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.checksum.DefaultChecksumAlgorithmFactorySelector;
039import org.eclipse.aether.internal.impl.collect.DefaultDependencyCollector;
040import org.eclipse.aether.internal.impl.DefaultDeployer;
041import org.eclipse.aether.internal.impl.DefaultFileProcessor;
042import org.eclipse.aether.internal.impl.DefaultInstaller;
043import org.eclipse.aether.internal.impl.DefaultLocalRepositoryProvider;
044import org.eclipse.aether.internal.impl.DefaultMetadataResolver;
045import org.eclipse.aether.internal.impl.DefaultOfflineController;
046import org.eclipse.aether.internal.impl.DefaultRemoteRepositoryManager;
047import org.eclipse.aether.internal.impl.DefaultRepositoryConnectorProvider;
048import org.eclipse.aether.internal.impl.DefaultRepositoryEventDispatcher;
049import org.eclipse.aether.internal.impl.DefaultRepositoryLayoutProvider;
050import org.eclipse.aether.internal.impl.DefaultRepositorySystem;
051import org.eclipse.aether.internal.impl.DefaultTransporterProvider;
052import org.eclipse.aether.internal.impl.DefaultUpdateCheckManager;
053import org.eclipse.aether.internal.impl.DefaultUpdatePolicyAnalyzer;
054import org.eclipse.aether.internal.impl.EnhancedLocalRepositoryManagerFactory;
055import org.eclipse.aether.internal.impl.Maven2RepositoryLayoutFactory;
056import org.eclipse.aether.internal.impl.SimpleLocalRepositoryManagerFactory;
057import org.eclipse.aether.internal.impl.slf4j.Slf4jLoggerFactory;
058import org.eclipse.aether.internal.impl.synccontext.DefaultSyncContextFactory;
059import org.eclipse.aether.internal.impl.synccontext.named.NamedLockFactorySelector;
060import org.eclipse.aether.internal.impl.synccontext.named.SimpleNamedLockFactorySelector;
061import org.eclipse.aether.spi.connector.checksum.ChecksumAlgorithmFactorySelector;
062import org.eclipse.aether.spi.connector.checksum.ChecksumPolicyProvider;
063import org.eclipse.aether.spi.connector.layout.RepositoryLayoutFactory;
064import org.eclipse.aether.spi.connector.layout.RepositoryLayoutProvider;
065import org.eclipse.aether.spi.connector.transport.TransporterProvider;
066import org.eclipse.aether.spi.io.FileProcessor;
067import org.eclipse.aether.spi.localrepo.LocalRepositoryManagerFactory;
068import org.eclipse.aether.spi.locator.Service;
069import org.eclipse.aether.spi.locator.ServiceLocator;
070import org.eclipse.aether.spi.log.LoggerFactory;
071import org.eclipse.aether.spi.synccontext.SyncContextFactory;
072
073/**
074 * A simple service locator that is already setup with all components from this library. To acquire a complete
075 * repository system, clients need to add an artifact descriptor reader, a version resolver, a version range resolver
076 * and optionally some repository connector and transporter factories to access remote repositories. Once the locator is
077 * fully populated, the repository system can be created like this:
078 * 
079 * <pre>
080 * RepositorySystem repoSystem = serviceLocator.getService( RepositorySystem.class );
081 * </pre>
082 * 
083 * <em>Note:</em> This class is not thread-safe. Clients are expected to create the service locator and the repository
084 * system on a single thread.
085 *
086 * @deprecated Use some out-of-the-box DI implementation instead.
