1 package org.codehaus.plexus.digest;
2
3 /*
4 * Copyright 2001-2006 The Codehaus.
5 *
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * 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, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 import java.io.File;
20
21 /**
22 * Create a digest for a file.
23 *
24 * @author <a href="mailto:brett@apache.org">Brett Porter</a>
25 */
26 public interface Digester
27 {
28 String ROLE = Digester.class.getName();
29
30 /**
31 * Get the algorithm used for the checksum.
32 *
33 * @return the algorithm
34 */
35 String getAlgorithm();
36
37 /**
38 * The filename extension for this digester.
39 *
40 * @return the filename extension.
41 */
42 String getFilenameExtension();
43
44 /**
45 * Calculate a checksum for a file.
46 *
47 * @param file the file to calculate the checksum for
48 * @return the current checksum.
49 * @throws DigesterException if there was a problem computing the hashcode.
50 */
51 String calc( File file )
52 throws DigesterException;
53
54 /**
55 * Verify that a checksum is correct.
56 *
57 * @param file the file to compute the checksum for
58 * @param checksum the checksum to compare to
59 * @throws DigesterException if there was a problem computing the hashcode.
60 */
61 void verify( File file, String checksum )
62 throws DigesterException;
63 }