
public BasicPolicyFinderModule(PolicyCombiningAlgorithm combiningAlg) {
this.ctxPolicies = new PolicyCollection(combiningAlg, policyId);
this.refPolicies = new PolicyCollection(combiningAlg, policyId);
}
/**
* Adds a policy that will be available both by reference and by
* matching to a context. The policy's identifier is used for finding
* by reference. If a policy with the same identifier and version is
* already handled by this module, then the policy is not added.
*
* @param policy the policy to add
*
* @return true if the policy was added, false otherwise
*/
public synchronized boolean addPolicy(AbstractPolicy policy) {
if (this.ctxPolicies.addPolicy(policy)) {
return this.refPolicies.addPolicy(policy);
}
return false;
}
/**
* Adds a policy that will be available only by matching to a context.
* If a policy with the same identifier and version is already handled
* by this module, then the policy is not added.
*
* @param policy the policy to add
*
* @return true if the policy was added, false otherwise
*/
public synchronized boolean addPolicyNoRef(AbstractPolicy policy) {
return this.ctxPolicies.addPolicy(policy);
}
/**
* Adds a policy that will be available only by reference. The policy's
* identifier is used for finding by reference. If a policy with the
* same identifier and version is already handled by this module, then
* the policy is not added.
*
* @param policy the policy to add
*
* @return true if the policy was added, false otherwise
*/
public synchronized boolean addPolicyOnlyRef(AbstractPolicy policy) {
return this.refPolicies.addPolicy(policy);
}
/**
* Always returns <code>true</code> since this module does support
* finding policies based on context matching.
*
* @return true
*/
public boolean isRequestSupported() {
return true;
}
/**
* Always returns <code>true</code> since this module does support
* finding policies based on reference.
*
* @return true
*/
public boolean isIdReferenceSupported() {
return true;
}
/**
* Initialize this module. Typically this is called by
* <code>PolicyFinder</code> when a PDP is created.
*
* @param finder the <code>PolicyFinder</code> using this module
*/
public void init(PolicyFinder finder) {
// we don't need to do anything here
}
/**
* Finds a policy based on a request's context. If more than one policy
* matches, then this either returns an error or a new policy wrapping
* the multiple policies (depending on which constructor was used to
* construct this instance).
*
* @param context the representation of the request data
*
* @return the result of trying to find an applicable policy
*/
public PolicyFinderResult findPolicy(EvaluationCtx context) {
context.newEvent(this);
try {
AbstractPolicy policy = this.ctxPolicies.getPolicy(context);
if (policy == null) {
context.closeCurrentEvent();
return new PolicyFinderResult();
}
context.closeCurrentEvent(policy.getId().toString());
return new PolicyFinderResult(policy);
} catch (TopLevelPolicyException tlpe) {
context.closeCurrentEvent();
return new PolicyFinderResult(tlpe.getStatus());
}
}
/**
* Attempts to find a policy by reference, based on the provided
* parameters.
*
* @param idReference an identifier specifying some policy
* @param type type of reference (policy or policySet) as identified by
* the fields in <code>PolicyReference</code>
* @param constraints any optional constraints on the version of the
* referenced policy (this will never be null, but
* it may impose no constraints, and in fact will
* never impose constraints when used from a pre-2.0
* XACML policy)
* @param parentMetaData the meta-data from the parent policy, which
* provides XACML version, factories, etc.
*
* @return the result of looking for a matching policy
*/
public PolicyFinderResult findPolicy(URI idReference, int type,
VersionConstraints constraints,
PolicyMetaData parentMetaData) {
AbstractPolicy policy =
this.refPolicies.getPolicy(idReference.toString(), type,
constraints);
if (policy == null) {
return new PolicyFinderResult();
}
return new PolicyFinderResult(policy);
}
}