001package org.eclipse.aether.spi.connector.transport;
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 org.eclipse.aether.RepositorySystemSession;
023import org.eclipse.aether.repository.RemoteRepository;
024import org.eclipse.aether.transfer.NoTransporterException;
025
026/**
027 * A factory to create transporters. A transporter is responsible for uploads/downloads to/from a remote repository
028 * using a particular transport protocol. When the repository system needs a transporter for a given remote repository,
029 * it iterates the registered factories in descending order of their priority and calls
030 * {@link #newInstance(RepositorySystemSession, RemoteRepository)} on them. The first transporter returned by a factory
031 * will then be used for the transfer.
032 */
033public interface TransporterFactory
034{
035
036    /**
037     * Tries to create a transporter for the specified remote repository. Typically, a factory will inspect
038     * {@link RemoteRepository#getProtocol()} to determine whether it can handle a repository.
039     * 
040     * @param session The repository system session from which to configure the transporter, must not be {@code null}.
041     *            In particular, a transporter should obey the timeouts configured for the session.
042     * @param repository The remote repository to create a transporter for, must not be {@code null}.
043     * @return The transporter for the given repository, never {@code null}.
044     * @throws NoTransporterException If the factory cannot create a transporter for the specified remote repository.
045     */
046    Transporter newInstance( RepositorySystemSession session, RemoteRepository repository )
047        throws NoTransporterException;
048
049    /**
050     * The priority of this factory. When multiple factories can handle a given repository, factories with higher
051     * priority are preferred over those with lower priority.
052     * 
053     * @return The priority of this factory.
054     */
055    float getPriority();
056
057}