001package org.eclipse.aether.impl;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 * 
012 *  http://www.apache.org/licenses/LICENSE-2.0
013 * 
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import java.lang.reflect.Constructor;
023import java.lang.reflect.Modifier;
024import java.util.ArrayList;
025import java.util.Collection;
026import java.util.Collections;
027import java.util.HashMap;
028import java.util.LinkedHashSet;
029import java.util.List;
030import java.util.Map;
031import static java.util.Objects.requireNonNull;
032
033import org.eclipse.aether.RepositorySystem;
034import org.eclipse.aether.internal.impl.DefaultArtifactResolver;
035import org.eclipse.aether.internal.impl.DefaultChecksumPolicyProvider;
036import org.eclipse.aether.internal.impl.DefaultTrackingFileManager;
037import org.eclipse.aether.internal.impl.TrackingFileManager;
038import org.eclipse.aether.internal.impl.collect.DefaultDependencyCollector;
039import org.eclipse.aether.internal.impl.DefaultDeployer;
040import org.eclipse.aether.internal.impl.DefaultFileProcessor;
041import org.eclipse.aether.internal.impl.DefaultInstaller;
042import org.eclipse.aether.internal.impl.DefaultLocalRepositoryProvider;
043import org.eclipse.aether.internal.impl.DefaultMetadataResolver;
044import org.eclipse.aether.internal.impl.DefaultOfflineController;
045import org.eclipse.aether.internal.impl.DefaultRemoteRepositoryManager;
046import org.eclipse.aether.internal.impl.DefaultRepositoryConnectorProvider;
047import org.eclipse.aether.internal.impl.DefaultRepositoryEventDispatcher;
048import org.eclipse.aether.internal.impl.DefaultRepositoryLayoutProvider;
049import org.eclipse.aether.internal.impl.DefaultRepositorySystem;
050import org.eclipse.aether.internal.impl.DefaultTransporterProvider;
051import org.eclipse.aether.internal.impl.DefaultUpdateCheckManager;
052import org.eclipse.aether.internal.impl.DefaultUpdatePolicyAnalyzer;
053import org.eclipse.aether.internal.impl.EnhancedLocalRepositoryManagerFactory;
054import org.eclipse.aether.internal.impl.Maven2RepositoryLayoutFactory;
055import org.eclipse.aether.internal.impl.SimpleLocalRepositoryManagerFactory;
056import org.eclipse.aether.internal.impl.slf4j.Slf4jLoggerFactory;
057import org.eclipse.aether.internal.impl.synccontext.DefaultSyncContextFactory;
058import org.eclipse.aether.internal.impl.synccontext.named.NamedLockFactorySelector;
059import org.eclipse.aether.internal.impl.synccontext.named.SimpleNamedLockFactorySelector;
060import org.eclipse.aether.spi.connector.checksum.ChecksumPolicyProvider;
061import org.eclipse.aether.spi.connector.layout.RepositoryLayoutFactory;
062import org.eclipse.aether.spi.connector.layout.RepositoryLayoutProvider;
063import org.eclipse.aether.spi.connector.transport.TransporterProvider;
064import org.eclipse.aether.spi.io.FileProcessor;
065import org.eclipse.aether.spi.localrepo.LocalRepositoryManagerFactory;
066import org.eclipse.aether.spi.locator.Service;
067import org.eclipse.aether.spi.locator.ServiceLocator;
068import org.eclipse.aether.spi.log.LoggerFactory;
069import org.eclipse.aether.spi.synccontext.SyncContextFactory;
070
071/**
072 * A simple service locator that is already setup with all components from this library. To acquire a complete
073 * repository system, clients need to add an artifact descriptor reader, a version resolver, a version range resolver
074 * and optionally some repository connector and transporter factories to access remote repositories. Once the locator is
075 * fully populated, the repository system can be created like this:
076 * 
077 * <pre>
078 * RepositorySystem repoSystem = serviceLocator.getService( RepositorySystem.class );
079 * </pre>
080 * 
081 * <em>Note:</em> This class is not thread-safe. Clients are expected to create the service locator and the repository
082 * system on a single thread.
083 *
084 * @deprecated Use some out-of-the-box DI implementation instead.
