net.sf.saxon.expr

Class PJConverter

java.lang.Object

net.sf.saxon.expr.PJConverter

Direct Known Subclasses:

PJConverter.AnyURIValueToURI, PJConverter.AnyURIValueToURL, PJConverter.Atomic, PJConverter.BooleanValueToBoolean, PJConverter.CalendarValueToCalendar, PJConverter.CalendarValueToDate, PJConverter.General, PJConverter.Identity, PJConverter.IntegerValueToBigInteger, PJConverter.IntegerValueToByte, PJConverter.IntegerValueToChar, PJConverter.IntegerValueToInt, PJConverter.IntegerValueToLong, PJConverter.IntegerValueToShort, PJConverter.NumericValueToBigDecimal, PJConverter.NumericValueToDouble, PJConverter.NumericValueToFloat, PJConverter.QualifiedNameValueToQName, PJConverter.StringValueToChar, PJConverter.StringValueToString, PJConverter.ToArray, PJConverter.ToCollection, PJConverter.ToNull, PJConverter.ToOne, PJConverter.ToOneOrMore, PJConverter.ToSequenceExtent, PJConverter.ToSequenceIterator, PJConverter.ToZeroOrMore, PJConverter.ToZeroOrOne, PJConverter.UnwrapExternalObject

public abstract class PJConverter
extends Object

This class together with its embedded subclasses handles conversion from XPath values to Java values

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PJConverter.AnyURIValueToURI
static class	PJConverter.AnyURIValueToURL
static class	PJConverter.Atomic Converter for use when the source object is an atomic value, but nothing more is known statically.
static class	PJConverter.BooleanValueToBoolean
static class	PJConverter.CalendarValueToCalendar
static class	PJConverter.CalendarValueToDate
static class	PJConverter.General General-purpose converter when nothing more specific is available.
static class	PJConverter.Identity
static class	PJConverter.IntegerValueToBigInteger
static class	PJConverter.IntegerValueToByte
static class	PJConverter.IntegerValueToChar
static class	PJConverter.IntegerValueToInt
static class	PJConverter.IntegerValueToLong
static class	PJConverter.IntegerValueToShort
static class	PJConverter.NumericValueToBigDecimal
static class	PJConverter.NumericValueToDouble
static class	PJConverter.NumericValueToFloat
static class	PJConverter.QualifiedNameValueToQName
static class	PJConverter.StringValueToChar
static class	PJConverter.StringValueToString
static class	PJConverter.ToArray Converter for use when the target class is an array
static class	PJConverter.ToCollection Converter for use when the target class is a collection class.
static class	PJConverter.ToNull
static class	PJConverter.ToOne Converter for use when the target class is One, which constrains the value to be a singleton
static class	PJConverter.ToOneOrMore Converter for use when the target class is OneOrMore, which constrains the value to be a non-empty sequence
static class	PJConverter.ToSequenceExtent
static class	PJConverter.ToSequenceIterator
static class	PJConverter.ToZeroOrMore Converter for use when the target class is ZeroOrMore, which allows any sequence but is a generic (parameterized) class so there is compile-time information about the type of items
static class	PJConverter.ToZeroOrOne Converter for use when the target class is ZeroOrOne, which constrains the value to be a singleton or an empty sequence
static class	PJConverter.UnwrapExternalObject

Constructor Summary

Constructors

Constructor and Description
PJConverter()

Method Summary

Methods

Modifier and Type	Method and Description
static PJConverter	allocate(Configuration config, ItemType itemType, int cardinality, Class targetClass) Factory method to instantiate a converter from a given XPath type to a given Java class
static PJConverter	allocateNodeListCreator(Configuration config, Object node) Static method to get a converter from an XPath sequence of nodes to the representation of a NodeList in an external object model (this is really a special for DOM, which uses NodeList rather than general purpose Java collection classes)
abstract Object	convert(Sequence value, Class targetClass, XPathContext context) Convert an XPath value to a Java value of a specified class
static SequenceType	getEquivalentSequenceType(Class javaClass) Get the nearest XPath equivalent to a Java class.
static SequenceType	getParameterizedSequenceType(Type javaType) Get the nearest XPath equivalent to a Java parameterized type.

Methods inherited from class java.lang.Object

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

Constructor Detail

PJConverter

public PJConverter()

Method Detail

getEquivalentSequenceType

public static SequenceType getEquivalentSequenceType(Class javaClass)

Get the nearest XPath equivalent to a Java class. A function call will be type-checked against an XPath function signature in which the Java classes are replaced by their nearest equivalent XPath types

Parameters:

javaClass - a Java class

Returns:

the nearest equivalent XPath SequenceType

getParameterizedSequenceType

public static SequenceType getParameterizedSequenceType(Type javaType)

Get the nearest XPath equivalent to a Java parameterized type. The only parameterized types we recognize are those like Sequence<StringValue> which correspond exactly to an XPath SequenceType.

Parameters:

javaType - a parameterized Java class

Returns:

the nearest equivalent XPath SequenceType

convert

public abstract Object convert(Sequence value,
             Class targetClass,
             XPathContext context)
                        throws XPathException

Convert an XPath value to a Java value of a specified class

Parameters:

value - the supplied XPath value

targetClass - the class of the required Java value

context - the XPath dynamic context

Returns:

the corresponding Java value, which is guaranteed to be an instance of the target class (except that an empty sequence is converted to null)

Throws:

XPathException - if the conversion is not possible or fails

allocate

public static PJConverter allocate(Configuration config,
                   ItemType itemType,
                   int cardinality,
                   Class targetClass)
                            throws XPathException

Factory method to instantiate a converter from a given XPath type to a given Java class

Parameters:

config - the Saxon Configuration

itemType - the item type of the XPath value to be converted

cardinality - the cardinality of the XPath value to be converted

targetClass - the Java class required for the conversion result

Returns:

a suitable converter

Throws:

XPathException - if no conversion is possible

allocateNodeListCreator

public static PJConverter allocateNodeListCreator(Configuration config,
                                  Object node)

Static method to get a converter from an XPath sequence of nodes to the representation of a NodeList in an external object model (this is really a special for DOM, which uses NodeList rather than general purpose Java collection classes)

Parameters:

config - the Saxon configuration

node - an object representing a node in an external model

Returns:

the Java object representing the external node