Class SparqlQueryClient

A class for connecting to a remote SPARQL endpoint and making queries against it using the System.Net.Http library.

Inheritance

System.Object

SparqlQueryClient

Implements

ISparqlQueryClient

IConfigurationSerializable

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: VDS.RDF.Query

Assembly: dotNetRdf.dll

Syntax

public class SparqlQueryClient : ISparqlQueryClient, IConfigurationSerializable

Constructors

SparqlQueryClient(HttpClient, Uri)

Create a new SPARQL client.

Declaration

public SparqlQueryClient(HttpClient httpClient, Uri endpointUri)

Parameters

Type	Name	Description
System.Net.Http.HttpClient	httpClient	The underlying client to use for HTTP requests.
System.Uri	endpointUri	The URI of the SPARQL endpoint to connect to.

Properties

DefaultGraphs

Gets the Default Graph URIs for Queries made to the SPARQL Endpoint.

Declaration

public List<string> DefaultGraphs { get; }

Property Value

Type	Description
System.Collections.Generic.List<T><string>

EndpointUri

Gets the URI of the remote SPARQL endpoint.

Declaration

public Uri EndpointUri { get; }

Property Value

Type	Description
System.Uri

HttpMode

Get or set the mode used to determine the HTTP method to be used by the client.

Declaration

public HttpMode HttpMode { get; set; }

Property Value

Type	Description
HttpMode

Remarks

The default mode is Auto which uses a GET unless the SPARQL query is too long or contains characters that cannot be encoded as an HTTP query string, in which case POST is used.

NamedGraphs

Gets the List of Named Graphs used in requests.

Declaration

public List<string> NamedGraphs { get; }

Property Value

Type	Description
System.Collections.Generic.List<T><string>

RdfAcceptHeader

Gets/Sets the Accept Header sent with CONSTRUCT/DESCRIBE queries.

Declaration

public string RdfAcceptHeader { get; set; }

Property Value

Type	Description
string

Remarks

Can be used to workaround buggy endpoints which don't like the broad Accept Header that dotNetRDF sends by default. If not set or explicitly set to null the library uses the default header generated by HttpAcceptHeader.

ResultsAcceptHeader

Gets/Sets the Accept Header sent with ASK/SELECT queries.

Declaration

public string ResultsAcceptHeader { get; set; }

Property Value

Type	Description
string

Remarks

Can be used to workaround buggy endpoints which don't like the broad Accept Header that dotNetRDF sends by default. If not set or explicitly set to null the library uses the default header generated by HttpSparqlAcceptHeader.

Methods

QueryAsync(string, IRdfHandler, ISparqlResultsHandler, CancellationToken)

Execute a SPARQL query.

Declaration

public Task QueryAsync(string sparqlQuery, IRdfHandler graphHandler, ISparqlResultsHandler resultsHandler, CancellationToken cancellationToken)

Parameters

Type	Name	Description
string	sparqlQuery	The query to be executed.
IRdfHandler	graphHandler	The handler to use when paring graph results from a CONSTRUCT or DESCRIBE query.
ISparqlResultsHandler	resultsHandler	The handler to sue when parsing SPARQL results sets from a SELECT or ASK query.
System.Threading.CancellationToken	cancellationToken	A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Type	Description
System.Threading.Tasks.Task

QueryInternal(string, string, CancellationToken)

Internal method which builds and executes the query as a GET or POST as appropriate.

Declaration

protected Task<HttpResponseMessage> QueryInternal(string sparqlQuery, string acceptHeader, CancellationToken cancellationToken)

Parameters

Type	Name	Description
string	sparqlQuery	The SPARQL query string.
string	acceptHeader	The value to insert into the Accept header of the outgoing HTTP request.
System.Threading.CancellationToken	cancellationToken	A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Type	Description
System.Threading.Tasks.Task<TResult><System.Net.Http.HttpResponseMessage>

QueryWithResultGraphAsync(string, CancellationToken)

Execute a SPARQL query that is intended to return an RDF Graph.

Declaration

public Task<IGraph> QueryWithResultGraphAsync(string sparqlQuery, CancellationToken cancellationToken)

Parameters

Type	Name	Description
string	sparqlQuery	The query to be executed.
System.Threading.CancellationToken	cancellationToken	A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Type	Description
System.Threading.Tasks.Task<TResult><IGraph>	An RDF Graph.

Remarks

This method should be used when processing SPARQL CONSTRUCT or DESCRIBE queries.

