net.sf.saxon.value
Class ObjectValue

java.lang.Object
  net.sf.saxon.value.Value
      net.sf.saxon.value.AtomicValue
          net.sf.saxon.value.ObjectValue

All Implemented Interfaces:

Serializable, PullEvent, SequenceIterable, GroundedValue, Item, ValueRepresentation, ConversionResult

Direct Known Subclasses:

FirstClassFunction

public class ObjectValue
extends AtomicValue

An XPath value that encapsulates a Java object. Such a value can only be obtained by calling an extension function that returns it.

See Also:

Serialized Form

Field Summary

Fields inherited from class net.sf.saxon.value.Value

EMPTY_CLASS_ARRAY, INDETERMINATE_ORDERING

Fields inherited from interface net.sf.saxon.om.ValueRepresentation

EMPTY_VALUE_ARRAY

Fields inherited from interface net.sf.saxon.om.ValueRepresentation

EMPTY_VALUE_ARRAY

Constructor Summary

ObjectValue()
Default constructor for use in subclasses

ObjectValue(Object object)
Constructor

ObjectValue(Object object, ExternalObjectType type)
Constructor

Method Summary

ConversionResult	convertPrimitive(BuiltInAtomicType requiredType, boolean validate, XPathContext context) Convert to target data type
Object	convertToJava(Class target, XPathContext context) Convert to Java object (for passing to external functions)
AtomicValue	copyAsSubType(AtomicType typeLabel) Create a copy of this atomic value, with a different type label
String	displayTypeName() Display the type name for use in error messages
boolean	effectiveBooleanValue() Get the effective boolean value of the value
boolean	equals(Object other) Determine if two ObjectValues are equal
ItemType	getItemType(TypeHierarchy th) Determine the data type of the items in the expression, if possible
Object	getObject() Get the encapsulated object
BuiltInAtomicType	getPrimitiveType() Determine the primitive type of the value.
Comparable	getSchemaComparable() Get a Comparable value that implements the XML Schema ordering comparison semantics for this value.
String	getStringValue() Get the value as a String
Object	getXPathComparable(boolean ordered, StringCollator collator, XPathContext context) Get an object value that implements the XPath equality and ordering comparison semantics for this value.
int	hashCode()
void	setValue(Object value) Set the value in this object value

Methods inherited from class net.sf.saxon.value.AtomicValue

asAtomic, checkPermittedContents, convert, convert, getCardinality, getComponent, getLength, getStringValueCS, getTypedValue, getTypeLabel, isNaN, itemAt, iterate, process, setTypeLabel, subsequence, toString

Methods inherited from class net.sf.saxon.value.Value

asItem, asItem, asIterator, asValue, convertJavaObjectToXPath, convertToJava, fromItem, getCanonicalLexicalRepresentation, getIterator, iterate, makeQNameValue, reduce, stringToNumber

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ObjectValue

public ObjectValue()

Default constructor for use in subclasses

ObjectValue

public ObjectValue(Object object)

Constructor

Parameters:

object - the object to be encapsulated

ObjectValue

public ObjectValue(Object object,
                   ExternalObjectType type)

Constructor

Parameters:

object - the object to be encapsulated

type - the type of the external object

Method Detail

setValue

public void setValue(Object value)

Set the value in this object value

Parameters:

value - the external value to be wrapped

copyAsSubType

public AtomicValue copyAsSubType(AtomicType typeLabel)

Create a copy of this atomic value, with a different type label

Specified by:

copyAsSubType in class AtomicValue

Parameters:

typeLabel - the type label of the new copy. The caller is responsible for checking that the value actually conforms to this type.

Returns:

the copied value

getPrimitiveType

public BuiltInAtomicType getPrimitiveType()

Determine the primitive type of the value. This delivers the same answer as getItemType().getPrimitiveItemType(). The primitive types are the 19 primitive types of XML Schema, plus xs:integer, xs:dayTimeDuration and xs:yearMonthDuration, and xs:untypedAtomic. For external objects, the result is AnyAtomicType.

Specified by:

getPrimitiveType in class AtomicValue

Returns:

the primitive type

getItemType

public ItemType getItemType(TypeHierarchy th)

Determine the data type of the items in the expression, if possible

Overrides:

getItemType in class AtomicValue

Parameters:

th - The TypeHierarchy.

