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.impl;
020
021import java.util.Collection;
022
023import org.eclipse.aether.artifact.Artifact;
024import org.eclipse.aether.metadata.Metadata;
025
026/**
027 * A metadata generator that participates in the installation/deployment of artifacts.
028 *
029 * @provisional This type is provisional and can be changed, moved or removed without prior notice.
030 */
031public interface MetadataGenerator {
032
033    /**
034     * Prepares the generator to transform artifacts.
035     *
036     * @param artifacts The artifacts to install/deploy, must not be {@code null}.
037     * @return The metadata to process (e.g. merge with existing metadata) before artifact transformations, never
038     *         {@code null}.
039     */
040    Collection<? extends Metadata> prepare(Collection<? extends Artifact> artifacts);
041
042    /**
043     * Enables the metadata generator to transform the specified artifact.
044     *
045     * @param artifact The artifact to transform, must not be {@code null}.
046     * @return The transformed artifact (or just the input artifact), never {@code null}.
047     */
048    Artifact transformArtifact(Artifact artifact);
049
050    /**
051     * Allows for metadata generation based on the transformed artifacts.
052     *
053     * @param artifacts The (transformed) artifacts to install/deploy, must not be {@code null}.
054     * @return The additional metadata to process after artifact transformations, never {@code null}.
055     */
056    Collection<? extends Metadata> finish(Collection<? extends Artifact> artifacts);
057}