no.sesat.search.query.token
Class AbstractEvaluatorFactory

java.lang.Object
  no.sesat.search.query.token.AbstractEvaluatorFactory

Direct Known Subclasses:

FastQueryMatchingEvaluatorFactory, JepEvaluatorFactory, RegExpEvaluatorFactory, SolrEvaluatorFactory

public abstract class AbstractEvaluatorFactory
extends Object

EvaluatorFactory responsible to finding appropriate factory subclass to use given the context. Any implementing EvaluatorFactory provides two main methods isResponsibleFor(token) getEvaluator(token) which are used by primarily by the TokenEvaluationEngine to find applicable evaluators and to use them. SKER3540

Version:

$Id: AbstractEvaluatorFactory.java 7225 2009-04-09 00:32:20Z ssmiweve $

Nested Class Summary

static interface

AbstractEvaluatorFactory.Context The context the RegExpEvaluatorFactory must work against.

Constructor Summary

protected

AbstractEvaluatorFactory(AbstractEvaluatorFactory.Context context) All factory implementations must super to this in their constructor.

Method Summary

protected AbstractEvaluatorFactory.Context	getContext() Obtain the context we're working within.
abstract TokenEvaluator	getEvaluator(TokenPredicate token) If the evaluator is not found in this site it will fallback and look in the parent site.
static AbstractEvaluatorFactory	instanceOf(AbstractEvaluatorFactory.Context cxt) find the appropriate factory subclass to use given the context.
boolean	isResponsibleFor(TokenPredicate token) Is the factory responsibe for evaluation of this TokenPredicate.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractEvaluatorFactory

protected AbstractEvaluatorFactory(AbstractEvaluatorFactory.Context context)
                            throws SiteKeyedFactoryInstantiationException

All factory implementations must super to this in their constructor.

Parameters:

context - the supplied context to work within.

Throws:

SiteKeyedFactoryInstantiationException - if factory construction fails.

Method Detail

instanceOf

public static final AbstractEvaluatorFactory instanceOf(AbstractEvaluatorFactory.Context cxt)

find the appropriate factory subclass to use given the context.

Parameters:

cxt - supplied context.

Returns:

the appropriate factory subclass.

isResponsibleFor

public boolean isResponsibleFor(TokenPredicate token)

Is the factory responsibe for evaluation of this TokenPredicate. Default implementation checks that getEvaluator(..) does not return ALWAYS_FALSE_EVALUATOR

Parameters:

token - the TokenPredicate we're checking

Returns:

true if factory is responsible for evaluating the given TokenPredicate.

getEvaluator

public abstract TokenEvaluator getEvaluator(TokenPredicate token)
                                     throws EvaluationException

If the evaluator is not found in this site it will fallback and look in the parent site.

Parameters:

token - the predicate the evaluator is to be used for

Returns:

the TokenEvaluator to use. Or TokenEvaluationEngineImpl.ALWAYS_FALSE_EVALUATOR if not found.

Throws:

EvaluationException

getContext

protected final AbstractEvaluatorFactory.Context getContext()

Obtain the context we're working within.

Returns:

the context.