com.saxonica.xqj

Class SaxonXQItem

java.lang.Object

com.saxonica.xqj.Closable

com.saxonica.xqj.SaxonXQItem

All Implemented Interfaces:

SaxonXQItemAccessor, XQItem, XQItemAccessor, XQResultItem

public class SaxonXQItem
extends Closable
implements XQResultItem, SaxonXQItemAccessor

This Saxon class is used to implement both the XQItem and XQResultItem interfaces in XQJ. Where the item is not a real XQResultItem, getConnection() will return null.

Constructor Summary

Constructors

Constructor and Description
SaxonXQItem(Item item, SaxonXQDataFactory factory)

Method Summary

Methods

Modifier and Type	Method and Description
String	getAtomicValue() Gets the current item as a Java String.
boolean	getBoolean() Gets the current item as a boolean.
byte	getByte() Gets the current item as a byte.
XQConnection	getConnection() Gets the XQuery connection associated with this result item
double	getDouble() Gets the current item as a double.
float	getFloat() Gets the current item as a float.
int	getInt() Gets the current item as an int.
XMLStreamReader	getItemAsStream() Read the current item as an XMLStreamReader object, as described in Section 12.1 Serializing an XDM instance into a StAX event stream (XMLStreamReader), XQuery API for Java (XQJ) 1.0.
String	getItemAsString(Properties props) Serializes the current item according to the XSLT 2.0 and XQuery 1.0 serialization.
XQItemType	getItemType() Gets the type of the item.
long	getLong() Gets the current item as a long.
Node	getNode() Gets the item as a DOM node.
URI	getNodeUri() Returns the URI for this item.
Object	getObject() Gets the current item as an Object.
Item	getSaxonItem() Get the current item, in the form of a Saxon Item object.
short	getShort() Gets the current item as a short.
boolean	instanceOf(XQItemType type) Checks if the item "matches" an item type, as defined in 2.5.4.2 Matching an Item Type and an Item, XQuery 1.0: An XML Query Language.
protected static void	validateSerializationProperties(Properties props, Configuration config)
void	writeItem(OutputStream os, Properties props) Serializes the current item to a Writer according to XSLT 2.0 and XQuery 1.0 serialization.
void	writeItem(Writer ow, Properties props) Serializes the current item to a Writer according to XSLT 2.0 and XQuery 1.0 serialization.
void	writeItemToResult(Result result) Writes the current item to a Result.
void	writeItemToSAX(ContentHandler saxHandler) Writes the current item to a SAX handler, as described in in Section 12.2 Serializing an XDM instance into a SAX event stream, XQuery API for Java (XQJ) 1.0.

Methods inherited from class com.saxonica.xqj.Closable

close, isClosed, setClosableContainer

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.xml.xquery.XQItem

close, isClosed

Constructor Detail

SaxonXQItem

public SaxonXQItem(Item item,
           SaxonXQDataFactory factory)

Method Detail

getSaxonItem

public Item getSaxonItem()

Description copied from interface: SaxonXQItemAccessor

Get the current item, in the form of a Saxon Item object. This allows access to non-XQJ methods to manipulate the item, which will not necessarily be stable from release to release. The resulting Item will be an instance of either NodeInfo or AtomicValue.

Specified by:

getSaxonItem in interface SaxonXQItemAccessor

Returns:

the current item

getConnection

public XQConnection getConnection()
                           throws XQException

Description copied from interface: XQResultItem

Gets the XQuery connection associated with this result item

Specified by:

getConnection in interface XQResultItem

Returns:

the connection associated with this result item

Throws:

XQException - if the result item is in a closed state

getAtomicValue

public String getAtomicValue()
                      throws XQException

Description copied from interface: XQItemAccessor

Gets the current item as a Java String. The current item must be an atomic value. This function casts the current item to an xs:string value according to the casting rules defined in 17.1.2 Casting to xs:string and xs:untypedAtomic, XQuery 1.0 and XPath 2.0 Functions and Operators, and then returns the value as a Java String.

Specified by:

getAtomicValue in interface XQItemAccessor

Returns:

the string representation of the item

Throws:

XQException - if (1) there are errors accessing the item's value, (2) the item is not an atomic value, (3) there is an error when casting the item to a string representation, (4) the underlying sequence or item is in a closed state, or (5) in the case of forward only sequences, a get or write method was already invoked on the current item

getBoolean

public boolean getBoolean()
                   throws XQException

Description copied from interface: XQItemAccessor

Gets the current item as a boolean. The current item must be an atomic value of type xs:boolean or a subtype.

