## net.sf.saxon.xqj
Class SaxonXQPreparedExpression

    java.lang.Object
      net.sf.saxon.xqj.Closable
          net.sf.saxon.xqj.SaxonXQDynamicContext
              net.sf.saxon.xqj.SaxonXQPreparedExpression

All Implemented Interfaces:
  XQDynamicContext, XQPreparedExpression

    public class SaxonXQPreparedExpression

extends SaxonXQDynamicContext
implements XQPreparedExpression

Saxon implementation of the XQJ interface XQPreparedExpression. This represents a compiled XQuery expression, together with the dynamic context for its evaluation. Note that this means the object should not be used in more than one thread concurrently.

Note that an expression is scrollable or not depending on the scrollability property of the XQConnection that was used to compile this expression (at the time it was compiled). If the expression is scrollable then its results are delivered in an XQSequence that supports scrolling backwards as well as forwards.

For full Javadoc details, see the XQJ interface specification.

Field Summary

Fields inherited from class net.sf.saxon.xqj.SaxonXQDynamicContext
`connection`

Constructor Summary
`protected` `SaxonXQPreparedExpression(SaxonXQConnection connection, XQueryExpression expression, SaxonXQStaticContext sqc, DynamicQueryContext context)`

Method Summary
`void` `cancel()` Attempts to cancel the execution if both the XQuery engine and XQJ driver support aborting the execution of an `XQPreparedExpression`.
`XQResultSequence` `executeQuery()` Executes the prepared query expression.
`protected boolean` `externalVariableExists(QName name)`
`QName[]` `getAllExternalVariables()` Retrieves all the external variables defined in the prolog of the prepared expression.
`QName[]` `getAllUnboundExternalVariables()` Retrieves the names of all unbound external variables.
`protected SaxonXQConnection` `getConnection()`
`protected SaxonXQDataFactory` `getDataFactory()`
`protected DynamicQueryContext` `getDynamicContext()`
`protected SaxonXQStaticContext` `getSaxonXQStaticContext()`
`XQStaticContext` `getStaticContext()` Gets an `XQStaticContext` representing the values for all expression properties.
`XQSequenceType` `getStaticResultType()` Gets the static type information of the result sequence.
`XQSequenceType` `getStaticVariableType(QName name)` Retrieves the static type of a given external variable.
`protected XQueryExpression` `getXQueryExpression()`

Methods inherited from class net.sf.saxon.xqj.SaxonXQDynamicContext
`bindAtomicValue, bindBoolean, bindByte, bindDocument, bindDocument, bindDocument, bindDocument, bindDocument, bindDouble, bindFloat, bindInt, bindItem, bindLong, bindNode, bindObject, bindSequence, bindShort, bindString, getConfiguration, getImplicitTimeZone, setImplicitTimeZone`

Methods inherited from class net.sf.saxon.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.XQPreparedExpression
`close, isClosed`

Methods inherited from interface javax.xml.xquery.XQDynamicContext
`bindAtomicValue, bindBoolean, bindByte, bindDocument, bindDocument, bindDocument, bindDocument, bindDocument, bindDouble, bindFloat, bindInt, bindItem, bindLong, bindNode, bindObject, bindSequence, bindShort, bindString, getImplicitTimeZone, setImplicitTimeZone`

Constructor Detail

### SaxonXQPreparedExpression

    protected SaxonXQPreparedExpression(SaxonXQConnection connection,
                                        XQueryExpression expression,
                                        SaxonXQStaticContext sqc,
                                        DynamicQueryContext context)
                                 throws XQException

Throws:
  `XQException`

Method Detail

### getDynamicContext

    protected DynamicQueryContext getDynamicContext()

  Specified by:
    `getDynamicContext` in class `SaxonXQDynamicContext`

### getConnection

    protected SaxonXQConnection getConnection()

### getDataFactory

    protected SaxonXQDataFactory getDataFactory()
                                         throws XQException

  Specified by:
    `getDataFactory` in class `SaxonXQDynamicContext`
  Throws:
    `XQException`

### getXQueryExpression

    protected XQueryExpression getXQueryExpression()

### getSaxonXQStaticContext

    protected SaxonXQStaticContext getSaxonXQStaticContext()

