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.artifact;
20
21 import org.eclipse.aether.artifact.ArtifactType;
22 import org.eclipse.aether.artifact.ArtifactTypeRegistry;
23
24 /**
25 * An artifact type registry which first consults its own mappings and in case of an unknown type falls back to another
26 * type registry.
27 */
28 public final class OverlayArtifactTypeRegistry extends SimpleArtifactTypeRegistry {
29
30 private final ArtifactTypeRegistry delegate;
31
32 /**
33 * Creates a new artifact type registry with initially no registered artifact types and the specified fallback
34 * registry. Use {@link #add(ArtifactType)} to populate the registry.
35 *
36 * @param delegate The artifact type registry to fall back to, may be {@code null}.
37 */
38 public OverlayArtifactTypeRegistry(ArtifactTypeRegistry delegate) {
39 this.delegate = delegate;
40 }
41
42 /**
43 * Adds the specified artifact type to the registry.
44 *
45 * @param type The artifact type to add, must not be {@code null}.
46 * @return This registry for chaining, never {@code null}.
47 */
48 public OverlayArtifactTypeRegistry add(ArtifactType type) {
49 super.add(type);
50 return this;
51 }
52
53 public ArtifactType get(String typeId) {
54 ArtifactType type = super.get(typeId);
55
56 if (type == null && delegate != null) {
57 type = delegate.get(typeId);
58 }
59
60 return type;
61 }
62 }