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.transformer;
20
21 import org.eclipse.aether.RepositoryException;
22 import org.eclipse.aether.collection.DependencyGraphTransformationContext;
23 import org.eclipse.aether.collection.DependencyGraphTransformer;
24 import org.eclipse.aether.graph.DependencyNode;
25
26 import static java.util.Objects.requireNonNull;
27
28 /**
29 * A dependency graph transformer that does not perform any changes on its input.
30 */
31 public final class NoopDependencyGraphTransformer implements DependencyGraphTransformer {
32
33 /**
34 * A ready-made instance of this dependency graph transformer which can safely be reused throughout an entire
35 * application regardless of multi-threading.
36 */
37 public static final DependencyGraphTransformer INSTANCE = new NoopDependencyGraphTransformer();
38
39 /**
40 * Creates a new instance of this graph transformer. Usually, {@link #INSTANCE} should be used instead.
41 */
42 public NoopDependencyGraphTransformer() {}
43
44 @Override
45 public DependencyNode transformGraph(DependencyNode node, DependencyGraphTransformationContext context)
46 throws RepositoryException {
47 requireNonNull(node, "node cannot be null");
48 requireNonNull(context, "context cannot be null");
49 return node;
50 }
51 }