001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.eclipse.aether.internal.impl;
020
021import javax.inject.Inject;
022import javax.inject.Named;
023import javax.inject.Singleton;
024
025import java.util.ArrayList;
026import java.util.Collection;
027import java.util.List;
028import java.util.Set;
029
030import org.eclipse.aether.RepositorySystemSession;
031import org.eclipse.aether.repository.RemoteRepository;
032import org.eclipse.aether.spi.connector.transport.Transporter;
033import org.eclipse.aether.spi.connector.transport.TransporterFactory;
034import org.eclipse.aether.spi.connector.transport.TransporterProvider;
035import org.eclipse.aether.spi.locator.Service;
036import org.eclipse.aether.spi.locator.ServiceLocator;
037import org.eclipse.aether.transfer.NoTransporterException;
038import org.slf4j.Logger;
039import org.slf4j.LoggerFactory;
040
041import static java.util.Objects.requireNonNull;
042
043/**
044 */
045@Singleton
046@Named
047public final class DefaultTransporterProvider implements TransporterProvider, Service {
048
049    private static final Logger LOGGER = LoggerFactory.getLogger(DefaultTransporterProvider.class);
050
051    private Collection<TransporterFactory> factories = new ArrayList<>();
052
053    @Deprecated
054    public DefaultTransporterProvider() {
055        // enables default constructor
056    }
057
058    @Inject
059    public DefaultTransporterProvider(Set<TransporterFactory> transporterFactories) {
060        setTransporterFactories(transporterFactories);
061    }
062
063    public void initService(ServiceLocator locator) {
064        setTransporterFactories(locator.getServices(TransporterFactory.class));
065    }
066
067    public DefaultTransporterProvider addTransporterFactory(TransporterFactory factory) {
068        factories.add(requireNonNull(factory, "transporter factory cannot be null"));
069        return this;
070    }
071
072    public DefaultTransporterProvider setTransporterFactories(Collection<TransporterFactory> factories) {
073        if (factories == null) {
074            this.factories = new ArrayList<>();
075        } else {
076            this.factories = factories;
077        }
078        return this;
079    }
080
081    public Transporter newTransporter(RepositorySystemSession session, RemoteRepository repository)
082            throws NoTransporterException {
083        requireNonNull(session, "session cannot be null");
084        requireNonNull(repository, "repository cannot be null");
085
086        PrioritizedComponents<TransporterFactory> factories = new PrioritizedComponents<>(session);
087        for (TransporterFactory factory : this.factories) {
088            factories.add(factory, factory.getPriority());
089        }
090
091        List<NoTransporterException> errors = new ArrayList<>();
092        for (PrioritizedComponent<TransporterFactory> factory : factories.getEnabled()) {
093            try {
094                Transporter transporter = factory.getComponent().newInstance(session, repository);
095
096                if (LOGGER.isDebugEnabled()) {
097                    StringBuilder buffer = new StringBuilder(256);
098                    buffer.append("Using transporter ")
099                            .append(transporter.getClass().getSimpleName());
100                    Utils.appendClassLoader(buffer, transporter);
101                    buffer.append(" with priority ").append(factory.getPriority());
102                    buffer.append(" for ").append(repository.getUrl());
103                    LOGGER.debug(buffer.toString());
104                }
105
106                return transporter;
107            } catch (NoTransporterException e) {
108                // continue and try next factory
109                errors.add(e);
110            }
111        }
112        if (LOGGER.isDebugEnabled() && errors.size() > 1) {
113            for (Exception e : errors) {
114                LOGGER.debug("Could not obtain transporter factory for {}", repository, e);
115            }
116        }
117
118        StringBuilder buffer = new StringBuilder(256);
119        if (factories.isEmpty()) {
120            buffer.append("No transporter factories registered");
121        } else {
122            buffer.append("Cannot access ").append(repository.getUrl());
123            buffer.append(" using the registered transporter factories: ");
124            factories.list(buffer);
125        }
126
127        throw new NoTransporterException(repository, buffer.toString(), errors.size() == 1 ? errors.get(0) : null);
128    }
129}