Package org.eclipse.rdf4j.rio

Interface LanguageHandler

  • All Known Implementing Classes:
    BCP47LanguageHandler, RFC3066LanguageHandler
    public interface LanguageHandler
    An interface defining methods related to verification and normalization of language tags.

    The language handler may optionally provide normalization and verification services for string literals based on the language tags, including translation, grammar and spelling checks. However, this behavior is entirely driven by the user.

    Author:
    Peter Ansell

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static String BCP47
      Identifier for the language tag format defined by BCP47, which is referenced by the RDF-1.1 specification.
      static String RFC3066
      Identifier for the language tag format defined by RFC3066, which is referenced by the RDF-1.0 specification.
      static String RFC4646
      Identifier for the language tag format defined by RFC4646, which obsoletes RFC3066, but which is not referenced by the RDF specification.

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      String getKey()
      A unique key for this language handler to identify it in the LanguageHandlerRegistry.
      boolean isRecognizedLanguage​(String languageTag)
      Checks if the given language tag is recognized by this language handler, including cases where the language tag is considered syntactically well-formed, but is not yet normalized.
      Literal normalizeLanguage​(String literalValue, String languageTag, ValueFactory valueFactory)
      Normalize both the language tag and the language if appropriate, and use the given value factory to generate a literal matching the literal value and language tag.
      boolean verifyLanguage​(String literalValue, String languageTag)
      Verifies that the language tag is syntactically well-formed, optionally including an automated check on the literal value being a match for the given tag.

    • Field Detail

      • RFC3066

        static final String RFC3066
        Identifier for the language tag format defined by RFC3066, which is referenced by the RDF-1.0 specification.
        See Also:
        Constant Field Values

      • RFC4646

        static final String RFC4646
        Identifier for the language tag format defined by RFC4646, which obsoletes RFC3066, but which is not referenced by the RDF specification.
        See Also:
        Constant Field Values

      • BCP47

        static final String BCP47
        Identifier for the language tag format defined by BCP47, which is referenced by the RDF-1.1 specification.
        See Also:
        Constant Field Values

    • Method Detail

      • isRecognizedLanguage

        boolean isRecognizedLanguage​(String languageTag)
        Checks if the given language tag is recognized by this language handler, including cases where the language tag is considered syntactically well-formed, but is not yet normalized.
        Parameters:
        languageTag - The language tag to check.
        Returns:
        True if the language tag is syntactically well-formed and could be used with verifyLanguage(String, String) and normalizeLanguage(String, String, ValueFactory).

      • verifyLanguage

        boolean verifyLanguage​(String literalValue,
                       String languageTag)
                throws LiteralUtilException
        Verifies that the language tag is syntactically well-formed, optionally including an automated check on the literal value being a match for the given tag.

        This method must only be called after verifying that isRecognizedLanguage(String) returns true for the given language tag.

        Parameters:
        literalValue - Literal value matching the given language tag.
        languageTag - A language tag that matched with isRecognizedLanguage(String).
        Returns:
        True if the language tag is recognized by this language handler, and it is verified to be syntactically valid.
        Throws:
        LiteralUtilException - If the language tag was not recognized.

      • normalizeLanguage

        Literal normalizeLanguage​(String literalValue,
                          String languageTag,
                          ValueFactory valueFactory)
                   throws LiteralUtilException
        Normalize both the language tag and the language if appropriate, and use the given value factory to generate a literal matching the literal value and language tag.

        This method must only be called after verifying that isRecognizedLanguage(String) returns true for the given language tag, and verifyLanguage(String, String) also returns true for the given language and literal value.

        Parameters:
        literalValue - Required literal value to use in the normalization process and to provide the value for the resulting literal.
        languageTag - The language tag which is to be normalized. This tag is available in normalized form from the result using Literal.getLanguage().
        valueFactory - The ValueFactory to use to create the result literal.
        Returns:
        A Literal containing the normalized literal value and language tag.
        Throws:
        LiteralUtilException - If the language tag 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 language handler to identify it in the LanguageHandlerRegistry.
        Returns:
        A unique string key.