Package 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 | Description
    --- | ---
    `SaxonXQItem​(Item item, SaxonXQDataFactory factory)` |

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `java.lang.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`.
    `javax.xml.stream.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.
    `java.lang.String` | `getItemAsString​(java.util.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`.
    `org.w3c.dom.Node` | `getNode()` | Gets the item as a DOM node.
    `java.net.URI` | `getNodeUri()` | Returns the URI for this item.
    `java.lang.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​(java.util.Properties props, Configuration config)` |
    `void` | `writeItem​(java.io.OutputStream os, java.util.Properties props)` | Serializes the current item to a `Writer` according to XSLT 2.0 and XQuery 1.0 serialization.
    `void` | `writeItem​(java.io.Writer ow, java.util.Properties props)` | Serializes the current item to a `Writer` according to XSLT 2.0 and XQuery 1.0 serialization.
    `void` | `writeItemToResult​(javax.xml.transform.Result result)` | Writes the current item to a `Result`.
    `void` | `writeItemToSAX​(org.xml.sax.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 java.lang.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 javax.xml.stream.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 java.lang.String getItemAsString​(java.util.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​(java.util.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 org.w3c.dom.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 java.net.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 java.lang.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​(java.io.OutputStream os,
                                java.util.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​(java.io.Writer ow,
                                java.util.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​(javax.xml.transform.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​(org.xml.sax.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`