org.eclipse.rdf4j.rio

## Interface DatatypeHandler

- All Known Implementing Classes:
    DBPediaDatatypeHandler, GeoSPARQLDatatypeHandler, RDFDatatypeHandler, VirtuosoGeometryDatatypeHandler, XMLSchemaDatatypeHandler

      public interface DatatypeHandler

  An interface defining methods related to verification and normalization of typed literals and datatype URIs.
  Author:
    Peter Ansell

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static String` | `DBPEDIA` Identifier for datatypes defined by DBPedia.
    `static String` | `GEOSPARQL` Identifier for datatypes defined in the GeoSPARQL vocabulary.
    `static String` | `RDFDATATYPES` Identifier for datatypes defined in the `RDF` vocabulary.
    `static String` | `VIRTUOSOGEOMETRY` Identifier for datatypes defined in the Virtuoso Geometry vocabulary.
    `static String` | `XMLSCHEMA` Identifier for datatypes defined in the `XSD` vocabulary.

  - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `String` | `getKey()` A unique key for this datatype handler to identify it in the DatatypeHandlerRegistry.
    `boolean` | `isRecognizedDatatype(IRI datatypeUri)` Checks if the given datatype URI is recognized by this datatype handler.
    `Literal` | `normalizeDatatype(String literalValue, IRI datatypeUri, ValueFactory valueFactory)` Normalize both the datatype URI and the literal value if appropriate, and use the given value factory to generate a literal matching a literal value and datatype URI.
    `boolean` | `verifyDatatype(String literalValue, IRI datatypeUri)` Verifies that the datatype URI is valid, including a check on the structure of the literal value.

- - ### Field Detail

    - #### XMLSCHEMA

          static final String XMLSCHEMA

      Identifier for datatypes defined in the `XSD` vocabulary.
      See Also:
        Constant Field Values

    - #### RDFDATATYPES

          static final String RDFDATATYPES

      Identifier for datatypes defined in the `RDF` vocabulary.
      See Also:
        Constant Field Values

    - #### DBPEDIA

          static final String DBPEDIA

      Identifier for datatypes defined by DBPedia.
      See Also:
        DBPedia Datatypes, Constant Field Values

    - #### VIRTUOSOGEOMETRY

          static final String VIRTUOSOGEOMETRY

      Identifier for datatypes defined in the Virtuoso Geometry vocabulary.
      See Also:
        Virtuoso Geospatial, Constant Field Values

    - #### GEOSPARQL

          static final String GEOSPARQL

      Identifier for datatypes defined in the GeoSPARQL vocabulary.
      See Also:
        GeoSPARQL, Constant Field Values

  - ### Method Detail

    - #### isRecognizedDatatype

          boolean isRecognizedDatatype(IRI datatypeUri)

      Checks if the given datatype URI is recognized by this datatype handler.
      Parameters:
        `datatypeUri` - The datatype URI to check.
      Returns:
        True if the datatype is syntactically valid and could be used with `verifyDatatype(String, IRI)` and `normalizeDatatype(String, IRI, ValueFactory)`.

    - #### verifyDatatype

          boolean verifyDatatype(String literalValue,
                                 IRI datatypeUri)
                          throws LiteralUtilException

      Verifies that the datatype URI is valid, including a check on the structure of the literal value.

      This method must only be called after verifying that `isRecognizedDatatype(IRI)` returns true for the given datatype URI.

      Parameters:
        `literalValue` - Literal value matching the given datatype URI.
        `datatypeUri` - A datatype URI that matched with `isRecognizedDatatype(IRI)`
      Returns:
        True if the datatype URI is recognized by this datatype handler, and it is verified to be syntactically valid.
      Throws:
        `LiteralUtilException` - If the datatype was not recognized.

    - #### normalizeDatatype

          Literal normalizeDatatype(String literalValue,
                                    IRI datatypeUri,
                                    ValueFactory valueFactory)
                             throws LiteralUtilException

      Normalize both the datatype URI and the literal value if appropriate, and use the given value factory to generate a literal matching a literal value and datatype URI.

      This method must only be called after verifying that `isRecognizedDatatype(IRI)` returns true for the given datatype URI, and `verifyDatatype(String, IRI)` also returns true for the given datatype URI and literal value.

      Parameters:
        `literalValue` - Required literal value to use in the normalization process and to provide the value for the resulting literal.
        `datatypeUri` - The datatype URI which is to be normalized. This URI is available in normalized form from the result using `Literal.getDatatype()`.
        `valueFactory` - The `ValueFactory` to use to create the result literal.
      Returns:
        A `Literal` containing the normalized literal value and datatype URI.
      Throws:
        `LiteralUtilException` - If the datatype URI was not recognized or verified, or the literal value could not be normalized due to an error.

    - #### getKey

          String getKey()

      A unique key for this datatype handler to identify it in the DatatypeHandlerRegistry.
      Returns:
        A unique string key.

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