085 */
086@Deprecated
087public final class DefaultServiceLocator
088    implements ServiceLocator
089{
090
091    private class Entry<T>
092    {
093
094        private final Class<T> type;
095
096        private final Collection<Object> providers;
097
098        private List<T> instances;
099
100        Entry( Class<T> type )
101        {
102            this.type = requireNonNull( type, "service type cannot be null" );
103            providers = new LinkedHashSet<>( 8 );
104        }
105
106        public synchronized void setServices( T... services )
107        {
108            providers.clear();
109            if ( services != null )
110            {
111                for ( T service : services )
112                {
113                    providers.add( requireNonNull( service, "service instance cannot be null" ) );
114                }
115            }
116            instances = null;
117        }
118
119        public synchronized void setService( Class<? extends T> impl )
120        {
121            providers.clear();
122            addService( impl );
123        }
124
125        public synchronized void addService( Class<? extends T> impl )
126        {
127            providers.add( requireNonNull( impl, "implementation class cannot be null" ) );
128            instances = null;
129        }
130
131        public T getInstance()
132        {
133            List<T> instances = getInstances();
134            return instances.isEmpty() ? null : instances.get( 0 );
135        }
136
137        public synchronized List<T> getInstances()
138        {
139            if ( instances == null )
140            {
141                instances = new ArrayList<>( providers.size() );
142                for ( Object provider : providers )
143                {
144                    T instance;
145                    if ( provider instanceof Class )
146                    {
147                        instance = newInstance( (Class<?>) provider );
148                    }
149                    else
150                    {
151                        instance = type.cast( provider );
152                    }
153                    if ( instance != null )
154                    {
155                        instances.add( instance );
156                    }
157                }
158                instances = Collections.unmodifiableList( instances );
159            }
160            return instances;
161        }
162
163        private T newInstance( Class<?> impl )
164        {
165            try
166            {
167                Constructor<?> constr = impl.getDeclaredConstructor();
168                if ( !Modifier.isPublic( constr.getModifiers() ) )
169                {
170                    constr.setAccessible( true );
171                }
172                Object obj = constr.newInstance();
173
174                T instance = type.cast( obj );
175                if ( instance instanceof Service )
176                {
177                    ( (Service) instance ).initService( DefaultServiceLocator.this );
178                }
179                return instance;
180            }
181            catch ( Exception | LinkageError e )
182            {
183                serviceCreationFailed( type, impl, e );
184            }
185            return null;
186        }
187
188    }
189
190    private final Map<Class<?>, Entry<?>> entries;
191
192    private ErrorHandler errorHandler;
193
194    /**
195     * Creates a new service locator that already knows about all service implementations included this library.
196     */
197    public DefaultServiceLocator()
198    {
199        entries = new HashMap<>();
200
201        addService( RepositorySystem.class, DefaultRepositorySystem.class );
202        addService( ArtifactResolver.class, DefaultArtifactResolver.class );
203        addService( DependencyCollector.class, DefaultDependencyCollector.class );
204        addService( Deployer.class, DefaultDeployer.class );
205        addService( Installer.class, DefaultInstaller.class );
206        addService( MetadataResolver.class, DefaultMetadataResolver.class );
207        addService( RepositoryLayoutProvider.class, DefaultRepositoryLayoutProvider.class );
208        addService( RepositoryLayoutFactory.class, Maven2RepositoryLayoutFactory.class );
209        addService( TransporterProvider.class, DefaultTransporterProvider.class );
210        addService( ChecksumPolicyProvider.class, DefaultChecksumPolicyProvider.class );
211        addService( RepositoryConnectorProvider.class, DefaultRepositoryConnectorProvider.class );
212        addService( RemoteRepositoryManager.class, DefaultRemoteRepositoryManager.class );
213        addService( UpdateCheckManager.class, DefaultUpdateCheckManager.class );
214        addService( UpdatePolicyAnalyzer.class, DefaultUpdatePolicyAnalyzer.class );
215        addService( FileProcessor.class, DefaultFileProcessor.class );
216        addService( org.eclipse.aether.impl.SyncContextFactory.class,
217            org.eclipse.aether.internal.impl.synccontext.legacy.DefaultSyncContextFactory.class );
218        addService( SyncContextFactory.class, DefaultSyncContextFactory.class );
219        addService( RepositoryEventDispatcher.class, DefaultRepositoryEventDispatcher.class );
220        addService( OfflineController.class, DefaultOfflineController.class );
221        addService( LocalRepositoryProvider.class, DefaultLocalRepositoryProvider.class );
222        addService( LocalRepositoryManagerFactory.class, SimpleLocalRepositoryManagerFactory.class );
223        addService( LocalRepositoryManagerFactory.class, EnhancedLocalRepositoryManagerFactory.class );
224        addService( LoggerFactory.class, Slf4jLoggerFactory.class );
225        addService( TrackingFileManager.class, DefaultTrackingFileManager.class );
226        addService( NamedLockFactorySelector.class, SimpleNamedLockFactorySelector.class );
227    }
228
229    private <T> Entry<T> getEntry( Class<T> type, boolean create )
230    {
231        @SuppressWarnings( "unchecked" )
232        Entry<T> entry = (Entry<T>) entries.get( requireNonNull( type, "service type cannot be null" ) );
233        if ( entry == null && create )
234        {
235            entry = new Entry<>( type );
236            entries.put( type, entry );
237        }
238        return entry;
239    }
240
241    /**
242     * Sets the implementation class for a service. The specified class must have a no-arg constructor (of any
243     * visibility). If the service implementation itself requires other services for its operation, it should implement
244     * {@link Service} to gain access to this service locator.
