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