Module org.apache.jena.arq

Package org.apache.jena.sparql.exec

Class QueryExecutionCompat

java.lang.Object

org.apache.jena.sparql.exec.QueryExecutionAdapter

org.apache.jena.sparql.exec.QueryExecutionCompat

All Implemented Interfaces:

AutoCloseable, QueryExecution

public class QueryExecutionCompat
extends QueryExecutionAdapter

Query execution that delays making the QueryExecution until needed by exec This means timeout and initialBindings can still be set.

See Also:

• QueryExecution

Method Summary

Modifier and Type	Method	Description
void	abort()	Stop in mid execution.
void	close()	Close the query execution and stop query evaluation as soon as convenient.
static QueryExecution	compatibility(QueryExecMod qExec, Dataset dataset, Query query, String queryString)
boolean	execAsk()	Execute an ASK query
Model	execConstruct()	Execute a CONSTRUCT query
Model	execConstruct(Model model)	Execute a CONSTRUCT query, putting the statements into a graph.
Dataset	execConstructDataset()	Execute a CONSTRUCT query, putting the statements into 'dataset'.
Dataset	execConstructDataset(Dataset dataset)	Execute a CONSTRUCT query, putting the statements into 'dataset'.
Iterator<Quad>	execConstructQuads()	Execute a CONSTRUCT query, returning the results as an iterator of Quad.
Iterator<Triple>	execConstructTriples()	Execute a CONSTRUCT query, returning the results as an iterator of Triple.
Model	execDescribe()	Execute a DESCRIBE query
Model	execDescribe(Model model)	Execute a DESCRIBE query, putting the statements into a graph.
Iterator<Triple>	execDescribeTriples()	Execute a DESCRIBE query, returning the results as an iterator of Triple.
JsonArray	execJson()	Execute a JSON query and return a json array
Iterator<JsonObject>	execJsonItems()	Execute a JSON query and return an iterator
ResultSet	execSelect()	Execute a SELECT query
Context	getContext()	The properties associated with a query execution - implementation specific parameters This includes Java objects (so it is not an RDF graph).
Dataset	getDataset()	The dataset against which the query will execute.
Query	getQuery()	The query associated with a query execution.
long	getTimeout1()	Return the first timeout (time to first result), in milliseconds: negative if unset
long	getTimeout2()	Return the second timeout (overall query execution after first result), in milliseconds: negative if unset
boolean	isClosed()	Answer whether this QueryExecution object has been closed or not.
void	setInitialBinding(QuerySolution querySolution)	Set the initial association of variables and values.
void	setInitialBinding(Binding binding)	Set the initial association of variables and values.
void	setTimeout(long timeout)	Set time, in milliseconds
void	setTimeout(long timeout1, long timeout2)	Set time, in milliseconds
void	setTimeout(long timeout, TimeUnit timeoutUnits)	Set a timeout on the query execution.
void	setTimeout(long timeout1, TimeUnit timeUnit1, long timeout2, TimeUnit timeUnit2)	Set timeouts on the query execution; the first timeout refers to time to first result, the second refers to overall query execution after the first result.

Methods inherited from class org.apache.jena.sparql.exec.QueryExecutionAdapter

adapt, getQueryString

Methods inherited from class java.lang.Object

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

Method Details

compatibility

public static QueryExecution compatibility(QueryExecMod qExec,
 Dataset dataset,
 Query query,
 String queryString)

setInitialBinding

public void setInitialBinding(Binding binding)

Description copied from class: QueryExecutionAdapter

Set the initial association of variables and values. May not be supported by all QueryExecution implementations.

Specified by:

setInitialBinding in interface QueryExecution

Overrides:

setInitialBinding in class QueryExecutionAdapter

getDataset

public Dataset getDataset()

Description copied from class: QueryExecutionAdapter

The dataset against which the query will execute. May be null, implying it is expected that the query itself has a dataset description.

Specified by:

getDataset in interface QueryExecution

Overrides:

getDataset in class QueryExecutionAdapter

getContext

public Context getContext()

Description copied from class: QueryExecutionAdapter

The properties associated with a query execution - implementation specific parameters This includes Java objects (so it is not an RDF graph). Keys should be URIs as strings. May be null (this implementation does not provide any configuration).

Specified by:

getContext in interface QueryExecution

Overrides:

getContext in class QueryExecutionAdapter

getQuery

public Query getQuery()

Description copied from class: QueryExecutionAdapter

The query associated with a query execution. May be null (QueryExecution may have been created by other means)

Specified by:

getQuery in interface QueryExecution

Overrides:

getQuery in class QueryExecutionAdapter

execSelect

public ResultSet execSelect()

Description copied from class: QueryExecutionAdapter

Execute a SELECT query

Important: The name of this method is somewhat of a misnomer in that depending on the underlying implementation this typically does not execute the SELECT query but rather answers a wrapper over an internal data structure that can be used to answer the query. In essence calling this method only returns a plan for executing this query which only gets evaluated when you actually start iterating over the results.

