Package org.apache.jena.sparql.engine

Interface QueryEngineFactory

All Known Implementing Classes:

QueryEngineFactoryWrapper

public interface QueryEngineFactory

A QueryEngineFactory builds query Plans via create(Query, DatasetGraph, Binding, Context) or create(Op, DatasetGraph, Binding, Context). A Plan has a query iterator for the results of executing the Op, a SPARQL algebra expression with local extensions.

* A QueryEngineFactory is registered with the QueryEngineRegistry.

* When determining which factory to use, the querye execution process calls accept(Query, DatasetGraph, Context) or accept(Op, DatasetGraph, Context) to determine whether the particular type of query engine produced by this factory accepts the particular request.

A QueryEngineFactory can be registered for use with QueryEngineRegistry.addFactory(QueryEngineFactory) and unregistered with QueryEngineRegistry.removeFactory(QueryEngineFactory).

Method Summary

Modifier and Type	Method	Description
boolean	accept(Query query, DatasetGraph dataset, Context context)	Detect appropriate requests for a particular query engine for a particular graph type.
boolean	accept(Op op, DatasetGraph dataset, Context context)	Detect appropriate requests for a particular query engine for a particular graph type.
Plan	create(Query query, DatasetGraph dataset, Binding inputBinding, Context context)	Call to create a Plan : the companion accept(org.apache.jena.query.Query, org.apache.jena.sparql.core.DatasetGraph, org.apache.jena.sparql.util.Context) will have returned true.
Plan	create(Op op, DatasetGraph dataset, Binding inputBinding, Context context)	Call to create a Plan : the companion accept(org.apache.jena.query.Query, org.apache.jena.sparql.core.DatasetGraph, org.apache.jena.sparql.util.Context) will have returned true.

Method Detail

accept

boolean accept(Query query,
               DatasetGraph dataset,
               Context context)

Detect appropriate requests for a particular query engine for a particular graph type.

Parameters:

query - a Query to be executed

dataset - the DatasetGraph over which the query is to be executed

context - the Context in which the query is to be executed

Returns:

whether the kind of query engine produced by this factory can handle this task

create

Plan create(Query query,
            DatasetGraph dataset,
            Binding inputBinding,
            Context context)

Call to create a Plan : the companion accept(org.apache.jena.query.Query, org.apache.jena.sparql.core.DatasetGraph, org.apache.jena.sparql.util.Context) will have returned true.

Parameters:

query -

dataset -

inputBinding -

context -

accept

boolean accept(Op op,
               DatasetGraph dataset,
               Context context)

Detect appropriate requests for a particular query engine for a particular graph type.

Parameters:

op - an Op to be executed

dataset - the DatasetGraph over which the operation is to be executed

context - the Context in which the operation is to be executed

Returns:

whether the kind of query engine produced by this factory can handle this task

create

Plan create(Op op,
            DatasetGraph dataset,
            Binding inputBinding,
            Context context)

Call to create a Plan : the companion accept(org.apache.jena.query.Query, org.apache.jena.sparql.core.DatasetGraph, org.apache.jena.sparql.util.Context) will have returned true.

Parameters:

op -

dataset -

inputBinding -

context -