087 */
088@Deprecated
089public final class DefaultServiceLocator
090    implements ServiceLocator
091{
092
093    private class Entry<T>
094    {
095
096        private final Class<T> type;
097
098        private final Collection<Object> providers;
099
100        private List<T> instances;
101
102        Entry( Class<T> type )
103        {
104            this.type = requireNonNull( type, "service type cannot be null" );
105            providers = new LinkedHashSet<>( 8 );
106        }
107
108        public synchronized void setServices( T... services )
109        {
110            providers.clear();
111            if ( services != null )
112            {
113                for ( T service : services )
114                {
115                    providers.add( requireNonNull( service, "service instance cannot be null" ) );
116                }
117            }
118            instances = null;
119        }
120
121        public synchronized void setService( Class<? extends T> impl )
122        {
123            providers.clear();
124            addService( impl );
125        }
126
127        public synchronized void addService( Class<? extends T> impl )
128        {
129            providers.add( requireNonNull( impl, "implementation class cannot be null" ) );
130            instances = null;
131        }
132
133        public T getInstance()
134        {
135            List<T> instances = getInstances();
136            return instances.isEmpty() ? null : instances.get( 0 );
137        }
138
139        public synchronized List<T> getInstances()
140        {
141            if ( instances == null )
142            {
143                instances = new ArrayList<>( providers.size() );
144                for ( Object provider : providers )
145                {
146                    T instance;
147                    if ( provider instanceof Class )
148                    {
149                        instance = newInstance( (Class<?>) provider );
150                    }
151                    else
152                    {
153                        instance = type.cast( provider );
154                    }
155                    if ( instance != null )
156                    {
157                        instances.add( instance );
158                    }
159                }
160                instances = Collections.unmodifiableList( instances );
161            }
162            return instances;
163        }
164
165        private T newInstance( Class<?> impl )
166        {
167            try
168            {
169                Constructor<?> constr = impl.getDeclaredConstructor();
170                if ( !Modifier.isPublic( constr.getModifiers() ) )
171                {
172                    constr.setAccessible( true );
173                }
174                Object obj = constr.newInstance();
175
176                T instance = type.cast( obj );
177                if ( instance instanceof Service )
178                {
179                    ( (Service) instance ).initService( DefaultServiceLocator.this );
180                }
181                return instance;
182            }
183            catch ( Exception | LinkageError e )
184            {
185                serviceCreationFailed( type, impl, e );
186            }
187            return null;
188        }
189
190    }
191
192    private final Map<Class<?>, Entry<?>> entries;
193
194    private ErrorHandler errorHandler;
195
196    /**
197     * Creates a new service locator that already knows about all service implementations included this library.
198     */
199    public DefaultServiceLocator()
200    {
201        entries = new HashMap<>();
202
203        addService( RepositorySystem.class, DefaultRepositorySystem.class );
204        addService( ArtifactResolver.class, DefaultArtifactResolver.class );
205        addService( DependencyCollector.class, DefaultDependencyCollector.class );
206        addService( Deployer.class, DefaultDeployer.class );
207        addService( Installer.class, DefaultInstaller.class );
208        addService( MetadataResolver.class, DefaultMetadataResolver.class );
209        addService( RepositoryLayoutProvider.class, DefaultRepositoryLayoutProvider.class );
210        addService( RepositoryLayoutFactory.class, Maven2RepositoryLayoutFactory.class );
211        addService( TransporterProvider.class, DefaultTransporterProvider.class );
212        addService( ChecksumPolicyProvider.class, DefaultChecksumPolicyProvider.class );
213        addService( RepositoryConnectorProvider.class, DefaultRepositoryConnectorProvider.class );
214        addService( RemoteRepositoryManager.class, DefaultRemoteRepositoryManager.class );
215        addService( UpdateCheckManager.class, DefaultUpdateCheckManager.class );
216        addService( UpdatePolicyAnalyzer.class, DefaultUpdatePolicyAnalyzer.class );
217        addService( FileProcessor.class, DefaultFileProcessor.class );
218        addService( org.eclipse.aether.impl.SyncContextFactory.class,
219            org.eclipse.aether.internal.impl.synccontext.legacy.DefaultSyncContextFactory.class );
220        addService( SyncContextFactory.class, DefaultSyncContextFactory.class );
221        addService( RepositoryEventDispatcher.class, DefaultRepositoryEventDispatcher.class );
222        addService( OfflineController.class, DefaultOfflineController.class );
223        addService( LocalRepositoryProvider.class, DefaultLocalRepositoryProvider.class );
224        addService( LocalRepositoryManagerFactory.class, SimpleLocalRepositoryManagerFactory.class );
225        addService( LocalRepositoryManagerFactory.class, EnhancedLocalRepositoryManagerFactory.class );
226        addService( LoggerFactory.class, Slf4jLoggerFactory.class );
227        addService( TrackingFileManager.class, DefaultTrackingFileManager.class );
228        addService( NamedLockFactorySelector.class, SimpleNamedLockFactorySelector.class );
229        addService( ChecksumAlgorithmFactorySelector.class, DefaultChecksumAlgorithmFactorySelector.class );
230    }
231
232    private <T> Entry<T> getEntry( Class<T> type, boolean create )
233    {
234        @SuppressWarnings( "unchecked" )
235        Entry<T> entry = (Entry<T>) entries.get( requireNonNull( type, "service type cannot be null" ) );
236        if ( entry == null && create )
237        {
238            entry = new Entry<>( type );
239            entries.put( type, entry );
240        }
241        return entry;
242    }
243
244    /**
245     * Sets the implementation class for a service. The specified class must have a no-arg constructor (of any
246     * visibility). If the service implementation itself requires other services for its operation, it should implement
247     * {@link Service} to gain access to this service locator.
