View Javadoc
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.eclipse.aether.graph;
20  
21  import java.util.List;
22  
23  /**
24   * 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
25   * same versionless coordinates. In more practical terms, a cycle occurs when a project directly or indirectly depends
26   * on its own output artifact.
27   *
28   * @noimplement This interface is not intended to be implemented by clients.
29   * @noextend This interface is not intended to be extended by clients.
30   */
31  public interface DependencyCycle {
32  
33      /**
34       * Gets the dependencies that lead to the first dependency on the cycle, starting from the root of the dependency
35       * graph.
36       *
37       * @return The (read-only) sequence of dependencies that precedes the cycle in the graph, potentially empty but
38       *         never {@code null}.
39       */
40      List<Dependency> getPrecedingDependencies();
41  
42      /**
43       * Gets the dependencies that actually form the cycle. For example, a -&gt; b -&gt; c -&gt; a, i.e. the last
44       * dependency in this sequence duplicates the first element and closes the cycle. Hence the length of the cycle is
45       * the size of the returned sequence minus 1.
46       *
47       * @return The (read-only) sequence of dependencies that forms the cycle, never {@code null}.
48       */
49      List<Dependency> getCyclicDependencies();
50  }