Package org.eclipse.rdf4j.model.util

Class Literals

  • public class Literals
extends Object
    Various utility methods related to Literal.
    Author:
    Arjohn Kampman, Peter Ansell

    • Constructor Detail

      • Literals

        protected Literals()

    • Method Detail

      • getLabel

        public static String getLabel​(Literal l,
                              String fallback)
        Gets the label of the supplied literal. The fallback value is returned in case the supplied literal is null.
        Parameters:
        l - The literal to get the label for.
        fallback - The value to fall back to in case the supplied literal is null.
        Returns:
        Either the literal's label, or the fallback value.

      • getXsdDatatype

        @Deprecated(since="4.0.0",
            forRemoval=true)
public static Optional<XSD.Datatype> getXsdDatatype​(Literal l)
        Deprecated, for removal: This API element is subject to removal in a future version.
        Use Literal.getCoreDatatype() instead.
        Retrieves the XSD.Datatype value for the supplied Literal, if it has one.
        Parameters:
        l - a Literal
        Returns:
        an Optional XSD.Datatype enum, if one is available. Note that the absence of this enum does not indicate that the literal has no datatype, merely that it has no cached enum representation of that datatype.
        Since:
        3.5.0

      • getByteValue

        public static byte getByteValue​(Literal l,
                                byte fallback)
        Gets the byte value of the supplied literal. The fallback value is returned in case Literal.byteValue() throws a NumberFormatException.
        Parameters:
        l - The literal to get the byte value for.
        fallback - The value to fall back to in case no byte value could gotten from the literal.
        Returns:
        Either the literal's byte value, or the fallback value.

      • getByteValue

        public static byte getByteValue​(Value v,
                                byte fallback)
        Returns the result of getByteValue((Literal)value, fallback) in case the supplied value is a literal, returns the fallback value otherwise.

      • getShortValue

        public static short getShortValue​(Literal l,
                                  short fallback)
        Gets the short value of the supplied literal. The fallback value is returned in case Literal.shortValue() throws a NumberFormatException.
        Parameters:
        l - The literal to get the short value for.
        fallback - The value to fall back to in case no short value could gotten from the literal.
        Returns:
        Either the literal's short value, or the fallback value.

      • getShortValue

        public static short getShortValue​(Value v,
                                  short fallback)
        Returns the result of getShortValue((Literal)value, fallback) in case the supplied value is a literal, returns the fallback value otherwise.

      • getIntValue

        public static int getIntValue​(Literal l,
                              int fallback)
        Gets the int value of the supplied literal. The fallback value is returned in case Literal.intValue() throws a NumberFormatException.
        Parameters:
        l - The literal to get the int value for.
        fallback - The value to fall back to in case no int value could gotten from the literal.
        Returns:
        Either the literal's int value, or the fallback value.

      • getIntValue

        public static int getIntValue​(Value v,
                              int fallback)
        Returns the result of getIntValue((Literal)value, fallback) in case the supplied value is a literal, returns the fallback value otherwise.

      • getLongValue

        public static long getLongValue​(Literal l,
                                long fallback)
        Gets the long value of the supplied literal. The fallback value is returned in case Literal.longValue() throws a NumberFormatException.
        Parameters:
        l - The literal to get the long value for.
        fallback - The value to fall back to in case no long value could gotten from the literal.
        Returns:
        Either the literal's long value, or the fallback value.

      • getLongValue

        public static long getLongValue​(Value v,
                                long fallback)
        Returns the result of getLongValue((Literal)value, fallback) in case the supplied value is a literal, returns the fallback value otherwise.

      • getIntegerValue

        public static BigInteger getIntegerValue​(Literal l,
                                         BigInteger fallback)
        Gets the integer value of the supplied literal. The fallback value is returned in case Literal.integerValue() throws a NumberFormatException.
        Parameters:
        l - The literal to get the integer value for.
        fallback - The value to fall back to in case no integer value could gotten from the literal.
        Returns:
        Either the literal's integer value, or the fallback value.

      • getDecimalValue

        public static BigDecimal getDecimalValue​(Literal l,
                                         BigDecimal fallback)
        Gets the decimal value of the supplied literal. The fallback value is returned in case Literal.decimalValue() throws a NumberFormatException.
        Parameters:
        l - The literal to get the decimal value for.
        fallback - The value to fall back to in case no decimal value could gotten from the literal.
        Returns:
        Either the literal's decimal value, or the fallback value.

      • getFloatValue

        public static float getFloatValue​(Literal l,
                                  float fallback)
        Gets the float value of the supplied literal. The fallback value is returned in case Literal.floatValue() throws a NumberFormatException.
        Parameters:
        l - The literal to get the float value for.
        fallback - The value to fall back to in case no float value could gotten from the literal.
        Returns:
        Either the literal's float value, or the fallback value.

