1 package org.eclipse.aether.util.graph.selector;
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.eclipse.aether.collection.DependencyCollectionContext;
23 import org.eclipse.aether.collection.DependencySelector;
24 import org.eclipse.aether.graph.Dependency;
25
26 /**
27 * A dependency selector that excludes optional dependencies which occur beyond level one of the dependency graph.
28 *
29 * @see Dependency#isOptional()
30 */
31 public final class OptionalDependencySelector
32 implements DependencySelector
33 {
34
35 private final int depth;
36
37 /**
38 * Creates a new selector to exclude optional transitive dependencies.
39 */
40 public OptionalDependencySelector()
41 {
42 depth = 0;
43 }
44
45 private OptionalDependencySelector( int depth )
46 {
47 this.depth = depth;
48 }
49
50 public boolean selectDependency( Dependency dependency )
51 {
52 return depth < 2 || !dependency.isOptional();
53 }
54
55 public DependencySelector deriveChildSelector( DependencyCollectionContext context )
56 {
57 if ( depth >= 2 )
58 {
59 return this;
60 }
61
62 return new OptionalDependencySelector( depth + 1 );
63 }
64
65 @Override
66 public boolean equals( Object obj )
67 {
68 if ( this == obj )
69 {
70 return true;
71 }
72 else if ( null == obj || !getClass().equals( obj.getClass() ) )
73 {
74 return false;
75 }
76
77 OptionalDependencySelector that = (OptionalDependencySelector) obj;
78 return depth == that.depth;
79 }
80
81 @Override
82 public int hashCode()
83 {
84 int hash = getClass().hashCode();
85 hash = hash * 31 + depth;
86 return hash;
87 }
88
89 @Override
90 public String toString()
91 {
92 return String.format( "%s(depth: %d)", this.getClass().getSimpleName(), this.depth );
93 }
94
95 }