org.eclipse.rdf4j.query.resultio

Interface QueryResultWriter

All Superinterfaces:

QueryResultHandler

All Known Subinterfaces:

BooleanQueryResultWriter, TupleQueryResultWriter

All Known Implementing Classes:

AbstractQueryResultWriter, BinaryQueryResultWriter, BooleanTextWriter, ConsoleQueryResultWriter, QueryResultWriterBase, SPARQLBooleanJSONWriter, SPARQLBooleanXMLWriter, SPARQLResultsCSVWriter, SPARQLResultsJSONWriter, SPARQLResultsTSVWriter, SPARQLResultsXMLWriter, SPARQLStarResultsJSONWriter, SPARQLStarResultsTSVWriter

public interface QueryResultWriter
extends QueryResultHandler

The base interface for writers of query results sets and boolean results.

Author:

Peter Ansell

Method Summary

Modifier and Type	Method and Description
void	endHeader() Indicates the end of the header.
default Optional<OutputStream>	getOutputStream() Gets the OutputStream this writer writes to, if it uses one.
QueryResultFormat	getQueryResultFormat() Gets the query result format that this writer uses.
Collection<RioSetting<?>>	getSupportedSettings()
WriterConfig	getWriterConfig() Retrieves the current writer configuration as a single object.
void	handleNamespace(String prefix, String uri) Handles a namespace prefix declaration.
void	handleStylesheet(String stylesheetUrl) Handles a stylesheet URL.
void	setWriterConfig(WriterConfig config) Sets all supplied writer configuration options.
void	startDocument() Indicates the start of the document.
void	startHeader() Indicates the start of the header.

Methods inherited from interface org.eclipse.rdf4j.query.QueryResultHandler

endQueryResult, handleBoolean, handleLinks, handleSolution, startQueryResult

Method Detail

getQueryResultFormat

QueryResultFormat getQueryResultFormat()

Gets the query result format that this writer uses.

getOutputStream

@InternalUseOnly
 @Experimental
default Optional<OutputStream> getOutputStream()

Gets the OutputStream this writer writes to, if it uses one.

Returns:

an optional OutputStream

Since:

3.2.0

handleNamespace

void handleNamespace(String prefix,
                     String uri)
              throws QueryResultHandlerException

Handles a namespace prefix declaration. If this is called, it should be called before startDocument() to ensure that it has a document wide effect.

NOTE: If the format does not support namespaces, it must silently ignore calls to this method.

Parameters:

prefix - The prefix to use for the namespace

uri - The full URI that is to be represented by the prefix.

Throws:

QueryResultHandlerException

startDocument

void startDocument()
            throws QueryResultHandlerException

Indicates the start of the document.

Throws:

QueryResultHandlerException - If there was an error starting the writing of the results.

handleStylesheet

void handleStylesheet(String stylesheetUrl)
               throws QueryResultHandlerException

Handles a stylesheet URL. If this is called, it must be called after startDocument() and before startHeader().

NOTE: If the format does not support stylesheets, it must silently ignore calls to this method.

Parameters:

stylesheetUrl - The URL of the stylesheet to be used to style the results.

Throws:

QueryResultHandlerException - If there was an error handling the stylesheet. This error is not thrown in cases where stylesheets are not supported.

startHeader

void startHeader()
          throws QueryResultHandlerException

Indicates the start of the header.

Throws:

QueryResultHandlerException - If there was an error writing the start of the header.

See Also:

SPARQL Query Results XML Format documentation for head element.

endHeader

void endHeader()
        throws QueryResultHandlerException

Indicates the end of the header. This must be called after startHeader() and before any calls to QueryResultHandler.handleSolution(org.eclipse.rdf4j.query.BindingSet).

Throws:

QueryResultHandlerException - If there was an error writing the end of the header.

setWriterConfig

void setWriterConfig(WriterConfig config)

Sets all supplied writer configuration options.

Parameters:

config - a writer configuration object.

getWriterConfig

WriterConfig getWriterConfig()

Retrieves the current writer configuration as a single object.

Returns:

a writer configuration object representing the current configuration of the writer.

getSupportedSettings

Collection<RioSetting<?>> getSupportedSettings()

Returns:

A collection of RioSettings that are supported by this QueryResultWriter.