1 package org.apache.maven.repository.legacy.resolver.conflict;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import org.apache.maven.artifact.resolver.ResolutionNode;
23 import org.apache.maven.artifact.versioning.ArtifactVersion;
24 import org.apache.maven.artifact.versioning.OverConstrainedVersionException;
25 import org.codehaus.plexus.component.annotations.Component;
26
27 /**
28 * Resolves conflicting artifacts by always selecting the <em>oldest</em> declaration. Oldest is defined as the
29 * declaration whose version is less according to <code>ArtifactVersion.compareTo</code>.
30 *
31 * @author <a href="mailto:markhobson@gmail.com">Mark Hobson</a>
32 * @see ArtifactVersion#compareTo
33 * @since 3.0
34 */
35 @Component( role = ConflictResolver.class, hint = "oldest" )
36 public class OldestConflictResolver
37 implements ConflictResolver
38 {
39 // ConflictResolver methods -----------------------------------------------
40
41 /*
42 * @see org.apache.maven.artifact.resolver.conflict.ConflictResolver#resolveConflict(org.apache.maven.artifact.resolver.ResolutionNode,
43 * org.apache.maven.artifact.resolver.ResolutionNode)
44 */
45
46 public ResolutionNode resolveConflict( ResolutionNode node1, ResolutionNode node2 )
47 {
48 try
49 {
50 ArtifactVersion version1 = node1.getArtifact().getSelectedVersion();
51 ArtifactVersion version2 = node2.getArtifact().getSelectedVersion();
52
53 return version1.compareTo( version2 ) <= 0 ? node1 : node2;
54 }
55 catch ( OverConstrainedVersionException exception )
56 {
57 // TODO: log message or throw exception?
58
59 return null;
60 }
61 }
62 }