Specified by:

execSelect in interface QueryExecution

Overrides:

execSelect in class QueryExecutionAdapter

execConstruct

public Model execConstruct()

Description copied from class: QueryExecutionAdapter

Execute a CONSTRUCT query

Specified by:

execConstruct in interface QueryExecution

Overrides:

execConstruct in class QueryExecutionAdapter

execConstruct

public Model execConstruct(Model model)

Description copied from class: QueryExecutionAdapter

Execute a CONSTRUCT query, putting the statements into a graph.

Specified by:

execConstruct in interface QueryExecution

Overrides:

execConstruct in class QueryExecutionAdapter

Returns:

Graph The model argument for cascaded code.

execConstructTriples

public Iterator<Triple> execConstructTriples()

Description copied from class: QueryExecutionAdapter

Execute a CONSTRUCT query, returning the results as an iterator of Triple.

Caution: This method may return duplicate Triples. This method may be useful if you only need the results for stream processing, as it can avoid having to place the results in a Model.

Important: The name of this method is somewhat of a misnomer in that depending on the underlying implementation this typically does not execute the CONSTRUCT query but rather answers a wrapper over an internal data structure that can be used to answer the query. In essence calling this method only returns a plan for executing this query which only gets evaluated when you actually start iterating over the results.

Specified by:

execConstructTriples in interface QueryExecution

Overrides:

execConstructTriples in class QueryExecutionAdapter

Returns:

An iterator of Triple objects (possibly containing duplicates) generated by applying the CONSTRUCT template of the query to the bindings in the WHERE clause.

execConstructQuads

public Iterator<Quad> execConstructQuads()

Description copied from class: QueryExecutionAdapter

Execute a CONSTRUCT query, returning the results as an iterator of Quad.

Caution: This method may return duplicate Quads. This method may be useful if you only need the results for stream processing, as it can avoid having to place the results in a Model.

An iterator of Quad objects (possibly containing duplicates) generated by applying the CONSTRUCT template of the query to the bindings in the WHERE clause.

See QueryExecutionAdapter.execConstructTriples() for usage and features.

Specified by:

execConstructQuads in interface QueryExecution

Overrides:

execConstructQuads in class QueryExecutionAdapter

Returns:

An iterator of Quad objects (possibly containing duplicates) generated by applying the CONSTRUCT template of the query to the bindings in the WHERE clause.

execConstructDataset

public Dataset execConstructDataset()

Description copied from class: QueryExecutionAdapter

Execute a CONSTRUCT query, putting the statements into 'dataset'. This maybe an extended syntax query (if supported).

Specified by:

execConstructDataset in interface QueryExecution

Overrides:

execConstructDataset in class QueryExecutionAdapter

execConstructDataset

public Dataset execConstructDataset(Dataset dataset)

Description copied from class: QueryExecutionAdapter

Execute a CONSTRUCT query, putting the statements into 'dataset'. This may be an extended syntax query (if supported).

Specified by:

execConstructDataset in interface QueryExecution

Overrides:

execConstructDataset in class QueryExecutionAdapter

execDescribe

public Model execDescribe()

Description copied from class: QueryExecutionAdapter

Execute a DESCRIBE query

Specified by:

execDescribe in interface QueryExecution

Overrides:

execDescribe in class QueryExecutionAdapter

execDescribe

public Model execDescribe(Model model)

Description copied from class: QueryExecutionAdapter

Execute a DESCRIBE query, putting the statements into a graph.

Specified by:

execDescribe in interface QueryExecution

Overrides:

execDescribe in class QueryExecutionAdapter

Returns:

Graph The model argument for cascaded code.

execDescribeTriples

public Iterator<Triple> execDescribeTriples()

Description copied from class: QueryExecutionAdapter

Execute a DESCRIBE query, returning the results as an iterator of Triple.

Caution: This method may return duplicate Triples. This method may be useful if you only need the results for stream processing, as it can avoid having to place the results in a Model.

Important: The name of this method is somewhat of a misnomer in that depending on the underlying implementation this typically does not execute the DESCRIBE query but rather answers a wrapper over an internal data structure that can be used to answer the query. In essence calling this method only returns a plan for executing this query which only gets evaluated when you actually start iterating over the results.