245     * 
246     * @param <T> The service type.
247     * @param type The interface describing the service, must not be {@code null}.
248     * @param impl The implementation class of the service, must not be {@code null}.
249     * @return This locator for chaining, never {@code null}.
250     */
251    public <T> DefaultServiceLocator setService( Class<T> type, Class<? extends T> impl )
252    {
253        getEntry( type, true ).setService( impl );
254        return this;
255    }
256
257    /**
258     * Adds an implementation class for a service. The specified class must have a no-arg constructor (of any
259     * visibility). If the service implementation itself requires other services for its operation, it should implement
260     * {@link Service} to gain access to this service locator.
261     * 
262     * @param <T> The service type.
263     * @param type The interface describing the service, must not be {@code null}.
264     * @param impl The implementation class of the service, must not be {@code null}.
265     * @return This locator for chaining, never {@code null}.
266     */
267    public <T> DefaultServiceLocator addService( Class<T> type, Class<? extends T> impl )
268    {
269        getEntry( type, true ).addService( impl );
270        return this;
271    }
272
273    /**
274     * Sets the instances for a service.
275     * 
276     * @param <T> The service type.
277     * @param type The interface describing the service, must not be {@code null}.
278     * @param services The instances of the service, may be {@code null} but must not contain {@code null} elements.
279     * @return This locator for chaining, never {@code null}.
280     */
281    public <T> DefaultServiceLocator setServices( Class<T> type, T... services )
282    {
283        getEntry( type, true ).setServices( services );
284        return this;
285    }
286
287    public <T> T getService( Class<T> type )
288    {
289        Entry<T> entry = getEntry( type, false );
290        return ( entry != null ) ? entry.getInstance() : null;
291    }
292
293    public <T> List<T> getServices( Class<T> type )
294    {
295        Entry<T> entry = getEntry( type, false );
296        return ( entry != null ) ? entry.getInstances() : null;
297    }
298
299    private void serviceCreationFailed( Class<?> type, Class<?> impl, Throwable exception )
300    {
301        if ( errorHandler != null )
302        {
303            errorHandler.serviceCreationFailed( type, impl, exception );
304        }
305    }
306
307    /**
308     * Sets the error handler to use.
309     * 
310     * @param errorHandler The error handler to use, may be {@code null} to ignore/swallow errors.
311     */
312    public void setErrorHandler( ErrorHandler errorHandler )
313    {
314        this.errorHandler = errorHandler;
315    }
316
317    /**
318     * A hook to customize the handling of errors encountered while locating a service implementation.
319     */
320    public abstract static class ErrorHandler
321    {
322
323        /**
324         * Handles errors during creation of a service. The default implemention does nothing.
325         * 
326         * @param type The interface describing the service, must not be {@code null}.
327         * @param impl The implementation class of the service, must not be {@code null}.
328         * @param exception The error that occurred while trying to instantiate the implementation class, must not be
329         *            {@code null}.
330         */
331        public void serviceCreationFailed( Class<?> type, Class<?> impl, Throwable exception )
332        {
333        }
334
335    }
336
337}