org.openrdf.sesame.sailimpl.rdbms
Class RdbmsPathExpression

java.lang.Object
  org.openrdf.sesame.sailimpl.rdbms.RdbmsPathExpression

All Implemented Interfaces:

PathExpression

public class RdbmsPathExpression

extends Object

implements PathExpression

Version:

$Revision: 1.5.4.2 $

Author:

Arjohn Kampman

Constructor Summary

RdbmsPathExpression(RdfSource creator, RDBMS rdbms, List varList, String sqlQuery)
Constructor.

Method Summary

void	clear() Clears any state information in this path expression.
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.

Methods inherited from class java.lang.Object

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

Constructor Detail

RdbmsPathExpression

public RdbmsPathExpression(RdfSource creator,
                           RDBMS rdbms,
                           List varList,
                           String sqlQuery)

Constructor.

Parameters:

creator - The object to supply as 'creator' to created IdValues.

rdbms - An object representing the database to query.

varList - List of variables that need to be instantiated.

sqlQuery - SQL query to use to instantiate the variables.

Method Detail

initialize

public void initialize(RdfSource rdfSource)

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

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.