net.sf.saxon.xqj
Class SaxonXQPreparedExpression

java.lang.Object
  extended by net.sf.saxon.xqj.Closable
      extended by net.sf.saxon.xqj.SaxonXQDynamicContext
          extended by 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.