001package org.eclipse.aether.metadata;
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 java.io.File;
023
024import org.eclipse.aether.RepositoryException;
025
026/**
027 * A piece of metadata that needs to be merged with any current metadata before installation/deployment.
028 */
029public interface MergeableMetadata
030    extends Metadata
031{
032
033    /**
034     * Merges this metadata into the current metadata (if any). Note that this method will be invoked regardless whether
035     * metadata currently exists or not.
036     * 
037     * @param current The path to the current metadata file, may not exist but must not be {@code null}.
038     * @param result The path to the result file where the merged metadata should be stored, must not be {@code null}.
039     * @throws RepositoryException If the metadata could not be merged.
040     */
041    void merge( File current, File result )
042        throws RepositoryException;
043
044    /**
045     * Indicates whether this metadata has been merged.
046     * 
047     * @return {@code true} if the metadata has been merged, {@code false} otherwise.
048     */
049    boolean isMerged();
050
051}