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Unfortunately the draft specification is not entirely clear and probably slightly out of date, since the open source reference implementation HDT-It seems to implement a slightly different version.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:

  • 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 IOException, 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:
      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.