Package org.apache.lucene.analysis

Class AnalysisSPILoader<S extends AbstractAnalysisFactory>

java.lang.Object

org.apache.lucene.analysis.AnalysisSPILoader<S>

public final class AnalysisSPILoader<S extends AbstractAnalysisFactory>
extends Object

Helper class for loading named SPIs from classpath (e.g. Tokenizers, TokenStreams).

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Constructor Summary

Constructors

Constructor	Description
AnalysisSPILoader(Class<S> clazz)
AnalysisSPILoader(Class<S> clazz, ClassLoader classloader)

Method Summary

Modifier and Type	Method	Description
Set<String>	availableServices()
Class<? extends S>	lookupClass(String name)
static String	lookupSPIName(Class<? extends AbstractAnalysisFactory> service)	Looks up SPI name (static "NAME" field) with appropriate modifiers.
static <T extends AbstractAnalysisFactory> T	newFactoryClassInstance(Class<T> clazz, Map<String,String> args)	Creates a new instance of the given AbstractAnalysisFactory by invoking the constructor, passing the given argument map.
S	newInstance(String name, Map<String,String> args)
void	reload(ClassLoader classloader)	Reloads the internal SPI list from the given ClassLoader.

Methods inherited from class java.lang.Object

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

Constructor Detail

AnalysisSPILoader

public AnalysisSPILoader(Class<S> clazz)

AnalysisSPILoader

public AnalysisSPILoader(Class<S> clazz,
                         ClassLoader classloader)

Method Detail

reload

public void reload(ClassLoader classloader)

Reloads the internal SPI list from the given ClassLoader. Changes to the service list are visible after the method ends, all iterators (e.g., from availableServices(),...) stay consistent.

NOTE: Only new service providers are added, existing ones are never removed or replaced.

This method is expensive and should only be called for discovery of new service providers on the given classpath/classloader!

newInstance

public S newInstance(String name,
                     Map<String,String> args)

lookupClass

public Class<? extends S> lookupClass(String name)

availableServices

public Set<String> availableServices()

lookupSPIName

public static String lookupSPIName(Class<? extends AbstractAnalysisFactory> service)
                            throws NoSuchFieldException,
                                   IllegalAccessException,
                                   IllegalStateException

Looks up SPI name (static "NAME" field) with appropriate modifiers. Also it must be a String class and declared in the concrete class.

Returns:

the SPI name

Throws:

NoSuchFieldException - - if the "NAME" field is not defined.

IllegalAccessException - - if the "NAME" field is inaccessible.

IllegalStateException - - if the "NAME" field does not have appropriate modifiers or isn't a String field.

newFactoryClassInstance

public static <T extends AbstractAnalysisFactory> T newFactoryClassInstance(Class<T> clazz,
                                                                            Map<String,String> args)

Creates a new instance of the given AbstractAnalysisFactory by invoking the constructor, passing the given argument map.