Package org.eclipse.rdf4j.rio.hdt

Class HDTParser

java.lang.Object

org.eclipse.rdf4j.rio.helpers.AbstractRDFParser

org.eclipse.rdf4j.rio.hdt.HDTParser

All Implemented Interfaces:

RDFParser

public class HDTParser
extends AbstractRDFParser

RDF parser for HDT v1.0 files. This parser is not thread-safe, therefore its public methods are synchronized.

Unfortunately the draft specification is not entirely clear and probably slightly out of date, since the open source reference implementation HDT-It seems to implement a slightly different version. This parser tries to be compatible with HDT-It 1.0.

The most important parts are the Dictionaries containing the actual values (S, P, O part of a triple), and the Triples containing the numeric references to construct the triples.

Since objects in one triple are often subjects in another triple, these "shared" parts are stored in a shared Dictionary, which may significantly reduce the file size.

File structure:

 +---------------------+
 | Global              |
 | Header              |
 | Dictionary (Shared) |
 | Dictionary (S)      |
 | Dictionary (P)      |
 | Dictionary (O)      |
 | Triples             |
 +---------------------+
 

Author:

Bart Hanssens

See Also:

• HDT draft (2015)
• W3C Member Submission (2011)

Field Summary

Fields inherited from class org.eclipse.rdf4j.rio.helpers.AbstractRDFParser

rdfHandler, valueFactory

Constructor Summary

Constructors

Constructor	Description
HDTParser()	Creates a new HDTParser that will use a SimpleValueFactory to create RDF model objects.
HDTParser(ValueFactory valueFactory)	Creates a new HDTParser that will use the supplied ValueFactory to create RDF model objects.

Method Summary

Modifier and Type	Method	Description
RDFFormat	getRDFFormat()	Gets the RDF format that this parser can parse.
Collection<RioSetting<?>>	getSupportedSettings()
void	parse(InputStream in, String baseURI)	Parses the data from the supplied InputStream, using the supplied baseURI to resolve any relative URI references.
void	parse(Reader reader, String baseURI)	Not supported, since HDT is a binary format.

Methods inherited from class org.eclipse.rdf4j.rio.helpers.AbstractRDFParser

clear, clearBNodeIDMap, createBNode, createBNode, createLiteral, createLiteral, createLiteral, createNode, createNode, createStatement, createStatement, createURI, getNamespace, getParseErrorListener, getParseLocationListener, getParserConfig, getRDFHandler, initializeNamespaceTableFromConfiguration, preserveBNodeIDs, reportError, reportError, reportError, reportError, reportError, reportFatalError, reportFatalError, reportFatalError, reportFatalError, reportFatalError, reportLocation, reportWarning, reportWarning, resolveURI, set, setBaseURI, setBaseURI, setNamespace, setParseErrorListener, setParseLocationListener, setParserConfig, setPreserveBNodeIDs, setRDFHandler, setValueFactory

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.rdf4j.rio.RDFParser

parse, parse

Constructor Details

HDTParser

public HDTParser()

Creates a new HDTParser that will use a SimpleValueFactory to create RDF model objects.

HDTParser

public HDTParser(ValueFactory valueFactory)

Creates a new HDTParser that will use the supplied ValueFactory to create RDF model objects.

Parameters:

valueFactory - A ValueFactory.

Method Details

getRDFFormat

public RDFFormat getRDFFormat()

Description copied from interface: RDFParser

Gets the RDF format that this parser can parse.

getSupportedSettings

public Collection<RioSetting<?>> getSupportedSettings()

Specified by:

getSupportedSettings in interface RDFParser

Overrides:

getSupportedSettings in class AbstractRDFParser

Returns:

A collection of RioSettings that are supported by this RDFParser.

parse

public void parse(InputStream in,
 String baseURI)
           throws IOException,
RDFParseException,
RDFHandlerException

Description copied from interface: RDFParser

Parses the data from the supplied InputStream, using the supplied baseURI to resolve any relative URI references.

Parameters:

in - The InputStream from which to read the data.

baseURI - The URI associated with the data in the InputStream. May be null. Parsers for syntax formats that do not support relative URIs will ignore this argument.

Note that if the data contains an embedded base URI, that embedded base URI will overrule the value supplied here (see RFC 3986 section 5.1 for details).

Throws:

IOException - If an I/O error occurred while data was read from the InputStream.

RDFParseException - If the parser has found an unrecoverable parse error.

RDFHandlerException - If the configured statement handler has encountered an unrecoverable error.

parse

public void parse(Reader reader,
 String baseURI)
           throws RDFParseException,
RDFHandlerException

Not supported, since HDT is a binary format.

Parameters:

reader - The Reader from which to read the data.

baseURI - The URI associated with the data in the InputStream. May be null. Parsers for syntax formats that do not support relative URIs will ignore this argument.

Note that if the data contains an embedded base URI, that embedded base URI will overrule the value supplied here (see RFC 3986 section 5.1 for details).

Throws:

RDFParseException - If the parser has found an unrecoverable parse error.

RDFHandlerException - If the configured statement handler has encountered an unrecoverable error.