      • getFloatValue

        public static float getFloatValue​(Value v,
                                  float fallback)
        Returns the result of getFloatValue((Literal)value, fallback) in case the supplied value is a literal, returns the fallback value otherwise.

      • getDoubleValue

        public static double getDoubleValue​(Literal l,
                                    double fallback)
        Gets the double value of the supplied literal. The fallback value is returned in case Literal.doubleValue() throws a NumberFormatException.
        Parameters:
        l - The literal to get the double value for.
        fallback - The value to fall back to in case no double value could gotten from the literal.
        Returns:
        Either the literal's double value, or the fallback value.

      • getDoubleValue

        public static double getDoubleValue​(Value v,
                                    double fallback)
        Returns the result of getDoubleValue((Literal)value, fallback) in case the supplied value is a literal, returns the fallback value otherwise.

      • getBooleanValue

        public static boolean getBooleanValue​(Literal l,
                                      boolean fallback)
        Gets the boolean value of the supplied literal. The fallback value is returned in case Literal.booleanValue() throws a NumberFormatException.
        Parameters:
        l - The literal to get the boolean value for.
        fallback - The value to fall back to in case no boolean value could gotten from the literal.
        Returns:
        Either the literal's boolean value, or the fallback value.

      • getBooleanValue

        public static boolean getBooleanValue​(Value v,
                                      boolean fallback)
        Returns the result of getBooleanValue((Literal)value, fallback) in case the supplied value is a literal, returns the fallback value otherwise.

      • getCalendarValue

        public static XMLGregorianCalendar getCalendarValue​(Literal l,
                                                    XMLGregorianCalendar fallback)
        Gets the calendar value of the supplied literal. The fallback value is returned in case Literal.calendarValue() throws a NumberFormatException.
        Parameters:
        l - The literal to get the calendar value for.
        fallback - The value to fall back to in case no calendar value could gotten from the literal.
        Returns:
        Either the literal's calendar value, or the fallback value.

      • getDurationValue

        public static Duration getDurationValue​(Literal l,
                                        Duration fallback)
        Gets the Duration value of the supplied literal. The fallback value is returned in case XMLDatatypeUtil.parseDuration(String) throws an exception.
        Parameters:
        l - The literal to get the Duration value for.
        fallback - The value to fall back to in case no Duration value could gotten from the literal.
        Returns:
        Either the literal's Duration value, or the fallback value.

      • canCreateLiteral

        @Deprecated
public static boolean canCreateLiteral​(Object object)
        Deprecated.
        since 3.5.0
        Helper method for determining whether a literal could be created from an object using a ValueFactory.
        Parameters:
        object - an object to check for the possibility of being converted to a typed literal.
        Returns:
        True if a literal could be created from the given object, based solely on its type and the methods available on the ValueFactory interface and false otherwise. Returns false if the object is null.

      • isLanguageLiteral

        public static boolean isLanguageLiteral​(Literal literal)
        Helper method to determine whether a literal is a language literal, and not a typed literal.
        Parameters:
        literal - The literal to check
        Returns:
        True if the literal has a language tag attached to it and false otherwise.

      • normalizeLanguageTag

        public static String normalizeLanguageTag​(String languageTag)
                                   throws IllformedLocaleException
        Normalizes the given BCP47 language tag according to the rules defined in RFC 5646, section 2.1.1:

        All subtags, including extension and private use subtags, use lowercase letters with two exceptions: two-letter and four-letter subtags that neither appear at the start of the tag nor occur after singletons. Such two-letter subtags are all uppercase (as in the tags "en-CA-x-ca" or "sgn-BE-FR") and four- letter subtags are titlecase (as in the tag "az-Latn-x-latn").
        Parameters:
        languageTag - An unnormalized, valid, language tag
        Returns:
        A normalized version of the given language tag
        Throws:
        IllformedLocaleException - If the given language tag is ill-formed according to the rules specified in BCP47 (RFC 5646).

      • isValidLanguageTag

        public static boolean isValidLanguageTag​(String languageTag)
        Checks if the given string is a well-formed BCP47 language tag according to the rules defined in RFC 5646, section 2.1.1.
        Parameters:
        languageTag - A language tag
        Returns:
        true if the given language tag is well-formed according to the rules specified in BCP47.

      • langMatches

        public static boolean langMatches​(String langTag,
                                  String langRange)
        Implements language range filtering for SPARQL langMatches (https://www.w3.org/TR/sparql11-query/#func-langMatches).
        Parameters:
        langTag - the tag to filter
        langRange - the range to filter against
        Returns:
        true if langTag matches langRange