1 package org.eclipse.aether.spi.connector.checksum;
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 java.util.List;
23 import java.util.Map;
24
25 import org.eclipse.aether.RepositorySystemSession;
26 import org.eclipse.aether.spi.connector.ArtifactDownload;
27
28 /**
29 * Component able to provide (expected) checksums to connector beforehand the download happens. Checksum provided by
30 * this component are of kind {@link org.eclipse.aether.spi.connector.checksum.ChecksumPolicy.ChecksumKind#PROVIDED}.
31 *
32 * @since 1.8.0
33 */
34 public interface ProvidedChecksumsSource
35 {
36 /**
37 * May return the provided checksums (for given artifact transfer) from source other than remote repository, or
38 * {@code null} if it have no checksums available for given transfer. Provided checksums are "opt-in" for
39 * transfer, in a way IF they are available upfront, they will be enforced according to checksum policy
40 * in effect. Otherwise, provided checksum verification is completely left out.
41 * <p>
42 * For enabled provided checksum source is completely acceptable to return {@code null} values, as that carries
43 * the meaning "nothing to add here", as there are no checksums to be provided upfront transfer. Semantically, this
44 * is equivalent to returning empty map, but signals the intent better.
45 *
46 * @param transfer The transfer that is about to be executed.
47 * @param checksumAlgorithmFactories The checksum algorithms that are expected.
48 * @return Map of expected checksums, or {@code null}.
49 */
50 Map<String, String> getProvidedArtifactChecksums( RepositorySystemSession session,
51 ArtifactDownload transfer,
52 List<ChecksumAlgorithmFactory> checksumAlgorithmFactories );
53 }