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.manager;
20
21 import java.util.ArrayList;
22 import java.util.Collection;
23
24 import org.eclipse.aether.collection.DependencyManager;
25 import org.eclipse.aether.graph.Exclusion;
26 import org.eclipse.aether.scope.ScopeManager;
27 import org.eclipse.aether.scope.SystemDependencyScope;
28
29 /**
30 * A dependency manager that provides proper transitive dependency management for modern Maven usage.
31 *
32 * <h2>Overview</h2>
33 * <p>
34 * This manager implements proper "transitive dependency management" that works harmoniously
35 * with Maven's ModelBuilder. It produces more precise results regarding versions by respecting
36 * transitive management rules while allowing higher-level management to override lower-level rules.
37 * </p>
38 *
39 * <h2>Key Characteristics</h2>
40 * <ul>
41 * <li><strong>Transitive Management:</strong> {@code deriveUntil=Integer.MAX_VALUE}, {@code applyFrom=2}</li>
42 * <li><strong>ModelBuilder Friendly:</strong> Works in conjunction with, not against, ModelBuilder</li>
43 * <li><strong>Inheritance Aware:</strong> Special handling for scope and optional properties</li>
44 * <li><strong>Precise Versioning:</strong> Obeys transitive management unless managed at higher levels</li>
45 * </ul>
46 *
47 * <h2>Inheritance Handling</h2>
48 * <p>
49 * This manager provides special care for "scope" and "optional" properties that are subject
50 * to inheritance in the dependency graph during later graph transformation steps. These
51 * properties are only derived from the root to prevent interference with inheritance logic.
52 * </p>
53 *
54 * <h2>When to Use</h2>
55 * <p>
56 * This is the <strong>recommended manager for modern Maven projects</strong> that need proper
57 * transitive dependency management while maintaining compatibility with Maven's ModelBuilder.
58 * </p>
59 *
60 * <h2>Comparison with Other Managers</h2>
61 * <ul>
62 * <li>{@link ClassicDependencyManager}: Maven 2.x compatibility, limited transitive support</li>
63 * <li>{@link DefaultDependencyManager}: Aggressive but interferes with ModelBuilder</li>
64 * <li><strong>This manager:</strong> Modern, transitive, ModelBuilder-compatible (recommended)</li>
65 * </ul>
66 *
67 * @author Christian Schulte
68 * @since 1.4.0
69 * @see ClassicDependencyManager
70 * @see DefaultDependencyManager
71 */
72 public final class TransitiveDependencyManager extends AbstractDependencyManager {
73 /**
74 * Creates a new dependency manager without any management information.
75 *
76 * @deprecated Use {@link #TransitiveDependencyManager(ScopeManager)} instead to provide
77 * application-specific scope management. This constructor uses legacy system
78 * dependency scope handling.
79 */
80 @Deprecated
81 public TransitiveDependencyManager() {
82 this(null);
83 }
84
85 /**
86 * Creates a new transitive dependency manager with ModelBuilder-compatible behavior.
87 * <p>
88 * This constructor initializes the manager with settings optimized for modern Maven usage:
89 * <ul>
90 * <li>deriveUntil = Integer.MAX_VALUE (collect management rules at all levels)</li>
91 * <li>applyFrom = 2 (apply management starting from depth 2, respecting ModelBuilder)</li>
92 * <li>Special inheritance handling for scope and optional properties</li>
93 * </ul>
94 *
95 * @param scopeManager application-specific scope manager for handling system dependencies,
96 * may be null to use legacy system dependency scope handling
97 */
98 public TransitiveDependencyManager(ScopeManager scopeManager) {
99 super(Integer.MAX_VALUE, 2, scopeManager);
100 }
101
102 @SuppressWarnings("checkstyle:ParameterNumber")
103 private TransitiveDependencyManager(
104 ArrayList<AbstractDependencyManager> path,
105 int depth,
106 int deriveUntil,
107 int applyFrom,
108 MMap<Key, String> managedVersions,
109 MMap<Key, String> managedScopes,
110 MMap<Key, Boolean> managedOptionals,
111 MMap<Key, String> managedLocalPaths,
112 MMap<Key, Holder<Collection<Exclusion>>> managedExclusions,
113 SystemDependencyScope systemDependencyScope) {
114 super(
115 path,
116 depth,
117 deriveUntil,
118 applyFrom,
119 managedVersions,
120 managedScopes,
121 managedOptionals,
122 managedLocalPaths,
123 managedExclusions,
124 systemDependencyScope);
125 }
126
127 @Override
128 protected DependencyManager newInstance(
129 MMap<Key, String> managedVersions,
130 MMap<Key, String> managedScopes,
131 MMap<Key, Boolean> managedOptionals,
132 MMap<Key, String> managedLocalPaths,
133 MMap<Key, Holder<Collection<Exclusion>>> managedExclusions) {
134 ArrayList<AbstractDependencyManager> path = new ArrayList<>(this.path);
135 path.add(this);
136 return new TransitiveDependencyManager(
137 path,
138 depth + 1,
139 deriveUntil,
140 applyFrom,
141 managedVersions,
142 managedScopes,
143 managedOptionals,
144 managedLocalPaths,
145 managedExclusions,
146 systemDependencyScope);
147 }
148
149 /**
150 * Controls inheritance-based property derivation for scope and optional properties.
151 * <p>
152 * <strong>Why scope and optional are special:</strong> In dependency graphs, these two properties
153 * are subject to inheritance during graph transformation (which is outside ModelBuilder's scope).
154 * Therefore, scope and optional are derived only from the root to prevent interference with
155 * inheritance logic.
156 * </p>
157 * <p>
158 * <strong>The inheritance problem:</strong> If we managed scope/optional from sources below the root,
159 * we would mark nodes as "managed" in the dependency graph. The "managed" flag means "do not touch it,
160 * it is as it should be", which would prevent proper inheritance application during later graph
161 * transformation, causing nodes to end up with incorrect scope or optional states.
162 * </p>
163 * <p>
164 * <strong>Special case:</strong> The "system" scope has special handling due to its unique path requirements.
165 * </p>
166 *
167 * @return true only at depth 0 (root level) to ensure inheritance-based properties are only
168 * derived from the root, false otherwise
169 */
170 @Override
171 protected boolean isInheritedDerived() {
172 return depth == 0;
173 }
174 }