Specified by:

execDescribeTriples in interface QueryExecution

Overrides:

execDescribeTriples in class QueryExecutionAdapter

Returns:

An iterator of Triple objects (possibly containing duplicates) generated as the output of the DESCRIBE query.

execAsk

public boolean execAsk()

Description copied from class: QueryExecutionAdapter

Execute an ASK query

Specified by:

execAsk in interface QueryExecution

Overrides:

execAsk in class QueryExecutionAdapter

execJson

public JsonArray execJson()

Description copied from class: QueryExecutionAdapter

Execute a JSON query and return a json array

Specified by:

execJson in interface QueryExecution

Overrides:

execJson in class QueryExecutionAdapter

execJsonItems

public Iterator<JsonObject> execJsonItems()

Description copied from class: QueryExecutionAdapter

Execute a JSON query and return an iterator

Specified by:

execJsonItems in interface QueryExecution

Overrides:

execJsonItems in class QueryExecutionAdapter

abort

public void abort()

Description copied from class: QueryExecutionAdapter

Stop in mid execution. This method can be called in parallel with other methods on the QueryExecution object. There is no guarantee that the concrete implementation actual will stop or that it will do so immediately. No operations on the query execution or any associated result set are permitted after this call and may cause exceptions to be thrown.

Specified by:

abort in interface QueryExecution

Overrides:

abort in class QueryExecutionAdapter

close

public void close()

Description copied from class: QueryExecutionAdapter

Close the query execution and stop query evaluation as soon as convenient. QueryExecution objects, and a ResultSet from QueryExecutionAdapter.execSelect(), can not be used once the QueryExecution is closed. Model results from QueryExecutionAdapter.execConstruct() and QueryExecutionAdapter.execDescribe() are still valid. It is important to close query execution objects in order to release resources such as working memory and to stop the query execution. Some storage subsystems require explicit ends of operations and this operation will cause those to be called where necessary. No operations on the query execution or any associated result set are permitted after this call.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface QueryExecution

Overrides:

close in class QueryExecutionAdapter

isClosed

public boolean isClosed()

Description copied from class: QueryExecutionAdapter

Answer whether this QueryExecution object has been closed or not.

Specified by:

isClosed in interface QueryExecution

Overrides:

isClosed in class QueryExecutionAdapter

Returns:

boolean

setTimeout

public void setTimeout(long timeout,
 TimeUnit timeoutUnits)

Description copied from class: QueryExecutionAdapter

Set a timeout on the query execution. Processing will be aborted after the timeout (which starts when the appropriate exec call is made). Not all query execution systems support timeouts. A timeout of less than zero means no timeout.

Specified by:

setTimeout in interface QueryExecution

Overrides:

setTimeout in class QueryExecutionAdapter

See Also:

• QueryExecutionDatasetBuilder.timeout(long, java.util.concurrent.TimeUnit)

setTimeout

public void setTimeout(long timeout)

Description copied from class: QueryExecutionAdapter

Set time, in milliseconds

Specified by:

setTimeout in interface QueryExecution

Overrides:

setTimeout in class QueryExecutionAdapter

See Also:

• QueryExecutionAdapter.setTimeout(long, TimeUnit)

setTimeout

public void setTimeout(long timeout1,
 TimeUnit timeUnit1,
 long timeout2,
 TimeUnit timeUnit2)

Description copied from class: QueryExecutionAdapter

Set timeouts on the query execution; the first timeout refers to time to first result, the second refers to overall query execution after the first result. Processing will be aborted if a timeout expires. Not all query execution systems support timeouts. A timeout of less than zero means no timeout; this can be used for timeout1 or timeout2.

Specified by:

setTimeout in interface QueryExecution

Overrides:

setTimeout in class QueryExecutionAdapter

setTimeout

public void setTimeout(long timeout1,
 long timeout2)

Description copied from class: QueryExecutionAdapter

Set time, in milliseconds

Specified by:

setTimeout in interface QueryExecution

Overrides:

setTimeout in class QueryExecutionAdapter

See Also:

• QueryExecutionAdapter.setTimeout(long, TimeUnit, long, TimeUnit)

getTimeout1

public long getTimeout1()

Description copied from class: QueryExecutionAdapter

Return the first timeout (time to first result), in milliseconds: negative if unset

Specified by:

getTimeout1 in interface QueryExecution

Overrides:

getTimeout1 in class QueryExecutionAdapter

getTimeout2

public long getTimeout2()

Description copied from class: QueryExecutionAdapter

Return the second timeout (overall query execution after first result), in milliseconds: negative if unset

Specified by:

getTimeout2 in interface QueryExecution

Overrides:

getTimeout2 in class QueryExecutionAdapter

setInitialBinding

public void setInitialBinding(QuerySolution querySolution)

Description copied from interface: QueryExecution

Set the initial association of variables and values. May not be supported by all QueryExecution implementations.

The preferred way is to use QueryExecutionDatasetBuilder.substitution(QuerySolution) which is supported uniformly for local and remote queries.

Specified by:

setInitialBinding in interface QueryExecution

Overrides:

setInitialBinding in class QueryExecutionAdapter