org.wso2.balana.finder

Class PolicyFinder

java.lang.Object

org.wso2.balana.finder.PolicyFinder

public class PolicyFinder
extends Object

This class is used by the PDP to find all policies used in evaluation. A PDP is given a pre-configured PolicyFinder on construction. The PolicyFinder provides the functionality both to find policies based on a request (ie, retrieve policies and match against the target) and based on an idReference (as can be included in a PolicySet).

While this class is typically used by the PDP, it is intentionally designed to support stand-alone use, so it could be the base for a distributed service, or for some application that needs just this functionality. There is nothing in the PolicyFinder Note that it is an error to have more than one top-level policy (as explained in the OnlyOneApplicable combining algorithm), so any module that is added to this finder will be evaluated each time a policy is requested. This means that you should think carefully about how many modules you include, and how they can cache policy data.

Since:

1.0

Author:

Seth Proctor

Constructor Summary

Constructors

Constructor and Description
PolicyFinder() Default constructor that creates a PDPConfig from components.

Method Summary

Modifier and Type	Method and Description
PolicyFinderResult	findPolicy(EvaluationCtx context) Finds a policy based on a request's context.
PolicyFinderResult	findPolicy(URI idReference, int type, VersionConstraints constraints, PolicyMetaData parentMetaData) Finds a policy based on an id reference.
Set	getModules() Returns the unordered Set of PolicyFinderModules used by this class to find policies.
void	init() Initializes all modules in this finder.
void	setModules(Set modules) Sets the unordered Set of PolicyFinderModules used by this class to find policies.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PolicyFinder

public PolicyFinder()

Default constructor that creates a PDPConfig from components.

Method Detail

getModules

public Set getModules()

Returns the unordered Set of PolicyFinderModules used by this class to find policies.

Returns:

a Set of PolicyFinderModules

setModules

public void setModules(Set modules)

Sets the unordered Set of PolicyFinderModules used by this class to find policies.

Parameters:

modules - a Set of PolicyFinderModules

init

public void init()

Initializes all modules in this finder.

findPolicy

public PolicyFinderResult findPolicy(EvaluationCtx context)

Finds a policy based on a request's context. This may involve using the request data as indexing data to lookup a policy. This will always do a Target match to make sure that the given policy applies. If more than one applicable policy is found, this will return an error.

Parameters:

context - the representation of the request data

Returns:

the result of trying to find an applicable policy

findPolicy

public PolicyFinderResult findPolicy(URI idReference,
                                     int type,
                                     VersionConstraints constraints,
                                     PolicyMetaData parentMetaData)
                              throws IllegalArgumentException

Finds a policy based on an id reference. This may involve using the reference as indexing data to lookup a policy. This will always do a Target match to make sure that the given policy applies. If more than one applicable policy is found, this will return an error.

Parameters:

idReference - the identifier used to resolve a policy

type - type of reference (policy or policySet) as identified by the fields in PolicyReference

constraints - any optional constraints on the version of the referenced policy

parentMetaData - the meta-data from the parent policy, which provides XACML version, factories, etc.

Returns:

the result of trying to find an applicable policy

Throws:

IllegalArgumentException - if type is invalid