com.hp.hpl.jena.rdql
Class QueryResultsStream

java.lang.Object
  com.hp.hpl.jena.rdql.QueryResultsStream

All Implemented Interfaces:

QueryResults, Iterator

public class QueryResultsStream
extends Object
implements QueryResults

The main QueryResults implementation for returning results from queries. This version is "use once" - you can not reset the result set because the resulys of the query are not remembered so as not to consume potentially large amounts of memory.

Version:

$Id: QueryResultsStream.java,v 1.7 2004/05/28 16:56:15 andy_seaborne Exp $

Author:

Andy Seaborne

See Also:

Query, QueryEngine, ResultBindingImpl, QueryResultsStream

Constructor Summary

QueryResultsStream(Query query, QueryExecution qe, Iterator iter)

Method Summary

void	close() Close the results iterator and stop query evaluation as soon as convenient.
List	getAll() Deprecated. QueryResultsStream do not have all the results at once - QueryResultsMem
String	getBinding(String name) Access a binding (a mapping from variable name to value).
List	getResultVars() Get the variable names for the projection
int	getRowNumber() Return the "row number" - a count of the number of possibilities returned so far.
boolean	hasNext() Is there another possibility?
Object	next() Moves onto the next result possibility.
void	remove()

Methods inherited from class java.lang.Object

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

Constructor Detail

QueryResultsStream

public QueryResultsStream(Query query,
                          QueryExecution qe,
                          Iterator iter)

Method Detail

remove

public void remove()
            throws UnsupportedOperationException

Specified by:

remove in interface QueryResults

Specified by:

remove in interface Iterator

Throws:

UnsupportedOperationException - Always thrown.

hasNext

public boolean hasNext()

Is there another possibility?

Specified by:

hasNext in interface QueryResults

Specified by:

hasNext in interface Iterator

next

public Object next()

Moves onto the next result possibility. The returned object is actual the binding for this result; it is possible to access the bound variables for the current possibility through the additional variable accessor opertations.

Specified by:

next in interface QueryResults

Specified by:

next in interface Iterator

close

public void close()

Close the results iterator and stop query evaluation as soon as convenient.

Specified by:

close in interface QueryResults

getBinding

public String getBinding(String name)

Access a binding (a mapping from variable name to value). RDF does not explicitly type values so we only provide a string form and leave it to the application context to interpret as an integer, date etc.

getRowNumber

public int getRowNumber()

Return the "row number" - a count of the number of possibilities returned so far. Remains valid (as the total number of possibilities) after the iterator ends.

Specified by:

getRowNumber in interface QueryResults

getResultVars

public List getResultVars()

Get the variable names for the projection

Specified by:

getResultVars in interface QueryResults

getAll

public List getAll()

Deprecated. QueryResultsStream do not have all the results at once - QueryResultsMem

Convenience function to consume a query. Returns a list of ResultBindingImpls.

Specified by:

getAll in interface QueryResults

Returns:

List