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.io.BufferedInputStream;
23 import java.io.ByteArrayInputStream;
24 import java.io.File;
25 import java.io.FileInputStream;
26 import java.io.IOException;
27 import java.io.InputStream;
28 import java.nio.ByteBuffer;
29 import java.util.LinkedHashMap;
30 import java.util.List;
31 import java.util.Map;
32
33 /**
34 * Helper for checksum operations.
35 *
36 * @since 1.8.0
37 */
38 public final class ChecksumAlgorithmHelper
39 {
40 private ChecksumAlgorithmHelper()
41 {
42 // nop
43 }
44
45 /**
46 * Calculates checksums for specified data.
47 *
48 * @param data The content for which to calculate checksums, must not be {@code null}.
49 * @param factories The checksum algorithm factories to use, must not be {@code null}.
50 * @return The calculated checksums, indexed by algorithm name, or the exception that occurred while trying to
51 * calculate it, never {@code null}.
52 * @throws IOException In case of any problem.
53 */
54 public static Map<String, String> calculate( byte[] data, List<ChecksumAlgorithmFactory> factories )
55 throws IOException
56 {
57 try ( InputStream inputStream = new ByteArrayInputStream( data ) )
58 {
59 return calculate( inputStream, factories );
60 }
61 }
62
63 /**
64 * Calculates checksums for specified file.
65 *
66 * @param file The file for which to calculate checksums, must not be {@code null}.
67 * @param factories The checksum algorithm factories to use, must not be {@code null}.
68 * @return The calculated checksums, indexed by algorithm name, or the exception that occurred while trying to
69 * calculate it, never {@code null}.
70 * @throws IOException In case of any problem.
71 */
72 public static Map<String, String> calculate( File file, List<ChecksumAlgorithmFactory> factories )
73 throws IOException
74 {
75 try ( InputStream inputStream = new BufferedInputStream( new FileInputStream( file ) ) )
76 {
77 return calculate( inputStream, factories );
78 }
79 }
80
81 private static Map<String, String> calculate( InputStream inputStream, List<ChecksumAlgorithmFactory> factories )
82 throws IOException
83 {
84 LinkedHashMap<String, ChecksumAlgorithm> algorithms = new LinkedHashMap<>();
85 factories.forEach( f -> algorithms.put( f.getName(), f.getAlgorithm() ) );
86 final byte[] buffer = new byte[ 1024 * 32 ];
87 for ( ; ; )
88 {
89 int read = inputStream.read( buffer );
90 if ( read < 0 )
91 {
92 break;
93 }
94 for ( ChecksumAlgorithm checksumAlgorithm : algorithms.values() )
95 {
96 checksumAlgorithm.update( ByteBuffer.wrap( buffer, 0, read ) );
97 }
98 }
99 LinkedHashMap<String, String> result = new LinkedHashMap<>();
100 algorithms.forEach( ( k, v ) -> result.put( k, v.checksum() ) );
101 return result;
102 }
103 }