| /******************************************************************************* |
| * Copyright (c) 2010, 2013 Sonatype, Inc. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * Stuart McCulloch (Sonatype, Inc.) - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.sisu.plexus; |
| |
| import java.util.Collection; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Map.Entry; |
| import java.util.Set; |
| |
| import javax.inject.Provider; |
| |
| import org.codehaus.plexus.component.annotations.Requirement; |
| import org.eclipse.sisu.bean.BeanProperty; |
| import org.eclipse.sisu.wire.EntryListAdapter; |
| import org.eclipse.sisu.wire.EntryMapAdapter; |
| import org.eclipse.sisu.wire.EntrySetAdapter; |
| |
| import com.google.inject.ProvisionException; |
| import com.google.inject.TypeLiteral; |
| import com.google.inject.spi.TypeEncounter; |
| |
| /** |
| * Creates {@link Provider}s for properties with @{@link Requirement} metadata. |
| */ |
| final class PlexusRequirements |
| { |
| // ---------------------------------------------------------------------- |
| // Implementation fields |
| // ---------------------------------------------------------------------- |
| |
| private final Provider<PlexusBeanLocator> locatorProvider; |
| |
| // ---------------------------------------------------------------------- |
| // Constructors |
| // ---------------------------------------------------------------------- |
| |
| PlexusRequirements( final TypeEncounter<?> encounter ) |
| { |
| locatorProvider = encounter.getProvider( PlexusBeanLocator.class ); |
| } |
| |
| // ---------------------------------------------------------------------- |
| // Public methods |
| // ---------------------------------------------------------------------- |
| |
| /** |
| * Creates a {@link Provider} that provides Plexus components that match the given property requirement. |
| * |
| * @param requirement The Plexus requirement |
| * @param property The bean property |
| * @return Provider that provides required Plexus components for the given property |
| */ |
| @SuppressWarnings( { "unchecked", "rawtypes" } ) |
| public <T> Provider<T> lookup( final Requirement requirement, final BeanProperty<T> property ) |
| { |
| try |
| { |
| // deduce lookup from metadata + property details |
| final TypeLiteral<T> expectedType = property.getType(); |
| final TypeLiteral<T> roleType = (TypeLiteral<T>) Roles.roleType( requirement, expectedType ); |
| final Class<?> rawType = expectedType.getRawType(); |
| |
| final String[] hints = Hints.canonicalHints( requirement ); |
| |
| if ( Map.class == rawType ) |
| { |
| return new RequirementMapProvider( locatorProvider, roleType, hints ); |
| } |
| else if ( List.class == rawType || Collection.class == rawType || Iterable.class == rawType ) |
| { |
| return new RequirementListProvider( locatorProvider, roleType, hints ); |
| } |
| else if ( Set.class == rawType ) |
| { |
| return new RequirementSetProvider( locatorProvider, roleType, hints ); |
| } |
| |
| return new RequirementProvider( locatorProvider, roleType, hints ); |
| } |
| catch ( final RuntimeException e ) |
| { |
| // defer until later... |
| return new Provider<T>() |
| { |
| public T get() |
| { |
| throw new ProvisionException( "Error in requirement: " + property, e ); |
| } |
| }; |
| } |
| } |
| |
| // ---------------------------------------------------------------------- |
| // Implementation types |
| // ---------------------------------------------------------------------- |
| |
| /** |
| * Abstract {@link Provider} that locates Plexus beans on-demand. |
| */ |
| private static abstract class AbstractRequirementProvider<S, T> |
| implements Provider<S> |
| { |
| // ---------------------------------------------------------------------- |
| // Implementation fields |
| // ---------------------------------------------------------------------- |
| |
| private final Provider<PlexusBeanLocator> locatorProvider; |
| |
| final TypeLiteral<T> type; |
| |
| private final String[] hints; |
| |
| // ---------------------------------------------------------------------- |
| // Constructors |
| // ---------------------------------------------------------------------- |
