org.apache.jena.datatypes

Interface RDFDatatype

All Known Implementing Classes:

BaseDatatype, Functor.FunctorDatatype, XSDbase64Binary, XSDbinary, XSDDatatype, XSDDatatype.XSDGenericType, XSDhexBinary

public interface RDFDatatype

Interface on a datatype representation. An instance of this interface is needed to convert typed literals between lexical and value forms.

Method Summary

Modifier and Type	Method and Description
Object	cannonicalise(Object value) Cannonicalise a java Object value to a normal form.
Object	extendedTypeDefinition() Returns an object giving more details on the datatype.
int	getHashCode(org.apache.jena.graph.impl.LiteralLabel lit) Gets the hash code of a given value.
Class<?>	getJavaClass() If this datatype is used as the cannonical representation for a particular java datatype then return that java type, otherwise returns null.
String	getURI() Return the URI which is the label for this datatype
boolean	isEqual(org.apache.jena.graph.impl.LiteralLabel value1, org.apache.jena.graph.impl.LiteralLabel value2) Compares two instances of values of the given datatype.
boolean	isValid(String lexicalForm) Test whether the given string is a legal lexical form of this datatype.
boolean	isValidLiteral(org.apache.jena.graph.impl.LiteralLabel lit) Test whether the given LiteralLabel is a valid instance of this datatype.
boolean	isValidValue(Object valueForm) Test whether the given object is a legal value form of this datatype.
RDFDatatype	normalizeSubType(Object value, RDFDatatype dt) Normalization.
Object	parse(String lexicalForm) Parse a lexical form of this datatype to a value
String	unparse(Object value) Convert a value of this datatype out to lexical form.

Method Detail

getURI

String getURI()

Return the URI which is the label for this datatype

unparse

String unparse(Object value)

Convert a value of this datatype out to lexical form.

parse

Object parse(String lexicalForm)
      throws DatatypeFormatException

Parse a lexical form of this datatype to a value

Throws:

DatatypeFormatException - if the lexical form is not legal

isValid

boolean isValid(String lexicalForm)

Test whether the given string is a legal lexical form of this datatype.

isValidValue

boolean isValidValue(Object valueForm)

Test whether the given object is a legal value form of this datatype.

isValidLiteral

boolean isValidLiteral(org.apache.jena.graph.impl.LiteralLabel lit)

Test whether the given LiteralLabel is a valid instance of this datatype. This takes into account typing information as well as lexical form - for example an xsd:string is never considered valid as an xsd:integer (even if it is lexically legal like "1").

isEqual

boolean isEqual(org.apache.jena.graph.impl.LiteralLabel value1,
                org.apache.jena.graph.impl.LiteralLabel value2)

Compares two instances of values of the given datatype. This defaults to just testing equality of the java value representation but datatypes can override this. We pass the entire LiteralLabel to allow the equality function to take the xml:lang tag and the datatype itself into account.

getHashCode

int getHashCode(org.apache.jena.graph.impl.LiteralLabel lit)

Gets the hash code of a given value. This defaults to lit.getValue().hashCode(), but datatypes can overide this, and array types must.

getJavaClass

Class<?> getJavaClass()

If this datatype is used as the cannonical representation for a particular java datatype then return that java type, otherwise returns null.

cannonicalise

Object cannonicalise(Object value)

Cannonicalise a java Object value to a normal form. Primarily used in cases such as xsd:integer to reduce the Java object representation to the narrowest of the Number subclasses to ensure that indexing of typed literals works.

extendedTypeDefinition

Object extendedTypeDefinition()

Returns an object giving more details on the datatype. This is type system dependent. In the case of XSD types this will be an instance of org.apache.xerces.impl.xs.dv.XSSimpleType.

normalizeSubType

RDFDatatype normalizeSubType(Object value,
                             RDFDatatype dt)

Normalization. If the value is narrower than the current data type (e.g. value is xsd:date but the time is xsd:datetime) returns the narrower type for the literal. If the type is narrower than the value then it may normalize the value (e.g. set the mask of an XSDDateTime) Currently only used to narrow gener XSDDateTime objects to the minimal XSD date/time type.

Parameters:

value - the current object value

dt - the currently set data type

Returns:

a narrower version of the datatype based on the actual value range