### cancel

    public void cancel()
                throws XQException

  Description copied from interface: `XQPreparedExpression`
  Attempts to cancel the execution if both the XQuery engine and XQJ driver support aborting the execution of an `XQPreparedExpression`. This method can be used by one thread to cancel an `XQPreparedExpression`, that is being executed in another thread. If cancellation is not supported or the attempt to cancel the execution was not successful, the method returns without any error. If the cancellation is successful, an `XQException` is thrown, to indicate that it has been aborted, by `executeQuery`, `executeCommand` or any method accessing the `XQResultSequence` returned by `executeQuery`. If applicable, any open `XQResultSequence` and `XQResultItem` objects will also be implicitly closed in this case.

  Specified by:
    `cancel` in interface `XQPreparedExpression`
  Throws:
    `XQException` - if the prepared expression is in a closed state

### executeQuery

    public XQResultSequence executeQuery()
                                  throws XQException

  Description copied from interface: `XQPreparedExpression`
  Executes the prepared query expression. Calling this method implicitly closes any previous result sequence obtained from this expression.

  Specified by:
    `executeQuery` in interface `XQPreparedExpression`
  Returns:
    the xquery sequence object containing the result of the query execution
  Throws:
    `XQException` - if (1) there are errors when executing the prepared expression, (2) the prepared expression is in a closed state, or (3) the query execution is cancelled

### getAllExternalVariables

    public QName[] getAllExternalVariables()
                                    throws XQException

  Description copied from interface: `XQPreparedExpression`
  Retrieves all the external variables defined in the prolog of the prepared expression.

  Specified by:
    `getAllExternalVariables` in interface `XQPreparedExpression`
  Returns:
    an array of `QName` objects for all the external variables defined in the prolog of a prepared expression. Empty array if there are no external variables present.
  Throws:
    `XQException` - if the prepared expression is in a closed state

### getAllUnboundExternalVariables

    public QName[] getAllUnboundExternalVariables()
                                           throws XQException

  Description copied from interface: `XQPreparedExpression`
  Retrieves the names of all unbound external variables.

  Specified by:
    `getAllUnboundExternalVariables` in interface `XQPreparedExpression`
  Returns:
    the `QName` for all the external variables defined in the prolog of a prepared expression that are yet to be bound with a value. If there are no such variables an empty array is returned
  Throws:
    `XQException` - if the prepared expression is in a closed state

### getStaticContext

    public XQStaticContext getStaticContext()
                                     throws XQException

  Description copied from interface: `XQPreparedExpression`
  Gets an `XQStaticContext` representing the values for all expression properties. Note that these properties cannot be changed; in order to change, a new `XQPreparedExpression` needs to be created.

  Specified by:
    `getStaticContext` in interface `XQPreparedExpression`
  Returns:
    an `XQStaticContext` representing the values for all expression properties
  Throws:
    `XQException` - if the expression is in a closed state

### getStaticResultType

    public XQSequenceType getStaticResultType()
                                       throws XQException

  Description copied from interface: `XQPreparedExpression`
  Gets the static type information of the result sequence. If an implementation does not do static typing of the query, then this method must return an `XQSequenceType` object corresponding to the XQuery sequence type `item()*`.

  Specified by:
    `getStaticResultType` in interface `XQPreparedExpression`
  Returns:
    `XQSequenceType` containing the static result information.
  Throws:
    `XQException` - if the prepared expression is in a closed state

### getStaticVariableType

    public XQSequenceType getStaticVariableType(QName name)
                                         throws XQException

  Description copied from interface: `XQPreparedExpression`
  Retrieves the static type of a given external variable.

  Specified by:
    `getStaticVariableType` in interface `XQPreparedExpression`
  Parameters:
    `name` - the name of the external variable
  Returns:
    the static type information of the variable as defined in the prolog of the prepared expression
  Throws:
    `XQException` - if (1) the variable does not exist in the static context of the expression, or (2) the sequence is in a closed state, or (3) the `name` parameter is `null`

### externalVariableExists

    protected boolean externalVariableExists(QName name)

  Specified by:
    `externalVariableExists` in class `SaxonXQDynamicContext`

Copyright (c) 2004-2010 Saxonica Limited. All rights reserved.