| |
| AbstractRequirementProvider( final Provider<PlexusBeanLocator> locatorProvider, final TypeLiteral<T> type, |
| final String[] hints ) |
| { |
| this.locatorProvider = locatorProvider; |
| |
| this.type = type; |
| this.hints = hints; |
| } |
| |
| // ---------------------------------------------------------------------- |
| // Locally-shared methods |
| // ---------------------------------------------------------------------- |
| |
| final Iterable<? extends Entry<String, T>> locate() |
| { |
| return locatorProvider.get().locate( type, hints ); |
| } |
| } |
| |
| /** |
| * {@link Provider} of Plexus requirement maps. |
| */ |
| private static final class RequirementMapProvider<T> |
| extends AbstractRequirementProvider<Map<String, T>, T> |
| { |
| // ---------------------------------------------------------------------- |
| // Constructors |
| // ---------------------------------------------------------------------- |
| |
| RequirementMapProvider( final Provider<PlexusBeanLocator> locatorProvider, final TypeLiteral<T> type, |
| final String[] hints ) |
| { |
| super( locatorProvider, type, hints ); |
| } |
| |
| // ---------------------------------------------------------------------- |
| // Public methods |
| // ---------------------------------------------------------------------- |
| |
| public Map<String, T> get() |
| { |
| return new EntryMapAdapter<String, T>( locate() ); |
| } |
| } |
| |
| /** |
| * {@link Provider} of Plexus requirement lists. |
| */ |
| private static final class RequirementListProvider<T> |
| extends AbstractRequirementProvider<List<T>, T> |
| { |
| // ---------------------------------------------------------------------- |
| // Constructors |
| // ---------------------------------------------------------------------- |
| |
| RequirementListProvider( final Provider<PlexusBeanLocator> locatorProvider, final TypeLiteral<T> type, |
| final String[] hints ) |
| { |
| super( locatorProvider, type, hints ); |
| } |
| |
| // ---------------------------------------------------------------------- |
| // Public methods |
| // ---------------------------------------------------------------------- |
| |
| public List<T> get() |
| { |
| return new EntryListAdapter<String, T>( locate() ); |
| } |
| } |
| |
| /** |
| * {@link Provider} of Plexus requirement sets. |
| */ |
| private static final class RequirementSetProvider<T> |
| extends AbstractRequirementProvider<Set<T>, T> |
| { |
| // ---------------------------------------------------------------------- |
| // Constructors |
| // ---------------------------------------------------------------------- |
| |
| RequirementSetProvider( final Provider<PlexusBeanLocator> locatorProvider, final TypeLiteral<T> type, |
| final String[] hints ) |
| { |
| super( locatorProvider, type, hints ); |
| } |
| |
| // ---------------------------------------------------------------------- |
| // Public methods |
| // ---------------------------------------------------------------------- |
| |
| public Set<T> get() |
| { |
| return new EntrySetAdapter<String, T>( locate() ); |
| } |
| } |
| |
| /** |
| * {@link Provider} of a single Plexus requirement. |
| */ |
| private static final class RequirementProvider<T> |
| extends AbstractRequirementProvider<T, T> |
| { |
| // ---------------------------------------------------------------------- |
| // Constructors |
| // ---------------------------------------------------------------------- |
| |
| RequirementProvider( final Provider<PlexusBeanLocator> locatorProvider, final TypeLiteral<T> type, |
| final String[] hints ) |
| { |
| super( locatorProvider, type, hints ); |
| } |
| |
| // ---------------------------------------------------------------------- |
| // Public methods |
| // ---------------------------------------------------------------------- |
| |
| public T get() |
| { |
| // pick first bean: supports both specific and wildcard lookup |
| final Iterator<? extends Entry<String, T>> i = locate().iterator(); |
| if ( i.hasNext() ) |
| { |
| return i.next().getValue(); |
| } |
| return Roles.throwMissingComponentException( type, null ); |
| } |
| } |
| } |