Package org.ow2.authzforce.core.pdp.api.expression

Class GenericAttributeProviderBasedAttributeDesignatorExpression<AV extends AttributeValue>

java.lang.Object

org.ow2.authzforce.core.pdp.api.expression.GenericAttributeProviderBasedAttributeDesignatorExpression<AV>

Type Parameters:

AV - AttributeDesignator evaluation result value's primitive datatype

All Implemented Interfaces:

AttributeDesignatorExpression<AV>, Expression<Bag<AV>>

public final class GenericAttributeProviderBasedAttributeDesignatorExpression<AV extends AttributeValue>
extends Object
implements AttributeDesignatorExpression<AV>

AttributeDesignator evaluator initialized with and using an NamedAttributeProvider to retrieve the attribute value

Version:

$Id: $

Constructor Summary

Constructors

Constructor	Description
GenericAttributeProviderBasedAttributeDesignatorExpression(AttributeFqn attributeName, boolean mustBePresent, BagDatatype<AV> resultDatatype, SingleNamedAttributeProvider<AV> attributeProvider)	Return an instance of an AttributeDesignator based on an AttributeDesignatorType

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object obj)	Equal iff the Attribute Category/Issuer/Id are equal
Bag<AV>	evaluate(EvaluationContext individualDecisionContext, Optional<EvaluationContext> mdpContext)	Evaluates the expression using the given context.
AttributeFqn	getAttributeFQN()	Get Attribute Category/Issuer/Id
Datatype<Bag<AV>>	getReturnType()	Gets the expected return type of the expression if evaluated.
Optional<Bag<AV>>	getValue()	Get the constant value of this expression if it has a constant value, i.e.
int	hashCode()
boolean	isNonEmptyBagRequired()	Indicates whether the attribute's presence is required, i.e.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

GenericAttributeProviderBasedAttributeDesignatorExpression

public GenericAttributeProviderBasedAttributeDesignatorExpression(AttributeFqn attributeName,
                                                                  boolean mustBePresent,
                                                                  BagDatatype<AV> resultDatatype,
                                                                  SingleNamedAttributeProvider<AV> attributeProvider)

Return an instance of an AttributeDesignator based on an AttributeDesignatorType

Parameters:

attributeName - the AttributeDesignatorType we want to convert

mustBePresent - AttributeDesignator's MustBePresent

resultDatatype - expected datatype of the result attribute value ( AV is the expected type of every element in the bag)

attributeProvider - Attribute Provider responsible for finding the values of the attribute designated by attributeName in a given evaluation context at runtime. When evaluate(EvaluationContext, Optional) is called, all AttributeProvider(s) are called in the list order

Throws:

IllegalArgumentException - if attrDesignator.getCategory() == null || attrDesignator.getAttributeId() == null

Method Detail

getValue

public Optional<Bag<AV>> getValue()

Get the constant value of this expression if it has a constant value, i.e. independent of the evaluation context (e.g. AttributeValue, VariableReference to AttributeValue...). This is equivalent to call Expression.evaluate(EvaluationContext, Optional) with individualDecisionContext == null and mdpContext == Optional.empty(). This enables expression consumers to do optimizations, e.g. functions may pre-compile/pre-evaluate parts of their inputs knowing some are constant values.

Specified by:

getValue in interface Expression<AV extends AttributeValue>

Returns:

the constant value iff the expression has a static/fixed/constant value, else no present value. NB: Null is not considered/possible as a constant value for expressions.

getAttributeFQN

public AttributeFqn getAttributeFQN()

Description copied from interface: AttributeDesignatorExpression

Get Attribute Category/Issuer/Id

Specified by:

getAttributeFQN in interface AttributeDesignatorExpression<AV extends AttributeValue>

Returns:

attribute GUID (category, issuer, ID)

isNonEmptyBagRequired

public boolean isNonEmptyBagRequired()

Description copied from interface: AttributeDesignatorExpression

Indicates whether the attribute's presence is required, i.e. it must have at least one value in this context (non-empty bag). Equivalent of XACML MustBePresent flag.

Specified by:

isNonEmptyBagRequired in interface AttributeDesignatorExpression<AV extends AttributeValue>

Returns:

true iff the resulting bag must be non-empty, i.e. there must be at least one value for this attribute in the context

evaluate

public Bag<AV> evaluate(EvaluationContext individualDecisionContext,
                        Optional<EvaluationContext> mdpContext)
                 throws IndeterminateEvaluationException

Description copied from interface: Expression

Evaluates the expression using the given context.

Specified by:

evaluate in interface Expression<AV extends AttributeValue>

Parameters:

individualDecisionContext - Individual Decision)request context

mdpContext - the context of the Multiple Decision request that the individualDecisionContext belongs to if the Multiple Decision Profile is used.

Returns:

the result of evaluation that may be a single value T (e.g. function result, AttributeValue, Condition, Match...) or bag of values (e.g. AttributeDesignator, AttributeSelector)

Throws:

IndeterminateEvaluationException - if evaluation is "Indeterminate" (see XACML core specification)

getReturnType

public Datatype<Bag<AV>> getReturnType()

Gets the expected return type of the expression if evaluated.

Specified by:

getReturnType in interface Expression<AV extends AttributeValue>

Returns:

expression evaluation's return type

toString

public String toString()

Overrides:

toString in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Equal iff the Attribute Category/Issuer/Id are equal

Overrides:

equals in class Object