net.sf.saxon.s9api

Class XdmItem

java.lang.Object

net.sf.saxon.s9api.XdmValue

net.sf.saxon.s9api.XdmItem

All Implemented Interfaces:

java.lang.Iterable<XdmItem>

Direct Known Subclasses:

XdmAtomicValue, XdmExternalObject, XdmFunctionItem, XdmNode

public abstract class XdmItem
extends XdmValue

The class XdmItem represents an item in a sequence, as defined by the XDM data model. An item is either an atomic value or a node.

An item is a member of a sequence, but it can also be considered as a sequence (of length one) in its own right. XdmItem is a subtype of XdmValue because every Item in the XDM data model is also a value.

It cannot be assumed that every sequence of length one will be represented by an XdmItem. It is quite possible for an XdmValue that is not an XdmItem to hold a singleton sequence.

Saxon provides two concrete subclasses of XdmItem, namely XdmNode and XdmAtomicValue. Users must not attempt to create additional subclasses.

Constructor Summary

Constructors

Constructor and Description
XdmItem(Item item) Construct an XdmItem as a wrapper around an existing Saxon Item object

Method Summary

Modifier and Type	Method and Description
java.util.Map<XdmAtomicValue,XdmValue>	asMap() If this item is a map, return a corresponding Java Map.
java.lang.String	getStringValue() Get the string value of the item.
Item	getUnderlyingValue() Get the underlying implementation object representing the value.
UnicodeString	getUnicodeStringValue() Get the string value of the item.
boolean	isAtomicValue() Determine whether the item is an atomic value or some other type of item
boolean	isNode() Determine whether the item is a node or some other type of item
boolean	matches(ItemType type) Determine whether this item matches a given item type.
int	size() Get the number of items in the sequence
XdmStream<? extends XdmItem>	stream() Get a stream comprising the items in this value
protected static XdmAtomicValue	wrapItem(AtomicValue item)
protected static XdmItem	wrapItem(Item item)
protected static XdmNode	wrapItem(NodeInfo item)

Methods inherited from class net.sf.saxon.s9api.XdmValue

append, documentOrder, isEmpty, itemAt, iterator, makeSequence, makeValue, select, subsequence, toString, wrap, wrap

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

XdmItem

public XdmItem(Item item)

Construct an XdmItem as a wrapper around an existing Saxon Item object

Parameters:

item - the Item object to be wrapped. This can be retrieved using the getUnderlyingValue() method.

Throws:

java.lang.NullPointerException - if item is null

Since:

9.5 (previously a protected constructor)

Method Detail

wrapItem

protected static XdmItem wrapItem(Item item)

wrapItem

protected static XdmNode wrapItem(NodeInfo item)

wrapItem

protected static XdmAtomicValue wrapItem(AtomicValue item)

getUnderlyingValue

public Item getUnderlyingValue()

Get the underlying implementation object representing the value. This method allows access to lower-level Saxon functionality, including classes and methods that offer no guarantee of stability across releases.

Overrides:

getUnderlyingValue in class XdmValue

Returns:

the underlying implementation object representing the value

Since:

9.8 (previously inherited from XdmValue which returns a Sequence)

getStringValue

public java.lang.String getStringValue()

Get the string value of the item. For a node, this gets the string value of the node. For an atomic value, it has the same effect as casting the value to a string. In all cases the result is the same as applying the XPath string() function.

For atomic values, the result is the same as the result of calling toString. This is not the case for nodes, where toString returns an XML serialization of the node.

Returns:

the result of converting the item to a string.

getUnicodeStringValue

public UnicodeString getUnicodeStringValue()

Get the string value of the item. For a node, this gets the string value of the node. For an atomic value, it has the same effect as casting the value to a string. In all cases the result is the same as applying the XPath string() function.

The string returned is the same as the result of getStringValue(), but represented as an instance of UnicodeString.

Returns:

the result of converting the item to a string.

isNode

public boolean isNode()

Determine whether the item is a node or some other type of item

Returns:

true if the item is a node, false if it is an atomic value or a function (including maps and arrays)

Since:

10.0

isAtomicValue

public boolean isAtomicValue()

Determine whether the item is an atomic value or some other type of item

Returns:

true if the item is an atomic value, false if it is a node or a function (including maps and arrays)

size

public int size()

Get the number of items in the sequence

Overrides:

size in class XdmValue

Returns:

the number of items in the value. For an item (including a map or array) this is always 1 (one).

asMap

public java.util.Map<XdmAtomicValue,XdmValue> asMap()

If this item is a map, return a corresponding Java Map.

Returns:

if this item is a map, return a mutable Map from atomic values to (sequence) values, containing the same entries as this map. Otherwise return null.

Since:

9.6.

stream

public XdmStream<? extends XdmItem> stream()

Get a stream comprising the items in this value

Overrides:

stream in class XdmValue

Returns:

a Stream over the items in this value

Since:

9.9

matches

public boolean matches(ItemType type)

Determine whether this item matches a given item type.

Parameters:

type - the item type to be tested against this item

Returns:

true if the item matches this item type, false if it does not match.

Since:

9.9