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.util.graph.traverser;
20
21 import org.eclipse.aether.collection.DependencyCollectionContext;
22 import org.eclipse.aether.collection.DependencyTraverser;
23 import org.eclipse.aether.graph.Dependency;
24
25 import static java.util.Objects.requireNonNull;
26
27 /**
28 * A dependency traverser which always or never traverses children.
29 */
30 public final class StaticDependencyTraverser implements DependencyTraverser {
31
32 private final boolean traverse;
33
34 /**
35 * Creates a new traverser with the specified traversal behavior.
36 *
37 * @param traverse {@code true} to traverse all dependencies, {@code false} to never traverse.
38 */
39 public StaticDependencyTraverser(boolean traverse) {
40 this.traverse = traverse;
41 }
42
43 public boolean traverseDependency(Dependency dependency) {
44 requireNonNull(dependency, "dependency cannot be null");
45 return traverse;
46 }
47
48 public DependencyTraverser deriveChildTraverser(DependencyCollectionContext context) {
49 requireNonNull(context, "context cannot be null");
50 return this;
51 }
52
53 @Override
54 public boolean equals(Object obj) {
55 if (this == obj) {
56 return true;
57 } else if (null == obj || !getClass().equals(obj.getClass())) {
58 return false;
59 }
60
61 StaticDependencyTraverser that = (StaticDependencyTraverser) obj;
62 return traverse == that.traverse;
63 }
64
65 @Override
66 public int hashCode() {
67 int hash = getClass().hashCode();
68 hash = hash * 31 + (traverse ? 1 : 0);
69 return hash;
70 }
71 }