Specified by:

getBoolean in interface XQItemAccessor

Returns:

a boolean representing the current item

Throws:

XQException - if (1) the conversion of the current item to a boolean fails, (2) if there are errors accessing the current item, (3) if the underlying sequence or item is in a closed state, or (4) in the case of forward only sequences, a get or write method was already invoked on the current item

getByte

public byte getByte()
             throws XQException

Description copied from interface: XQItemAccessor

Gets the current item as a byte. The current item must be an atomic value of type xs:decimal or a subtype, and its value must be in the value space of byte.

Specified by:

getByte in interface XQItemAccessor

Returns:

a byte representing the current item

Throws:

XQException - if (1) the conversion of the current item to a byte fails, (2) if there are errors accessing the current item, (3) if the underlying sequence or item is in a closed state, or (4) in the case of forward only sequences, a get or write method was already invoked on the current item

getDouble

public double getDouble()
                 throws XQException

Description copied from interface: XQItemAccessor

Gets the current item as a double. The current item must be an atomic value of type xs:double or a subtype.

Specified by:

getDouble in interface XQItemAccessor

Returns:

a double representing the current item

Throws:

XQException - if (1) the conversion of the current item to a double fails, (2) if there are errors accessing the current item, (3) if the underlying sequence or item is in a closed state, or (4) in the case of forward only sequences, a get or write method was already invoked on the current item

getFloat

public float getFloat()
               throws XQException

Description copied from interface: XQItemAccessor

Gets the current item as a float. The current item must be an atomic value of type xs:float or a subtype.

Specified by:

getFloat in interface XQItemAccessor

Returns:

a float representing the current item

Throws:

XQException - if (1) the conversion of the current item to a float fails, (2) if there are errors accessing the current item, (3) if the underlying sequence or item is in a closed state, or (4) in the case of forward only sequences, a get or write method was already invoked on the current item

getInt

public int getInt()
           throws XQException

Description copied from interface: XQItemAccessor

Gets the current item as an int. The current item must be an atomic value of type xs:decimal or a subtype, and its value must be in the value space of int.

Specified by:

getInt in interface XQItemAccessor

Returns:

an int representing the current item

Throws:

XQException - if (1) the conversion of the current item to a int fails, (2) if there are errors accessing the current item, (3) if the underlying sequence or item is in a closed state, or (4) in the case of forward only sequences, a get or write method was already invoked on the current item

getItemAsStream

public XMLStreamReader getItemAsStream()
                                throws XQException

Description copied from interface: XQItemAccessor

Read the current item as an XMLStreamReader object, as described in Section 12.1 Serializing an XDM instance into a StAX event stream (XMLStreamReader), XQuery API for Java (XQJ) 1.0.

Note that the serialization process might fail, in which case a XQException is thrown.

While the stream is being read, the application MUST NOT do any other concurrent operations on the underlying item or sequence. The operation on the stream is undefined if the underlying sequence is repositioned or the state of the underlying item or sequence is changed by concurrent operations.

Specified by:

getItemAsStream in interface XQItemAccessor

Returns:

an XML reader object as XMLStreamReader

Throws:

XQException - if (1) there are errors accessing the current item or the underlying sequence, (2) the underlying sequence or item is in a closed state, (3) in the case of a forward only sequence, a get or write method has already been invoked on the current item, or (4) in case of an error during serialization of the current item into a StAX event stream as defined in Section 12.1 Serializing an XDM instance into a StAX event stream (XMLStreamReader), XQuery API for Java (XQJ) 1.0

getItemAsString

public String getItemAsString(Properties props)
                       throws XQException

Description copied from interface: XQItemAccessor

Serializes the current item according to the XSLT 2.0 and XQuery 1.0 serialization.

Serialization parameters, which influence how serialization is performed, can be specified. Refer to the XSLT 2.0 and XQuery 1.0 serialization and Section 12 Serialization, XQuery API for Java (XQJ) 1.0 for more information.

Specified by:

getItemAsString in interface XQItemAccessor

Parameters:

props - specifies the serialization parameters, null is considered equivalent to an empty Properties object

Returns:

the serialized representation of the item

Throws:

XQException - if (1) there are errors accessing the current item or the underlying sequence, (2) the underlying sequence or item is in a closed state, (3) in the case of a forward only sequence, a get or write method has already been invoked on the current item, or (4) if there are errors during serialization

validateSerializationProperties

protected static void validateSerializationProperties(Properties props,
                                   Configuration config)
                                               throws XQException

Throws:

XQException

getItemType

public XQItemType getItemType()
                       throws XQException

Description copied from interface: XQItemAccessor

Gets the type of the item.

On a forward only sequence this method can be called independent of any other get or write method. It will not raise an error if such method has been called already, nor will it affect subsequent invocations of any other get or write method.

