1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.maven.repository.legacy.resolver.conflict;
20
21 import org.apache.maven.artifact.resolver.ResolutionNode;
22 import org.apache.maven.artifact.versioning.ArtifactVersion;
23 import org.apache.maven.artifact.versioning.OverConstrainedVersionException;
24 import org.codehaus.plexus.component.annotations.Component;
25
26 /**
27 * Resolves conflicting artifacts by always selecting the <em>oldest</em> declaration. Oldest is defined as the
28 * declaration whose version is less according to <code>ArtifactVersion.compareTo</code>.
29 *
30 * @author <a href="mailto:markhobson@gmail.com">Mark Hobson</a>
31 * @see ArtifactVersion#compareTo
32 * @since 3.0
33 */
34 @Component(role = ConflictResolver.class, hint = "oldest")
35 public class OldestConflictResolver implements ConflictResolver {
36 // ConflictResolver methods -----------------------------------------------
37
38 /*
39 * @see org.apache.maven.artifact.resolver.conflict.ConflictResolver#resolveConflict(org.apache.maven.artifact.resolver.ResolutionNode,
40 * org.apache.maven.artifact.resolver.ResolutionNode)
41 */
42
43 public ResolutionNode resolveConflict(ResolutionNode node1, ResolutionNode node2) {
44 try {
45 ArtifactVersion version1 = node1.getArtifact().getSelectedVersion();
46 ArtifactVersion version2 = node2.getArtifact().getSelectedVersion();
47
48 return version1.compareTo(version2) <= 0 ? node1 : node2;
49 } catch (OverConstrainedVersionException exception) {
50 // TODO log message or throw exception?
51
52 return null;
53 }
54 }
55 }