io::zorba::api::xqj::ZorbaXQResultItem

Inherited from: io.zorba.api.xqj.ZorbaXQItem

This class represents an immutable item object obtained from an XQResultSequence using the getItem method. A forward only result sequence does not support calling the getter methods multiple times on the same item. To work around this case, the getItem method can be used to obtain a result item and then getter methods may be called multiple times on this item.The ZorbaXQResultItem object is dependent on the connection, expression and the sequence from which it was created and is only valid for the duration of those objects. Thus, if any one of those objects is closed, this ZorbaXQResultItem object will be implicitly closed, and it can no longer be used. Similarly re-executing the expression also implicitly closes the associated result sequences, which in turn implicitly closes this result item.An XQJ driver is not required to provide finalizer methods for the connection and other objects. Hence it is strongly recommended that users call close method explicitly to free any resources. It is also recommended that they do so under a final block to ensure that the object is closed even when there are exceptions. Not closing this object implicitly or explicitly might result in serious memory leaks.Example -
 {.java}
 
   XQPreparedExpression expr = conn.prepareExpression("for $i ..");
   XQResultSequence result = expr.executeQuery();
 
   // posititioned before the first item
   while (result.next())
   {
     ZorbaXQResultItem item = result.getItem();
     // perform multiple gets on this item 
     // get DOM
     org.w3.dom.Node node = item.getNode(); 
     // get SAX
     item.writeItemToSAX(saxHandler);
  
     item.close();  // good practice.  Item will get implicitly closed
                    // when the expression,  connection or sequence is closed.
   }
 
   result.close(); // explicitly close the result sequence

Private Attributes

XQConnection

connection

Public Functions

void

close()

Close the item and release all the resources associated with this item.

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.

String

getItemAsString(Properties prprts)

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.

short

getShort()

Gets the current item as a short.

boolean

instanceOf(XQItemType xqit)

Checks if the item "matches" an item type.

boolean

isClosed()

Checks if the item is closed.

void

writeItem(OutputStream out, Properties prprts)

Serializes the current item to a Writer.

void

writeItem(Writer writer, Properties prprts)

Serializes the current item to a Writer.

void

writeItemToResult(Result result)

Writes the current item to a Result.

void

writeItemToSAX(ContentHandler ch)

Writes the current item to a SAX handler.

ZorbaXQResultItem(Item item, XQConnection conn)

Protected Functions

Item

getZorbaItem()

Private Attributes

connection

XQConnection connection

Public Functions

close

void close()

Close the item and release all the resources associated with this item.

No method other than the isClosed or close method may be called once the item is closed. Calling close on an ZorbaXQItem object that is already closed has no effect.

Parameters

XQException - if there is an error during closing the item

getAtomicValue

String getAtomicValue()

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.

Returns

the string representation of the item

Parameters

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

boolean getBoolean()

Gets the current item as a boolean.

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

Returns

a boolean representing the current item

Parameters

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

byte getByte()

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.

Returns

a byte representing the current item

Parameters

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

getConnection

XQConnection getConnection()

Gets the XQuery connection associated with this result item.

Returns

the connection associated with this result item

Parameters

XQException - if the result item is in a closed state

getDouble

double getDouble()

Gets the current item as a double.

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

Returns

a double representing the current item

Parameters

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

float getFloat()

Gets the current item as a float.

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

Returns

a float representing the current item

Parameters

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

int getInt()

Gets the current item as an int.

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.

Returns

an int representing the current item

Parameters

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

XMLStreamReader getItemAsStream()

Read the current item as an XMLStreamReader object.

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.

Returns

an XML reader object as XMLStreamReader

Parameters

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

String getItemAsString(Properties prprts)

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.

Parameters

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

Returns

the serialized representation of the item

Parameters

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

getItemType

XQItemType getItemType()

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.

Returns

the type of the item

Parameters

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

long getLong()

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.

Returns

a long representing the current item

Parameters

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

Node getNode()

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.

Returns

a DOM node representing the current item

Parameters

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

URI getNodeUri()

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.

Returns

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

Parameters

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

Object getObject()

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.

Returns

an object representing the current item

Parameters

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

short getShort()

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.

Returns

a short representing the current item

Parameters

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

boolean instanceOf(XQItemType xqit)

Checks if the item "matches" an item 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. You can use this method to first check the type of the result before calling the specific get methods.Example -

 {.java}
   ...
   ZorbaXQItemType strType = conn.createAtomicType(ZorbaXQItemType.XQBASETYPE_STRING);
   ZorbaXQItemType 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 ZorbaXQItemType 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 ZorbaXQItemType. 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 ZorbaXQItemType 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'.

Parameters

xqit - 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

Parameters

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

isClosed

boolean isClosed()

Checks if the item is closed.

Returns

boolean true if the item is in a closed state, false otherwise

writeItem

void writeItem(OutputStream out, Properties prprts)

Serializes the current item to a Writer.

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.

Parameters

out - the output stream into which the current item is to be serialized
prprts - specifies the serialization parameters, null is considered equivalent to an empty Properties object

Parameters

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

void writeItem(Writer writer, Properties prprts)

Serializes the current item to a Writer.

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.

Parameters

writer - the output stream into which the current item is to be serialized
prprts - specifies the serialization parameters, null is considered equivalent to an empty Properties object

Parameters

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

writeItemToResult

void writeItemToResult(Result result)

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

Parameters

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

Parameters

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

void writeItemToSAX(ContentHandler ch)

Writes the current item to a SAX handler.

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.

Parameters

ch - the SAX content handler, optionally a lexical handler

Parameters

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

ZorbaXQResultItem

 ZorbaXQResultItem(Item item, XQConnection conn)

Protected Functions

getZorbaItem

Item getZorbaItem()