Specified by:

getItemType in interface XQItemAccessor

Returns:

the type of the item

Throws:

XQException - if (1) there are errors accessing the type of the item, or (2) the underlying sequence or item is in a closed state

getLong

public long getLong()
             throws XQException

Description copied from interface: XQItemAccessor

Gets the current item as a long. The current item must be an atomic value of type xs:decimal or a subtype, and its value must be in the value space of long.

Specified by:

getLong in interface XQItemAccessor

Returns:

a long representing the current item

Throws:

XQException - if (1) the conversion of the current item to a long fails, (2) if there are errors accessing the current item, (3) if the underlying sequence or item is in a closed state, or (4) in the case of forward only sequences, a get or write method was already invoked on the current item

getNode

public Node getNode()
             throws XQException

Description copied from interface: XQItemAccessor

Gets the item as a DOM node. The current item must be a node. The type of the returned DOM node is governed by Table 7 - XQuery Node Types and Corresponding Java Object Types XQuery API for Java (XQJ) 1.0

The instance of the returned node is implementation dependent. The node may be a reference or a copy of the internal state of the item. It is advisable to make a copy of the node if the application plans to modify it.

Specified by:

getNode in interface XQItemAccessor

Returns:

a DOM node representing the current item

Throws:

XQException - if (1) if there are errors accessing the current item, (2) the current item is not a node, (3) if the underlying sequence or item is in a closed state, or (4) in the case of forward only sequences, a get or write method was already invoked on the current item

getNodeUri

public URI getNodeUri()
               throws XQException

Description copied from interface: XQItemAccessor

Returns the URI for this item. If the item is a document node, then this method returns the absolute URI of the resource from which the document node was constructed. If the document URI is not available, then the empty string is returned. If the document URI is available, the returned value is the same as if fn:document-uri were evaluated on this document node. If the item is of a node kind other than document node, then the returned URI is implementation-defined.

On a forward only sequence this method can be called independent of any other get or write method. It will not raise an error if such method has been called already, nor will it affect subsequent invocations of any other get or write method on the current item.

Specified by:

getNodeUri in interface XQItemAccessor

Returns:

the document URI for this document node or the empty string if not available. For other node kinds, the result is implementation-defined

Throws:

XQException - if (1) if there are errors accessing the current item, (2) the current item is not a node, (3) if the underlying sequence or item is in a closed state

getObject

public Object getObject()
                 throws XQException

Description copied from interface: XQItemAccessor

Gets the current item as an Object.

The data type of the returned object will be the Java Object type as specified in 14.4 Mapping an XQuery Atomic Value to a Java Object Type and 14.5 Mapping an XQuery Node to a Java Object Type, XQuery API for Java (XQJ) 1.0.

Specified by:

getObject in interface XQItemAccessor

Returns:

an object representing the current item

Throws:

XQException - if (1) if there are errors accessing the current item, (2) if the underlying sequence or item is in a closed state, or (3) in the case of forward only sequences, a get or write method was already invoked on the current item

getShort

public short getShort()
               throws XQException

Description copied from interface: XQItemAccessor

Gets the current item as a short. The current item must be an atomic value of type xs:decimal or a subtype, and its value must be in the value space of short.

Specified by:

getShort in interface XQItemAccessor

Returns:

a short representing the current item

Throws:

XQException - if (1) the conversion of the current item to a short fails, (2) if there are errors accessing the current item, (3) if the underlying sequence or item is in a closed state, or (4) in the case of forward only sequences, a get or write method was already invoked on the current item

instanceOf

public boolean instanceOf(XQItemType type)
                   throws XQException

Description copied from interface: XQItemAccessor

Checks if the item "matches" an item type, as defined in 2.5.4.2 Matching an Item Type and an Item, XQuery 1.0: An XML Query Language.

You can use this method to first check the type of the result before calling the specific get methods.

Example -

  ...
  XQItemType strType = conn.createAtomicType(XQItemType.XQBASETYPE_STRING);
  XQItemType nodeType = conn.createNodeType();

  XQSequence result = preparedExpr.executeQuery();
  while (result.next())
  {
     // Generic check for node..
     if (result.instanceOf(nodeType))
        org.w3.dom.Node node = result.getNode();
     else if (result.instanceOf(strType))
        String str = result.getAtomicValue();
   }
 

If either the type of the XQItemAccessor or the input XQItemType is not a built-in type, then this method is allowed to raise exception if it can NOT determine the instanceOf relationship due to the lack of the access of the XML schema that defines the user defined schema types if the XQMetaData.isUserDefinedXMLSchemaTypeSupported() method returns false.
Otherwise, this method must determine if the type of the XQItemAccessor is an instance of the input XQItemType. Note even if isUserDefinedXMLSchemaTypeSupported() returns false, an XQJ implementation may still be able to determine the instanceOf relationship for certain cases involving user defined schema type. For example, if the type of an XQItemAccessor is of mySchema:hatSize sequence type and the input parameter XQItemType is of item() sequence type, the return value for instanceOf relationship should always be true even though the XQJ implementation does not know the precise type information of mySchema:hatSize type defined in XML schema 'mySchema'.

