001package org.eclipse.aether.transport.classpath;
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 javax.inject.Named;
023
024import java.util.Objects;
025
026import org.eclipse.aether.RepositorySystemSession;
027import org.eclipse.aether.repository.RemoteRepository;
028import org.eclipse.aether.spi.connector.transport.Transporter;
029import org.eclipse.aether.spi.connector.transport.TransporterFactory;
030import org.eclipse.aether.transfer.NoTransporterException;
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( "classpath" )
041public final class ClasspathTransporterFactory
042    implements TransporterFactory
043{
044
045    /**
046     * The key in the repository session's {@link RepositorySystemSession#getConfigProperties() configuration
047     * properties} used to store a {@link ClassLoader} from which resources should be retrieved. If unspecified, the
048     * {@link Thread#getContextClassLoader() context class loader} of the current thread will be used.
049     */
050    public static final String CONFIG_PROP_CLASS_LOADER = "aether.connector.classpath.loader";
051
052    private float priority;
053
054    /**
055     * Creates an (uninitialized) instance of this transporter factory. <em>Note:</em> In case of manual instantiation
056     * by clients, the new factory needs to be configured via its various mutators before first use or runtime errors
057     * will occur.
058     */
059    public ClasspathTransporterFactory()
060    {
061        // enables default constructor
062    }
063
064
065    public float getPriority()
066    {
067        return priority;
068    }
069
070    /**
071     * Sets the priority of this component.
072     *
073     * @param priority The priority.
074     * @return This component for chaining, never {@code null}.
075     */
076    public ClasspathTransporterFactory setPriority( float priority )
077    {
078        this.priority = priority;
079        return this;
080    }
081
082    public Transporter newInstance( RepositorySystemSession session, RemoteRepository repository )
083        throws NoTransporterException
084    {
085        Objects.requireNonNull( "session", "session cannot be null" );
086        Objects.requireNonNull( "repository", "repository cannot be null" );
087
088        return new ClasspathTransporter( session, repository );
089    }
090
091}