View Javadoc
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.repository;
20  
21  import org.eclipse.aether.repository.Proxy;
22  import org.eclipse.aether.repository.ProxySelector;
23  import org.eclipse.aether.repository.RemoteRepository;
24  
25  import static java.util.Objects.requireNonNull;
26  
27  /**
28   * A proxy selector that delegates to another selector but only if a repository has no proxy yet. If a proxy has already
29   * been assigned to a repository, that is selected.
30   */
31  public final class ConservativeProxySelector implements ProxySelector {
32  
33      private final ProxySelector selector;
34  
35      /**
36       * Creates a new selector that delegates to the specified selector.
37       *
38       * @param selector The selector to delegate to in case a repository has no proxy yet, must not be {@code null}.
39       */
40      public ConservativeProxySelector(ProxySelector selector) {
41          this.selector = requireNonNull(selector, "proxy selector cannot be null");
42      }
43  
44      public Proxy getProxy(RemoteRepository repository) {
45          requireNonNull(repository, "repository cannot be null");
46          Proxy proxy = repository.getProxy();
47          if (proxy != null) {
48              return proxy;
49          }
50          return selector.getProxy(repository);
51      }
52  }