Specified by:

instanceOf in interface XQItemAccessor

Parameters:

type - item type to match

Returns:

true if this item matches the input item type as defined in 2.5.4.2 Matching an Item Type and an Item, XQuery 1.0: An XML Query Language, and false if it does not

Throws:

XQException - if (1) there are errors accessing the item's type, (2) if the underlying sequence or item is in a closed state, (3) if the implementation is unable to determine the schema definition of a user defined schema type, or (4) the type parameter is null

writeItem

public void writeItem(OutputStream os,
             Properties props)
               throws XQException

Description copied from interface: XQItemAccessor

Serializes the current item to a Writer according to XSLT 2.0 and XQuery 1.0 serialization.

Serialization parameters, which influence how serialization is performed, can be specified. Refer to the XSLT 2.0 and XQuery 1.0 serialization and Section 12 Serialization, XQuery API for Java (XQJ) 1.0 for more information.

Specified by:

writeItem in interface XQItemAccessor

Parameters:

os - the output stream into which the current item is to be serialized

props - specifies the serialization parameters, null is considered equivalent to an empty Properties object

Throws:

XQException - if (1) there are errors accessing the current item or the underlying sequence, (2) the underlying sequence or item is in a closed state, (3) in the case of a forward only sequence, a get or write method has already been invoked on the current item, (4) if there are errors during serialization, or (5) the os parameter is null

writeItem

public void writeItem(Writer ow,
             Properties props)
               throws XQException

Description copied from interface: XQItemAccessor

Serializes the current item to a Writer according to XSLT 2.0 and XQuery 1.0 serialization.

Serialization parameters, which influence how serialization is performed, can be specified. Refer to the XSLT 2.0 and XQuery 1.0 serialization and Section 12 Serialization, XQuery API for Java (XQJ) 1.0 for more information.

Warning: When outputting to a Writer, make sure the writer's encoding matches the encoding parameter if specified as a property or the default encoding.

Specified by:

writeItem in interface XQItemAccessor

Parameters:

ow - the writer object into which the current item is to be serialized

props - specifies the serialization parameters, null is considered equivalent to an empty Properties object

Throws:

XQException - if (1) there are errors accessing the current item or the underlying sequence, (2) the underlying sequence or item is in a closed state, (3) in the case of a forward only sequence, a get or write method has already been invoked on the current item, (4) if there are errors during serialization, or (5) the ow parameter is null

writeItemToResult

public void writeItemToResult(Result result)
                       throws XQException

Description copied from interface: XQItemAccessor

Writes the current item to a Result. First the item is normalized as described in XSLT 2.0 and XQuery 1.0 serialization. Subsequently it is serialized to the Result object.

Note that the normalization process can fail, in which case an XQException is thrown.

An XQJ implementation must at least support the following implementations:

• javax.xml.transform.dom.DOMResult
• javax.xml.transform.sax.SAXResult
• javax.xml.transform.stream.StreamResult

Specified by:

writeItemToResult in interface XQItemAccessor

Parameters:

result - the result object into which the item is to be serialized

Throws:

XQException - if (1) there are errors accessing the current item or the underlying sequence, (2) the underlying sequence or item is in a closed state, (3) in the case of a forward only sequence, a get or write method has already been invoked on the current item, (4) in case of an error while serializing the current item into the Result object, or (5) the result parameter is null

writeItemToSAX

public void writeItemToSAX(ContentHandler saxHandler)
                    throws XQException

Description copied from interface: XQItemAccessor

Writes the current item to a SAX handler, as described in in Section 12.2 Serializing an XDM instance into a SAX event stream, XQuery API for Java (XQJ) 1.0.

Note that the serialization process might fail, in which case a XQException is thrown.

The specified org.xml.sax.ContentHandler can optionally implement the org.xml.sax.LexicalHandler interface. An implementation must check if the specified ContentHandler implements LexicalHandler. If the handler is a LexicalHandler comment nodes are reported, otherwise they will be silently ignored.

Specified by:

writeItemToSAX in interface XQItemAccessor

Parameters:

saxHandler - the SAX content handler, optionally a lexical handler

Throws:

XQException - if (1) there are errors accessing the current item or the underlying sequence, (2) the underlying sequence or item is in a closed state, (3) in the case of a forward only sequence, a get or write method has already been invoked on the current item, (4) in case of an error while serializing the XDM instance into a SAX event stream, or (5) the saxhdlr parameter is null