248     * 
249     * @param <T> The service type.
250     * @param type The interface describing the service, must not be {@code null}.
251     * @param impl The implementation class of the service, must not be {@code null}.
252     * @return This locator for chaining, never {@code null}.
253     */
254    public <T> DefaultServiceLocator setService( Class<T> type, Class<? extends T> impl )
255    {
256        getEntry( type, true ).setService( impl );
257        return this;
258    }
259
260    /**
261     * Adds an implementation class for a service. The specified class must have a no-arg constructor (of any
262     * visibility). If the service implementation itself requires other services for its operation, it should implement
263     * {@link Service} to gain access to this service locator.
264     * 
265     * @param <T> The service type.
266     * @param type The interface describing the service, must not be {@code null}.
267     * @param impl The implementation class of the service, must not be {@code null}.
268     * @return This locator for chaining, never {@code null}.
269     */
270    public <T> DefaultServiceLocator addService( Class<T> type, Class<? extends T> impl )
271    {
272        getEntry( type, true ).addService( impl );
273        return this;
274    }
275
276    /**
277     * Sets the instances for a service.
278     * 
279     * @param <T> The service type.
280     * @param type The interface describing the service, must not be {@code null}.
281     * @param services The instances of the service, may be {@code null} but must not contain {@code null} elements.
282     * @return This locator for chaining, never {@code null}.
283     */
284    public <T> DefaultServiceLocator setServices( Class<T> type, T... services )
285    {
286        getEntry( type, true ).setServices( services );
287        return this;
288    }
289
290    public <T> T getService( Class<T> type )
291    {
292        Entry<T> entry = getEntry( type, false );
293        return ( entry != null ) ? entry.getInstance() : null;
294    }
295
296    public <T> List<T> getServices( Class<T> type )
297    {
298        Entry<T> entry = getEntry( type, false );
299        return ( entry != null ) ? entry.getInstances() : null;
300    }
301
302    private void serviceCreationFailed( Class<?> type, Class<?> impl, Throwable exception )
303    {
304        if ( errorHandler != null )
305        {
306            errorHandler.serviceCreationFailed( type, impl, exception );
307        }
308    }
309
310    /**
311     * Sets the error handler to use.
312     * 
313     * @param errorHandler The error handler to use, may be {@code null} to ignore/swallow errors.
314     */
315    public void setErrorHandler( ErrorHandler errorHandler )
316    {
317        this.errorHandler = errorHandler;
318    }
319
320    /**
321     * A hook to customize the handling of errors encountered while locating a service implementation.
322     */
323    public abstract static class ErrorHandler
324    {
325
326        /**
327         * Handles errors during creation of a service. The default implemention does nothing.
328         * 
329         * @param type The interface describing the service, must not be {@code null}.
330         * @param impl The implementation class of the service, must not be {@code null}.
331         * @param exception The error that occurred while trying to instantiate the implementation class, must not be
332         *            {@code null}.
333         */
334        public void serviceCreationFailed( Class<?> type, Class<?> impl, Throwable exception )
335        {
336        }
337
338    }
339
340}