org.openrdf.sesame.sail.query
Class TriplePattern

java.lang.Object
  org.openrdf.sesame.sail.query.TriplePattern

All Implemented Interfaces:

PathExpression

Direct Known Subclasses:

DirectSubClassOf, DirectSubPropertyOf, DirectType

public class TriplePattern

extends Object

implements PathExpression

Author:

Arjohn Kampman

Constructor Summary

TriplePattern(Var subjectVar, Var predicateVar, Var objectVar)

Method Summary

void	clear() Clears any state information in this path expression.
Var	getObjectVar()
Var	getPredicateVar()
Var	getSubjectVar()
void	getVariables(Collection variables) Gets all variables that are used in this PathExpression.
void	initialize(RdfSource rdfSource) Initializes the PathExpression.
boolean	selectNext(RdfSource rdfSource) Selects the next path matching this path expression.
String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

TriplePattern

public TriplePattern(Var subjectVar,
                     Var predicateVar,
                     Var objectVar)

Method Detail

getSubjectVar

public Var getSubjectVar()

getPredicateVar

public Var getPredicateVar()

getObjectVar

public Var getObjectVar()

initialize

public void initialize(RdfSource rdfSource)
                throws SailQueryException

Description copied from interface: PathExpression

Initializes the PathExpression. After a call to this method, the path expression should be able to select all matching path expressions when selectNext is called.

Specified by:

initialize in interface PathExpression

Throws:

SailQueryException

selectNext

public boolean selectNext(RdfSource rdfSource)

Description copied from interface: PathExpression

Selects the next path matching this path expression. Any variables in this path expression should be instantiated after a successful call to this method. When no more matching paths could be found, any bound variables should be uninstantiated.

Specified by:

selectNext in interface PathExpression

Returns:

true if a next path has been found, false if no more paths could be found.

clear

public void clear()

Description copied from interface: PathExpression

Clears any state information in this path expression. After a call to this method, calls to selectNext should not yield any new results.

Specified by:

clear in interface PathExpression

getVariables

public void getVariables(Collection variables)

Description copied from interface: PathExpression

Gets all variables that are used in this PathExpression.

Specified by:

getVariables in interface PathExpression

Parameters:

variables - A Collection to add the Var objects to.

toString

public String toString()