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.transport.classpath;
020
021import javax.inject.Named;
022
023import org.eclipse.aether.ConfigurationProperties;
024import org.eclipse.aether.RepositorySystemSession;
025import org.eclipse.aether.repository.RemoteRepository;
026import org.eclipse.aether.spi.connector.transport.Transporter;
027import org.eclipse.aether.spi.connector.transport.TransporterFactory;
028import org.eclipse.aether.transfer.NoTransporterException;
029
030import static java.util.Objects.requireNonNull;
031
032/**
033 * A transporter factory for repositories using the {@code classpath:} protocol. As example, getting an item named
034 * {@code some/file.txt} from a repository with the URL {@code classpath:/base/dir} results in retrieving the resource
035 * {@code base/dir/some/file.txt} from the classpath. The classpath to load the resources from is given via a
036 * {@link ClassLoader} that can be configured via the configuration property {@link #CONFIG_PROP_CLASS_LOADER}.
037 * <p>
038 * <em>Note:</em> Such repositories are read-only and uploads to them are generally not supported.
039 */
040@Named(ClasspathTransporterFactory.NAME)
041public final class ClasspathTransporterFactory implements TransporterFactory {
042    public static final String NAME = "classpath";
043
044    /**
045     * The key in the repository session's {@link RepositorySystemSession#getConfigProperties() configuration
046     * properties} used to store a {@link ClassLoader} from which resources should be retrieved. If unspecified, the
047     * {@link Thread#getContextClassLoader() context class loader} of the current thread will be used.
048     *
049     * @configurationSource {@link RepositorySystemSession#getConfigProperties()}
050     * @configurationType {@link java.lang.ClassLoader}
051     */
052    public static final String CONFIG_PROP_CLASS_LOADER = ConfigurationProperties.PREFIX_TRANSPORT + NAME + ".loader";
053
054    private float priority;
055
056    @Override
057    public float getPriority() {
058        return priority;
059    }
060
061    /**
062     * Sets the priority of this component.
063     *
064     * @param priority The priority.
065     * @return This component for chaining, never {@code null}.
066     */
067    public ClasspathTransporterFactory setPriority(float priority) {
068        this.priority = priority;
069        return this;
070    }
071
072    @Override
073    public Transporter newInstance(RepositorySystemSession session, RemoteRepository repository)
074            throws NoTransporterException {
075        requireNonNull(session, "session cannot be null");
076        requireNonNull(repository, "repository cannot be null");
077
078        return new ClasspathTransporter(session, repository);
079    }
080}