Package net.sf.saxon.type

Class Converter

java.lang.Object

net.sf.saxon.type.Converter

Direct Known Subclasses:

Converter.DoubleToDecimal, Converter.DoubleToInteger, Converter.DownCastingConverter, Converter.FloatToDecimal, Converter.FloatToInteger, Converter.IdentityConverter, Converter.NumericToDecimal, Converter.NumericToInteger, Converter.PromoterToAnyURI, Converter.PromoterToBase64Binary, Converter.PromoterToDouble, Converter.PromoterToFloat, Converter.PromoterToHexBinary, Converter.PromoterToString, Converter.TwoPhaseConverter, Converter.UnfailingConverter, StringConverter, UntypedSequenceConverter.UntypedConverter

public abstract class Converter
extends Object

A converter implements conversions from one atomic type to another - that is, it implements the casting rules for a (source type, destination type) pair.

There is potentially one Converter implementation for each pair of (source, target) classes; though in many cases the same implementation handles a number of such pairs.

In cases where the conversion rules are fixed (specifically, where they do not depend on differences between versions of the XSD or QT specifications), the appropriate Converter can be obtained as a static constant, for example Converter.BooleanToDouble.INSTANCE. In other cases the converter is parameterized by the ConversionRules object, and should be obtained by calling the appropriate factory method on the ConversionRules.

Where the source type of the conversion is xs:string, the converter will always be a subclass of StringConverter

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Converter.Base64BinaryToHexBinary	Converts base64 to hexBinary
static class	Converter.BooleanToDecimal	Converts a boolean to a decimal
static class	Converter.BooleanToDouble	Converts a boolean to a double
static class	Converter.BooleanToFloat	Converts a boolean to an xs:float
static class	Converter.BooleanToInteger	Converts a boolean to an integer
static class	Converter.DateTimeToDate	Converts a dateTime to a date
static class	Converter.DateTimeToGDay	Converts a dateTime to a gDay
static class	Converter.DateTimeToGMonth	Converts a dateTime to a gMonth
static class	Converter.DateTimeToGMonthDay	Converts a dateTime to a gMonthDay
static class	Converter.DateTimeToGYear	Converts a dateTime to a gYear
static class	Converter.DateTimeToGYearMonth	Converts a dateTime to a gYearMonth
static class	Converter.DateTimeToTime	Converts a dateTime to a time
static class	Converter.DateToDateTime	Converts a date to a dateTime
static class	Converter.DecimalToInteger	Converts a decimal to an integer.
static class	Converter.DoubleToDecimal	Convers a double to a decimal
static class	Converter.DoubleToInteger	Converts a double to an integer
static class	Converter.DownCastingConverter	Converter that checks that a value belonging to a supertype is a valid instance of a subtype, and returns an instance of the subtype
static class	Converter.DurationToDayTimeDuration	Converts a duration to a dayTimeDuration
static class	Converter.DurationToYearMonthDuration	Converts a duration to a yearMonthDuration
static class	Converter.FloatToDecimal	Converts a float to a decimal
static class	Converter.FloatToInteger	Converts a float to an integer
static class	Converter.HexBinaryToBase64Binary	Converts hexBinary to base64Binary
static class	Converter.IdentityConverter	Converter that does nothing - it returns the input unchanged
static class	Converter.IntegerToDecimal	Converts an integer to a decimal
static class	Converter.NotationToQName	Converts Notation to QName
static class	Converter.NumericToBoolean	Converts a numeric value to a boolean
static class	Converter.NumericToDecimal	Converts any numeric value to a decimal
static class	Converter.NumericToDouble	Converts any numeric value to a double.
static class	Converter.NumericToFloat	Converts any numeric value to xs:float
static class	Converter.NumericToInteger	Converts any numeric value to an integer.
static class	Converter.PromoterToAnyURI	Converter that implements the promotion rules from xs:string to xs:anyURI
static class	Converter.PromoterToBase64Binary
static class	Converter.PromoterToDouble	Converter that implements the promotion rules to a required type of xs:double
static class	Converter.PromoterToFloat	Converter that implements the promotion rules to a required type of xs:float
static class	Converter.PromoterToHexBinary	Converter that implements the promotion rules from xs:string to xs:anyURI
static class	Converter.PromoterToString	Converter that implements the promotion rules from xs:anyURI to xs:string
static class	Converter.QNameToNotation	Converts QName to Notation
static class	Converter.ToStringConverter	Converts any value to a string
static class	Converter.ToUntypedAtomicConverter	Converts any value to untyped atomic
static class	Converter.TwoPhaseConverter	Converter that operates in two phases, via an intermediate type
static class	Converter.UnfailingConverter	Specialisation for converters that always succeed
static class	Converter.UpCastingConverter	Converter that does nothing except change the type annotation of the value.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Converter()
protected	Converter(ConversionRules rules)	Construct a converter with a given set of conversion rules.

