Package se.liu.ida.hefquin.engine.wrappers.graphql.impl

Class SPARQL2GraphQLTranslatorImpl

java.lang.Object

se.liu.ida.hefquin.engine.wrappers.graphql.impl.SPARQL2GraphQLTranslatorImpl

All Implemented Interfaces:

SPARQL2GraphQLTranslator

public class SPARQL2GraphQLTranslatorImpl
extends Object
implements SPARQL2GraphQLTranslator

Constructor Summary

Constructors

Constructor	Description
SPARQL2GraphQLTranslatorImpl()

Method Summary

Modifier and Type	Method	Description
protected Map<TriplePattern,StarPattern>	createConnectors(Map<org.apache.jena.graph.Node,StarPattern> indexedStarPatterns)	Creates a connector map using @param indexedStarPatterns
protected Map<org.apache.jena.graph.Node,StarPattern>	decomposeIntoStarPatterns(BGP bgp)	Decomposes the given BGP into its subject-based star patterns and returns the resulting star patterns indexed by their respective subject nodes.
protected Set<GraphQLQueryRootForStarPattern>	determineRootStarPatterns(Collection<StarPattern> sps, Map<TriplePattern,StarPattern> connectors, GraphQL2RDFConfiguration cfg, GraphQLSchema schema)	Returns the star patterns from the given collection that will be used for creating entry points in the GraphQL query to be generated.
protected GraphQLQuery	generateQueryData(SPARQL2GraphQLHelper helper, Set<GraphQLQueryRootForStarPattern> queryRoots)	Generates a GraphQL query from provided @param indexedStarPatterns,connectors,withoutConnnectors
GraphQLQuery	translateBGP(BGP bgp, GraphQL2RDFConfiguration config, GraphQLSchema schema)	Translates @param bgp into a GraphQL query using information from @param config and @param endpoint

Methods inherited from class java.lang.Object

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

Constructor Details

SPARQL2GraphQLTranslatorImpl

public SPARQL2GraphQLTranslatorImpl()

Method Details

translateBGP

public GraphQLQuery translateBGP(BGP bgp,
 GraphQL2RDFConfiguration config,
 GraphQLSchema schema)
                          throws QueryTranslatingException

Description copied from interface: SPARQL2GraphQLTranslator

Translates @param bgp into a GraphQL query using information from @param config and @param endpoint

Specified by:

translateBGP in interface SPARQL2GraphQLTranslator

Throws:

QueryTranslatingException - if there was some problem translating the query.

decomposeIntoStarPatterns

protected Map<org.apache.jena.graph.Node,StarPattern> decomposeIntoStarPatterns(BGP bgp)

Decomposes the given BGP into its subject-based star patterns and returns the resulting star patterns indexed by their respective subject nodes.

createConnectors

protected Map<TriplePattern,StarPattern> createConnectors(Map<org.apache.jena.graph.Node,StarPattern> indexedStarPatterns)

Creates a connector map using @param indexedStarPatterns

determineRootStarPatterns

protected Set<GraphQLQueryRootForStarPattern> determineRootStarPatterns(Collection<StarPattern> sps,
 Map<TriplePattern,StarPattern> connectors,
 GraphQL2RDFConfiguration cfg,
 GraphQLSchema schema)

Returns the star patterns from the given collection that will be used for creating entry points in the GraphQL query to be generated. To this end, the given collection of star patterns is first filtered to ignore every star pattern that has an incoming connector. Thereafter, for each of the remaining star patterns (i.e., the ones that do not have an incoming connector), the corresponding GraphQL object type is determined and associated with the star pattern before adding it to the output set. Finally, the output set is returned only if it was possible to determine a corresponding GraphQL object type for all of the star patterns therein. If there is at least one such star pattern for which it was not possible, then this function returns null.

generateQueryData

protected GraphQLQuery generateQueryData(SPARQL2GraphQLHelper helper,
 Set<GraphQLQueryRootForStarPattern> queryRoots)
                                  throws QueryTranslatingException

Generates a GraphQL query from provided @param indexedStarPatterns,connectors,withoutConnnectors

Throws:

QueryTranslatingException - if no valid entrypoint for a star pattern was found.