net.sf.saxon.expr
Class PJConverter

java.lang.Object
  net.sf.saxon.expr.PJConverter

All Implemented Interfaces:

Serializable

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.ToSequenceExtent, PJConverter.ToSequenceIterator, PJConverter.UnwrapExternalObject

public abstract class PJConverter
extends Object
implements Serializable

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

See Also:

Serialized Form

Nested Class Summary

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.ToSequenceExtent
static class	PJConverter.ToSequenceIterator
static class	PJConverter.UnwrapExternalObject

Constructor Summary

PJConverter()

Method Summary

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)
String	compile(String var, Class targetClass, CodeGeneratorService compiler) Generate Java code to implement the type conversion
abstract Object	convert(ValueRepresentation value, Class targetClass, XPathContext context) Convert an XPath value to a Java value of a specified class
static SequenceType	getEquivalentItemType(Class javaClass) Get the nearest XPath equivalent to a Java class.

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

getEquivalentItemType

public static SequenceType getEquivalentItemType(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

convert

public abstract Object convert(ValueRepresentation 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

compile

public String compile(String var,
                      Class targetClass,
                      CodeGeneratorService compiler)

Generate Java code to implement the type conversion

Parameters:

var - the name of a variable whose value will be the XPath ValueRepresentation to be converted

targetClass - the required class of the Java value

compiler - provides supporting services by callback

Returns:

the text of a Java expression whose result will be a Java object/value of the required type

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

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)