org.drools.rule
Class LiteralConstraint

java.lang.Object
  org.drools.rule.LiteralConstraint

All Implemented Interfaces:

Externalizable, Serializable, Cloneable, IndexableConstraint, Acceptor, AcceptsReadAccessor, AlphaNodeFieldConstraint, Constraint, RuleComponent

public class LiteralConstraint
extends Object
implements AlphaNodeFieldConstraint, IndexableConstraint, AcceptsReadAccessor, Externalizable

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.drools.spi.Constraint

Constraint.ConstraintType

Constructor Summary

LiteralConstraint()

LiteralConstraint(InternalReadAccessor extractor, Evaluator evaluator, FieldValue field)

LiteralConstraint(InternalReadAccessor extractor, LiteralRestriction restriction)

Method Summary

LiteralConstraint	clone() Clones the constraint
ContextEntry	createContextEntry()
boolean	equals(Object object)
Evaluator	getEvaluator()
FieldValue	getField()
InternalReadAccessor	getFieldExtractor()
AbstractHashTable.FieldIndex	getFieldIndex()
Declaration[]	getRequiredDeclarations() Literal constraints cannot have required declarations, so always return an empty array.
Constraint.ConstraintType	getType() Returns the type of the constraint, either ALPHA, BETA or UNKNOWN
int	hashCode()
boolean	isAllowed(InternalFactHandle handle, InternalWorkingMemory workingMemory, ContextEntry ctx)
boolean	isIndexable()
boolean	isTemporal() Returns true in case this constraint is a temporal constraint
boolean	isUnification()
void	readExternal(ObjectInput in)
void	replaceDeclaration(Declaration oldDecl, Declaration newDecl) When a rule contains multiple logical branches, i.e., makes use of 'OR' CE, it is required to clone patterns and declarations for each logical branch.
void	setReadAccessor(InternalReadAccessor readAccessor)
String	toString()
void	writeExternal(ObjectOutput out)

Methods inherited from class java.lang.Object

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

Constructor Detail

LiteralConstraint

public LiteralConstraint()

LiteralConstraint

public LiteralConstraint(InternalReadAccessor extractor,
                         Evaluator evaluator,
                         FieldValue field)

LiteralConstraint

public LiteralConstraint(InternalReadAccessor extractor,
                         LiteralRestriction restriction)

Method Detail

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Throws:

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Throws:

IOException

setReadAccessor

public void setReadAccessor(InternalReadAccessor readAccessor)

Specified by:

setReadAccessor in interface AcceptsReadAccessor

getEvaluator

public Evaluator getEvaluator()

getField

public FieldValue getField()

Specified by:

getField in interface IndexableConstraint

getFieldExtractor

public InternalReadAccessor getFieldExtractor()

Specified by:

getFieldExtractor in interface IndexableConstraint

getRequiredDeclarations

public Declaration[] getRequiredDeclarations()

Literal constraints cannot have required declarations, so always return an empty array.

Specified by:

getRequiredDeclarations in interface Constraint

Returns:

Return an empty Declaration[]

replaceDeclaration

public void replaceDeclaration(Declaration oldDecl,
                               Declaration newDecl)

Description copied from interface: Constraint

When a rule contains multiple logical branches, i.e., makes use of 'OR' CE, it is required to clone patterns and declarations for each logical branch. Since this is done at ReteOO build type, when constraints were already created, eventually some constraints need to update their references to the declarations.

Specified by:

replaceDeclaration in interface Constraint

isAllowed

public boolean isAllowed(InternalFactHandle handle,
                         InternalWorkingMemory workingMemory,
                         ContextEntry ctx)

Specified by:

isAllowed in interface AlphaNodeFieldConstraint

toString

public String toString()

Overrides:

toString in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object object)

Overrides:

equals in class Object

clone

public LiteralConstraint clone()

Description copied from interface: Constraint

Clones the constraint

Specified by:

clone in interface Constraint

Overrides:

clone in class Object

Returns:

createContextEntry

public ContextEntry createContextEntry()

Specified by:

createContextEntry in interface AlphaNodeFieldConstraint

getType

public Constraint.ConstraintType getType()

Description copied from interface: Constraint

Returns the type of the constraint, either ALPHA, BETA or UNKNOWN

Specified by:

getType in interface Constraint

Returns:

isTemporal

public boolean isTemporal()

Description copied from interface: Constraint

Returns true in case this constraint is a temporal constraint

Specified by:

isTemporal in interface Constraint

Returns:

isUnification

public boolean isUnification()

Specified by:

isUnification in interface IndexableConstraint

isIndexable

public boolean isIndexable()

Specified by:

isIndexable in interface IndexableConstraint

getFieldIndex

public AbstractHashTable.FieldIndex getFieldIndex()

Specified by:

getFieldIndex in interface IndexableConstraint