Method Summary

Modifier and Type	Method	Description
abstract ConversionResult	convert(AtomicValue input)	Convert an atomic value from the source type to the target type
static AtomicValue	convert(AtomicValue value, AtomicType targetType, ConversionRules rules)	Convenience method to convert a given value to a given type.
final ConversionRules	getConversionRules()	Get the conversion rules to be used by this Converter
NamespaceResolver	getNamespaceResolver()	Get the namespace resolver if one has been supplied
boolean	isAlwaysSuccessful()	Ask if this converter will always succeed
boolean	isPromoter()	Ask if this converter implements promotion rules
final void	setConversionRules(ConversionRules rules)	Set the conversion rules to be used by this Converter
Converter	setNamespaceResolver(NamespaceResolver resolver)	Provide a namespace resolver, needed for conversion to namespace-sensitive types such as QName and NOTATION.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Converter

protected Converter()

Converter

protected Converter(ConversionRules rules)

Construct a converter with a given set of conversion rules. For use in constructing subclasses

Parameters:

rules - the conversion rules for the configuration

Method Details

convert

public static AtomicValue convert(AtomicValue value,
 AtomicType targetType,
 ConversionRules rules)
                           throws ValidationException

Convenience method to convert a given value to a given type. Note: it is more efficient to obtain a converter in advance and to reuse it for multiple conversions

Parameters:

value - the value to be converted

targetType - the type to which the value is to be converted

rules - the conversion rules for the configuration

Returns:

the converted value

Throws:

ValidationException - if conversion fails

convert

public abstract ConversionResult convert(AtomicValue input)

Convert an atomic value from the source type to the target type

Parameters:

input - the atomic value to be converted, which the caller guarantees to be of the appropriate type for the converter. The results are undefined if the value is of the wrong type; possible outcomes are (apparent) success, or a ClassCastException.

Returns:

the result of the conversion, as an AtomicValue, if conversion succeeds, or a ValidationFailure object describing the reasons for failure if conversion is not possible. Note that the ValidationFailure object is not (and does not contain) an exception, because it does not necessarily result in an error being thrown, and creating exceptions on non-failure paths is expensive.

setConversionRules

public final void setConversionRules(ConversionRules rules)

Set the conversion rules to be used by this Converter

Parameters:

rules - the conversion rules

getConversionRules

public final ConversionRules getConversionRules()

Get the conversion rules to be used by this Converter

Returns:

the conversion rules

isAlwaysSuccessful

public boolean isAlwaysSuccessful()

Ask if this converter will always succeed

Returns:

true if this Converter will never return a ValidationFailure

isPromoter

public boolean isPromoter()

Ask if this converter implements promotion rules

Returns:

true if this Converter handles type promotion in the coercion rules

setNamespaceResolver

public Converter setNamespaceResolver(NamespaceResolver resolver)

Provide a namespace resolver, needed for conversion to namespace-sensitive types such as QName and NOTATION. The resolver is ignored if the target type is not namespace-sensitive

Parameters:

resolver - the namespace resolver to be used

Returns:

a new Converter customised with the supplied namespace context. The original Converter is unchanged (see bug 2754)

getNamespaceResolver

public NamespaceResolver getNamespaceResolver()

Get the namespace resolver if one has been supplied

Returns:

the namespace resolver, or null if none has been supplied