Package cz.cvut.kbss.jopa.model

Class QueryHintsHandler

java.lang.Object

cz.cvut.kbss.jopa.model.QueryHintsHandler

public class QueryHintsHandler
extends Object

Processes query hints.

To add a new hint (inspired by Eclipselink):

• Define a hint in QueryHints
• Ad an inner class extending QueryHintsHandler.Hint corresponding to the new hint. The class should implement the QueryHintsHandler.Hint.applyToQuery(Object, AbstractQuery, Statement) method and provide an array of values for transformation.
• Register the new hint class by calling QueryHintsHandler.Hint.registerHint(Hint) with an instance of the hint

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	QueryHintsHandler.DisableInferenceHint	Allows disabling inference for query execution.
protected static class	QueryHintsHandler.TargetOntologyHint

Method Summary

Modifier and Type	Method	Description
static void	apply(String hintName, Object hintValue, cz.cvut.kbss.jopa.model.AbstractQuery query, Statement statement)	Applies the specified hint value to the specified query.
static Set<String>	getSupportedHints()	Gets query hints supported by this implementation.

Methods inherited from class java.lang.Object

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

Method Details

getSupportedHints

public static Set<String> getSupportedHints()

Gets query hints supported by this implementation.

Returns:

A set of query hint names

apply

public static void apply(String hintName,
 Object hintValue,
 cz.cvut.kbss.jopa.model.AbstractQuery query,
 Statement statement)

Applies the specified hint value to the specified query.

Note that if the hint is unknown, it is ignored.

Parameters:

hintName - Query hint name

hintValue - Query hint value

query - Query to apply the hint value to

statement - OntoDriver statement that will be used to execute the specified query. The hint value may be applied directly to it

Throws:

IllegalArgumentException - If the hint value is not supported