Returns:

for the default implementation: AnyItemType (not known)

displayTypeName

public String displayTypeName()

Display the type name for use in error messages

Returns:

the type name

convertPrimitive

public ConversionResult convertPrimitive(BuiltInAtomicType requiredType,
                                         boolean validate,
                                         XPathContext context)

Convert to target data type

Parameters:

requiredType - the required atomic type. This must either be a primitive type, or a built-in type derived from the same primitive type as this atomic value.

validate - true if validation is required. If set to false, the caller guarantees that the value is valid for the target data type, and that further validation is therefore not required. Note that a validation failure may be reported even if validation was not requested.

context - The conversion context to be used. This is required at present only when converting to xs:Name or similar types: it determines the NameChecker to be used.

Returns:

the result of the conversion, if successful. If unsuccessful, the value returned will be a ValidationFailure. The caller must check for this condition. No exception is thrown, instead the exception information will be encapsulated within the ValidationFailure.

getStringValue

public String getStringValue()

Get the value as a String

Specified by:

getStringValue in interface Item

Specified by:

getStringValue in interface ValueRepresentation

Specified by:

getStringValue in class AtomicValue

Returns:

a String representation of the value

See Also:

Item.getStringValueCS()

effectiveBooleanValue

public boolean effectiveBooleanValue()
                              throws XPathException

Get the effective boolean value of the value

Overrides:

effectiveBooleanValue in class AtomicValue

Returns:

true, unless the value is boolean false, numeric zero, or zero-length string

Throws:

XPathException - if any dynamic error occurs evaluating the expression

getObject

public Object getObject()

Get the encapsulated object

Returns:

the Java object that this external object wraps

getSchemaComparable

public Comparable getSchemaComparable()

Description copied from class: AtomicValue

Get a Comparable value that implements the XML Schema ordering comparison semantics for this value. An implementation must be provided for all atomic types.

In the case of data types that are partially ordered, the returned Comparable extends the standard semantics of the compareTo() method by returning the value Value.INDETERMINATE_ORDERING when there is no defined order relationship between two given values. This value is also returned when two values of different types are compared.

Specified by:

getSchemaComparable in class AtomicValue

Returns:

a Comparable that follows XML Schema comparison rules

getXPathComparable

public Object getXPathComparable(boolean ordered,
                                 StringCollator collator,
                                 XPathContext context)

Get an object value that implements the XPath equality and ordering comparison semantics for this value. If the ordered parameter is set to true, the result will be a Comparable and will support a compareTo() method with the semantics of the XPath lt/gt operator, provided that the other operand is also obtained using the getXPathComparable() method. In all cases the result will support equals() and hashCode() methods that support the semantics of the XPath eq operator, again provided that the other operand is also obtained using the getXPathComparable() method. A context argument is supplied for use in cases where the comparison semantics are context-sensitive, for example where they depend on the implicit timezone or the default collation.

Specified by:

getXPathComparable in class AtomicValue

Parameters:

ordered - true if an ordered comparison is required. In this case the result is null if the type is unordered; in other cases the returned value will be a Comparable.

collator -

context - the XPath dynamic evaluation context, used in cases where the comparison is context sensitive @return an Object whose equals() and hashCode() methods implement the XPath comparison semantics with respect to this atomic value. If ordered is specified, the result will either be null if no ordering is defined, or will be a Comparable

Returns:

an Object whose equals() and hashCode() methods implement the XPath comparison semantics with respect to this atomic value. If ordered is specified, the result will either be null if no ordering is defined, or will be a Comparable

equals

public boolean equals(Object other)

Determine if two ObjectValues are equal

Specified by:

equals in class AtomicValue

Parameters:

other - the other value

Returns:

true if the other operand is an atomic value and the two values are equal as defined by the XPath eq operator

Throws:

ClassCastException - if they are not comparable

hashCode

public int hashCode()

Overrides:

hashCode in class Object

convertToJava

public Object convertToJava(Class target,
                            XPathContext context)
                     throws XPathException

Convert to Java object (for passing to external functions)

Overrides:

convertToJava in class Value

Parameters:

target - the required target class

context - the XPath dynamic evaluation context

Returns:

the (boxed) Java object that best represents the XPath value

Throws:

XPathException