QueryWithResultGraphAsync(string, IRdfHandler, CancellationToken)

Execute a SPARQL query that is intended to return an RDF Graph.

Declaration

public Task QueryWithResultGraphAsync(string sparqlQuery, IRdfHandler handler, CancellationToken cancellationToken)

Parameters

Type	Name	Description
string	sparqlQuery	The query to be executed.
IRdfHandler	handler	The handler to use when parsing the graph data returned by the server.
System.Threading.CancellationToken	cancellationToken	A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Type	Description
System.Threading.Tasks.Task	An RDF Graph.

Remarks

This method should be used when processing SPARQL CONSTRUCT or DESCRIBE queries.

QueryWithResultGraphAsync(string, IRdfHandler)

Execute a SPARQL query that is intended to return an RDF Graph.

Declaration

public Task QueryWithResultGraphAsync(string sparqlQuery, IRdfHandler handler)

Parameters

Type	Name	Description
string	sparqlQuery	The query to be executed.
IRdfHandler	handler	The handler to use when parsing the graph data returned by the server.

Returns

Type	Description
System.Threading.Tasks.Task	An RDF Graph.

Remarks

This method should be used when processing SPARQL CONSTRUCT or DESCRIBE queries.

QueryWithResultGraphAsync(string)

Execute a SPARQL query that is intended to return an RDF Graph.

Declaration

public Task<IGraph> QueryWithResultGraphAsync(string sparqlQuery)

Parameters

Type	Name	Description
string	sparqlQuery	The query to be executed.

Returns

Type	Description
System.Threading.Tasks.Task<TResult><IGraph>	An RDF Graph.

Remarks

This method should be used when processing SPARQL CONSTRUCT or DESCRIBE queries.

QueryWithResultSetAsync(string, CancellationToken)

Execute a SPARQL query that is intended to return a SPARQL results set.

Declaration

public Task<SparqlResultSet> QueryWithResultSetAsync(string sparqlQuery, CancellationToken cancellationToken)

Parameters

Type	Name	Description
string	sparqlQuery	The query to be executed.
System.Threading.CancellationToken	cancellationToken	A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Type	Description
System.Threading.Tasks.Task<TResult><SparqlResultSet>	The query results.

Remarks

This method should be used when processing SPARQL SELECT or ASK queries.

QueryWithResultSetAsync(string, ISparqlResultsHandler, CancellationToken)

Execute a SPARQL query that is intended to return a SPARQL results set.

Declaration

public Task QueryWithResultSetAsync(string sparqlQuery, ISparqlResultsHandler resultsHandler, CancellationToken cancellationToken)

Parameters

Type	Name	Description
string	sparqlQuery	The query to be executed.
ISparqlResultsHandler	resultsHandler	The handler to use when parsing the results returned by the server.
System.Threading.CancellationToken	cancellationToken	A cancellation token that can be used by other objects or threads to receive notice of cancellation.

Returns

Type	Description
System.Threading.Tasks.Task	The query results.

Remarks

This method should be used when processing SPARQL SELECT or ASK queries.

QueryWithResultSetAsync(string, ISparqlResultsHandler)

Execute a SPARQL query that is intended to return a SPARQL results set.

Declaration

public Task QueryWithResultSetAsync(string sparqlQuery, ISparqlResultsHandler resultsHandler)

Parameters

Type	Name	Description
string	sparqlQuery	The query to be executed.
ISparqlResultsHandler	resultsHandler	The handler to use when parsing the results returned by the server.

Returns

Type	Description
System.Threading.Tasks.Task	The query results.

Remarks

This method should be used when processing SPARQL SELECT or ASK queries.

QueryWithResultSetAsync(string)

Execute a SPARQL query that is intended to return a SPARQL results set.

Declaration

public Task<SparqlResultSet> QueryWithResultSetAsync(string sparqlQuery)

Parameters

Type	Name	Description
string	sparqlQuery	The query to be executed.

Returns

Type	Description
System.Threading.Tasks.Task<TResult><SparqlResultSet>	The query results.

Remarks

This method should be used when processing SPARQL SELECT or ASK queries.

SerializeConfiguration(ConfigurationSerializationContext)

Serializes the Endpoint's Configuration.

Declaration

public void SerializeConfiguration(ConfigurationSerializationContext context)

Parameters

Type	Name	Description
ConfigurationSerializationContext	context	Configuration Serialization Context.

Implements

ISparqlQueryClient

IConfigurationSerializable

Extension Methods

Extensions.ToSafeString(object)

Extensions.AsEnumerable<T>(T)