eu.gambas.system.query.generic

Class AbstractQueryProcessor

java.lang.Object

eu.gambas.system.query.generic.AbstractQueryProcessor

All Implemented Interfaces:

QueryProcessor

Direct Known Subclasses:

QueryProcessorForJ2SE

public abstract class AbstractQueryProcessor
extends java.lang.Object
implements QueryProcessor

An abstract platform independent query processor implementation that uses a distributed query processor to execute onetime queries.

Author:

Gregor Schiele

Constructor Summary

Constructors

Constructor and Description
AbstractQueryProcessor(DistributedQueryProcessor oqp)

Method Summary

Methods

Modifier and Type	Method and Description
CompactSparqlQueryResults	executeOnetimeSparqlQuery(CallerContext context, java.lang.String query) Execute a (possibly distributed and/or remote) onetime SPARQL query on data in one or more semantic data stores.

Methods inherited from class java.lang.Object

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

Methods inherited from interface eu.gambas.sdk.spi.lod.QueryProcessor

executeContinuousSparqlQuery

Constructor Detail

AbstractQueryProcessor

public AbstractQueryProcessor(DistributedQueryProcessor oqp)

Method Detail

executeOnetimeSparqlQuery

public CompactSparqlQueryResults executeOnetimeSparqlQuery(CallerContext context,
                                                  java.lang.String query)
                                                    throws QueryExecutionException

Description copied from interface: QueryProcessor

Execute a (possibly distributed and/or remote) onetime SPARQL query on data in one or more semantic data stores. This query may contain remote subquery parts using the SERVICE keyword of SPARQL 1.1. Note that GAMBAS so far does not support unbound remote endpoints, e.g. something like SERVICE ?var. Instead, the URI given with SERVICE identifies a GAMBAS user (i.e. the URI used to store this user in a semantic data store). Each identified user must be stored in the local data store to allow the query processor to automatically derive the right endpoint for each user and contact it remotely.

Specified by:

executeOnetimeSparqlQuery in interface QueryProcessor

Parameters:

context - Additional information about the caller, e.g. its identity - needed for privacy!

query - The actual SPARQL query.

Returns:

The result set of the query encoded with JSON.

Throws:

QueryExecutionException