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.RepositorySystemSession;
024import org.eclipse.aether.repository.RemoteRepository;
025import org.eclipse.aether.spi.connector.transport.Transporter;
026import org.eclipse.aether.spi.connector.transport.TransporterFactory;
027import org.eclipse.aether.transfer.NoTransporterException;
028
029import static java.util.Objects.requireNonNull;
030
031/**
032 * A transporter factory for repositories using the {@code classpath:} protocol. As example, getting an item named
033 * {@code some/file.txt} from a repository with the URL {@code classpath:/base/dir} results in retrieving the resource
034 * {@code base/dir/some/file.txt} from the classpath. The classpath to load the resources from is given via a
035 * {@link ClassLoader} that can be configured via the configuration property {@link #CONFIG_PROP_CLASS_LOADER}.
036 * <p>
037 * <em>Note:</em> Such repositories are read-only and uploads to them are generally not supported.
038 */
039@Named("classpath")
040public final class ClasspathTransporterFactory implements TransporterFactory {
041
042    /**
043     * The key in the repository session's {@link RepositorySystemSession#getConfigProperties() configuration
044     * properties} used to store a {@link ClassLoader} from which resources should be retrieved. If unspecified, the
045     * {@link Thread#getContextClassLoader() context class loader} of the current thread will be used.
046     */
047    public static final String CONFIG_PROP_CLASS_LOADER = "aether.connector.classpath.loader";
048
049    private float priority;
050
051    /**
052     * Creates an (uninitialized) instance of this transporter factory. <em>Note:</em> In case of manual instantiation
053     * by clients, the new factory needs to be configured via its various mutators before first use or runtime errors
054     * will occur.
055     */
056    public ClasspathTransporterFactory() {
057        // enables default constructor
058    }
059
060    public float getPriority() {
061        return priority;
062    }
063
064    /**
065     * Sets the priority of this component.
066     *
067     * @param priority The priority.
068     * @return This component for chaining, never {@code null}.
069     */
070    public ClasspathTransporterFactory setPriority(float priority) {
071        this.priority = priority;
072        return this;
073    }
074
075    public Transporter newInstance(RepositorySystemSession session, RemoteRepository repository)
076            throws NoTransporterException {
077        requireNonNull(session, "session cannot be null");
078        requireNonNull(repository, "repository cannot be null");
079
080        return new ClasspathTransporter(session, repository);
081    }
082}