cstamas commented on a change in pull request #77: URL: https://github.com/apache/maven-resolver/pull/77#discussion_r605555586
########## File path: maven-resolver-impl/src/main/java/org/eclipse/aether/internal/impl/synccontext/DefaultSyncContextFactory.java ########## @@ -0,0 +1,86 @@ +package org.eclipse.aether.internal.impl.synccontext; + +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +import org.eclipse.aether.RepositorySystemSession; +import org.eclipse.aether.SyncContext; +import org.eclipse.aether.spi.synccontext.SyncContextFactory; + +import javax.inject.Inject; +import javax.inject.Named; +import javax.inject.Singleton; +import java.util.HashMap; +import java.util.Map; +import java.util.Objects; + +/** + * Default {@link SyncContextFactory} implementation that delegates to some {@link SyncContextFactoryDelegate} + * implementation. + */ +@Singleton +@Named +public final class DefaultSyncContextFactory + implements SyncContextFactory, org.eclipse.aether.impl.SyncContextFactory +{ + private static final String SYNC_CONTEXT_FACTORY_NAME = System.getProperty( + "aether.syncContext.impl", NamedSyncContextFactory.NAME + ); + + private final SyncContextFactoryDelegate delegate; + + /** + * Constructor used with DI, where factories are injected and selected based on key. + */ + @Inject + public DefaultSyncContextFactory( final Map<String, SyncContextFactoryDelegate> delegates ) + { + Objects.requireNonNull( delegates ); + this.delegate = selectDelegate( delegates ); + } + + /** + * Default constructor. + */ + public DefaultSyncContextFactory() + { + HashMap<String, SyncContextFactoryDelegate> delegates = new HashMap<>( 3 ); + delegates.put( NoLockSyncContextFactory.NAME, new NoLockSyncContextFactory() ); + delegates.put( GlobalSyncContextFactory.NAME, new GlobalSyncContextFactory() ); + delegates.put( NamedSyncContextFactory.NAME, new NamedSyncContextFactory() ); + this.delegate = selectDelegate( delegates ); + } + + private SyncContextFactoryDelegate selectDelegate( final Map<String, SyncContextFactoryDelegate> delegates ) + { + SyncContextFactoryDelegate delegate = delegates.get( SYNC_CONTEXT_FACTORY_NAME ); + if ( delegate == null ) + { + throw new IllegalArgumentException( "Unknown SyncContextFactory impl: " + SYNC_CONTEXT_FACTORY_NAME Review comment: um, matter of taste IMHO: the factory name is really a "parameter" (as user may override default value), now, that given name is available or unavailable, may depend on many other factors, like badly set up (missing) dependency for example, that is again, user issue.... am really neutral on this question: state vs argument here. Just as a side-note: all this would be more clearly visible, once ServiceLocator is gone, so ctor injection would be explicit, but again, we are not yet there. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
