Class HTTPBooleanQuery

java.lang.Object

org.eclipse.rdf4j.query.impl.AbstractOperation

org.eclipse.rdf4j.query.impl.AbstractQuery

org.eclipse.rdf4j.http.client.query.AbstractHTTPQuery

org.eclipse.rdf4j.repository.http.HTTPBooleanQuery

All Implemented Interfaces:

BooleanQuery, Operation, Query

public class HTTPBooleanQuery
extends AbstractHTTPQuery
implements BooleanQuery

TupleQuery specific to the HTTP protocol. Methods in this class may throw the specific RepositoryException subclass UnautorizedException, the semantics of which is defined by the HTTP protocol.

Author:

Arjohn Kampman

See Also:

• UnauthorizedException

Nested Class Summary

Nested classes/interfaces inherited from interface Query

Query.QueryType

Modifier and Type	Interface	Description
static enum	Query.QueryType	The different types of queries that RDF4J recognizes: boolean queries, graph queries, and tuple queries.

Field Summary

Fields inherited from class AbstractHTTPQuery

baseURI, queryLanguage, queryString

Modifier and Type	Field	Description
protected final String	baseURI
protected final QueryLanguage	queryLanguage
protected final String	queryString

Fields inherited from class AbstractOperation

bindings, dataset, includeInferred

Modifier and Type	Field	Description
protected final MapBindingSet	bindings
protected Dataset	dataset
protected boolean	includeInferred

Constructor Summary

Constructors

Constructor	Description
HTTPBooleanQuery(org.eclipse.rdf4j.repository.http.HTTPRepositoryConnection conn, QueryLanguage ql, String queryString, String baseURI)

Method Summary

Modifier and Type	Method	Description
boolean	evaluate()
Explanation	explain(Explanation.Level level)	Explain how the query will be (or has been) executed/evaluated by returning an explanation of the query plan.

Methods inherited from class AbstractHTTPQuery

getBindingsArray, getHttpClient, setMaxExecutionTime, toString

Modifier and Type	Method	Description
Binding[]	getBindingsArray()
protected SPARQLProtocolSession	getHttpClient()
void	setMaxExecutionTime(int maxExecutionTimeSeconds)	Specifies the maximum time that an operation is allowed to run.
String	toString()

Methods inherited from class AbstractQuery

getMaxQueryTime, setMaxQueryTime

Modifier and Type	Method	Description
int	getMaxQueryTime()	Deprecated.
void	setMaxQueryTime(int maxQueryTimeSeconds)	Deprecated.

Methods inherited from class AbstractOperation

clearBindings, getBindings, getDataset, getIncludeInferred, getMaxExecutionTime, removeBinding, setBinding, setDataset, setIncludeInferred

Modifier and Type	Method	Description
void	clearBindings()	Removes all previously set bindings.
BindingSet	getBindings()	Retrieves the bindings that have been set on this operation.
Dataset	getDataset()	Gets the dataset that has been set using Operation.setDataset(Dataset), if any.
boolean	getIncludeInferred()	Returns whether or not this operation will return inferred statements (if any are present in the repository).
int	getMaxExecutionTime()	Returns the maximum operation execution time.
void	removeBinding(String name)	Removes a previously set binding on the supplied variable.
void	setBinding(String name, Value value)	Binds the specified variable to the supplied value.
void	setDataset(Dataset dataset)	Specifies the dataset against which to execute an operation, overriding any dataset that is specified in the operation itself.
void	setIncludeInferred(boolean includeInferred)	Determine whether evaluation results of this operation should include inferred statements (if any inferred statements are present in the repository).

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

HTTPBooleanQuery

public HTTPBooleanQuery(org.eclipse.rdf4j.repository.http.HTTPRepositoryConnection conn,
 QueryLanguage ql,
 String queryString,
 String baseURI)

Method Details

evaluate

public boolean evaluate()
                 throws QueryEvaluationException

Specified by:

evaluate in interface BooleanQuery

Throws:

QueryEvaluationException

explain

public Explanation explain(Explanation.Level level)

Description copied from interface: Query

Explain how the query will be (or has been) executed/evaluated by returning an explanation of the query plan.

This method is useful for understanding why a particular query is slow. The most useful level is Executed, but this takes as long as it takes to execute/evaluate the query.

When timing a query you should keep in mind that the query performance will vary based on how much the JIT compiler has compiled the code (C1 vs C2) and based on what is or isn't cached in memory. If Timed explanations are considerably slower than Executed explanations the overhead with timing the query may be large on your system and should not be trusted.

WARNING: This method is experimental and is subject to change or removal without warning. Same goes for the returned explanation. There is currently only partial support for this method in RDF4J and and UnsupportedOperationException where support is lacking.

Specified by:

explain in interface Query

Parameters:

level - The explanation level that should be used to create the explanation. Choose between: Unoptimized (as parsed without optimizations) , Optimized (as is actually going to be used), Executed (as was executed/evaluated with actual result sizes), Telemetry (as was executed/evaluated, including runtime telemetry metrics), Timed (as was executed/evaluated including timing for each plan node). Executed, Telemetry and Timed levels can potentially be slow.

Returns:

The explanation that we generated, which can be viewed in a human readable format with toString(), as JSON or as a simplified query plan object structure.