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.spi.connector.checksum;
20
21 import java.io.BufferedInputStream;
22 import java.io.ByteArrayInputStream;
23 import java.io.File;
24 import java.io.IOException;
25 import java.io.InputStream;
26 import java.nio.ByteBuffer;
27 import java.nio.file.Files;
28 import java.util.LinkedHashMap;
29 import java.util.List;
30 import java.util.Map;
31
32 /**
33 * Helper for checksum operations.
34 *
35 * @since 1.8.0
36 */
37 public final class ChecksumAlgorithmHelper {
38 private ChecksumAlgorithmHelper() {
39 // nop
40 }
41
42 /**
43 * Calculates checksums for specified data.
44 *
45 * @param data The content for which to calculate checksums, must not be {@code null}.
46 * @param factories The checksum algorithm factories to use, must not be {@code null}.
47 * @return The calculated checksums, indexed by algorithm name, or the exception that occurred while trying to
48 * calculate it, never {@code null}.
49 * @throws IOException In case of any problem.
50 */
51 public static Map<String, String> calculate(byte[] data, List<ChecksumAlgorithmFactory> factories)
52 throws IOException {
53 try (InputStream inputStream = new ByteArrayInputStream(data)) {
54 return calculate(inputStream, factories);
55 }
56 }
57
58 /**
59 * Calculates checksums for specified file.
60 *
61 * @param file The file for which to calculate checksums, must not be {@code null}.
62 * @param factories The checksum algorithm factories to use, must not be {@code null}.
63 * @return The calculated checksums, indexed by algorithm name, or the exception that occurred while trying to
64 * calculate it, never {@code null}.
65 * @throws IOException In case of any problem.
66 */
67 public static Map<String, String> calculate(File file, List<ChecksumAlgorithmFactory> factories)
68 throws IOException {
69 try (InputStream inputStream = new BufferedInputStream(Files.newInputStream(file.toPath()))) {
70 return calculate(inputStream, factories);
71 }
72 }
73
74 private static Map<String, String> calculate(InputStream inputStream, List<ChecksumAlgorithmFactory> factories)
75 throws IOException {
76 LinkedHashMap<String, ChecksumAlgorithm> algorithms = new LinkedHashMap<>();
77 factories.forEach(f -> algorithms.put(f.getName(), f.getAlgorithm()));
78 final byte[] buffer = new byte[1024 * 32];
79 for (; ; ) {
80 int read = inputStream.read(buffer);
81 if (read < 0) {
82 break;
83 }
84 for (ChecksumAlgorithm checksumAlgorithm : algorithms.values()) {
85 checksumAlgorithm.update(ByteBuffer.wrap(buffer, 0, read));
86 }
87 }
88 LinkedHashMap<String, String> result = new LinkedHashMap<>();
89 algorithms.forEach((k, v) -> result.put(k, v.checksum()));
90 return result;
91 }
92 }