1 package org.eclipse.aether.graph;
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 java.util.List;
23
24 /**
25 * A cycle within a dependency graph, that is a sequence of dependencies d_1, d_2, ..., d_n where d_1 and d_n have the
26 * same versionless coordinates. In more practical terms, a cycle occurs when a project directly or indirectly depends
27 * on its own output artifact.
28 *
29 * @noimplement This interface is not intended to be implemented by clients.
30 * @noextend This interface is not intended to be extended by clients.
31 */
32 public interface DependencyCycle
33 {
34
35 /**
36 * Gets the dependencies that lead to the first dependency on the cycle, starting from the root of the dependency
37 * graph.
38 *
39 * @return The (read-only) sequence of dependencies that precedes the cycle in the graph, potentially empty but
40 * never {@code null}.
41 */
42 List<Dependency> getPrecedingDependencies();
43
44 /**
45 * Gets the dependencies that actually form the cycle. For example, a -> b -> c -> a, i.e. the last
46 * dependency in this sequence duplicates the first element and closes the cycle. Hence the length of the cycle is
47 * the size of the returned sequence minus 1.
48 *
49 * @return The (read-only) sequence of dependencies that forms the cycle, never {@code null}.
50 */
51 List<Dependency> getCyclicDependencies();
52
53 }