com.hp.hpl.jena.sparql.engine.main
Class StageBuilder
java.lang.Object
com.hp.hpl.jena.sparql.engine.main.StageBuilder
public class StageBuilder
- extends Object
The stage builder (there is only one) is a library that encapsulates
evaluation of a basic graph pattern (BGP). Matching BGPs is an extension
point of SPARQL; different entailment regimes plug in at this point.
They are also an extension point in ARQ to connect to any datasource,
the most common case being connectinbg to a Jena graph.
The StageBuilder finds the registered StageGenerator, and calls it to
evaluate a basic graph pattern that has any bound variables
replaced by their value (in effect, an index join).
Extension happens by registering a different StageGenerator in
the context object for the execution. Setting the StageGenerator
in the global context (ARQ
) makes it available
to all query execution created after the point of setting.
Helper static methods for setting the stage generator are provided.
StageBuilder
public StageBuilder()
execute
public static QueryIterator execute(BasicPattern pattern,
QueryIterator input,
ExecutionContext execCxt)
init
public static void init()
setGenerator
public static void setGenerator(Context context,
StageGenerator builder)
getGenerator
public static StageGenerator getGenerator(Context context)
getGenerator
public static StageGenerator getGenerator()
standardGenerator
public static StageGenerator standardGenerator()
Licenced under the Apache License, Version 2.0