1 package org.apache.maven.shared.jar.identification.hash;
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 org.apache.maven.shared.jar.JarAnalyzer;
23 import org.apache.maven.shared.jar.JarData;
24 import org.codehaus.plexus.digest.DigesterException;
25 import org.codehaus.plexus.digest.StreamingDigester;
26 import org.codehaus.plexus.logging.AbstractLogEnabled;
27 import org.codehaus.plexus.util.IOUtil;
28
29 import java.io.IOException;
30 import java.io.InputStream;
31 import java.util.Iterator;
32 import java.util.jar.JarEntry;
33
34 /**
35 * Analyzer that calculates the hash code for the entire file. Can be used to detect an exact copy of the file's class
36 * data. Useful to see thru a recompile, recompression, or timestamp change.
37 * <p/>
38 * If you are not using Plexus, you must call {@link #setDigester(org.codehaus.plexus.digest.StreamingDigester)} before use
39 *
40 * @plexus.component role="org.apache.maven.shared.jar.identification.hash.JarHashAnalyzer" role-hint="bytecode"
41 */
42 public class JarBytecodeHashAnalyzer
43 extends AbstractLogEnabled
44 implements JarHashAnalyzer
45 {
46 /**
47 * The streaming digester to use for computing the hash. Under Plexus, the default is SHA-1.
48 *
49 * @plexus.requirement role-hint="sha1"
50 */
51 private StreamingDigester digester;
52
53 public String computeHash( JarAnalyzer jarAnalyzer )
54 {
55 JarData jarData = jarAnalyzer.getJarData();
56
57 String result = jarData.getBytecodeHash();
58 if ( result == null )
59 {
60 Iterator it = jarAnalyzer.getClassEntries().iterator();
61
62 try
63 {
64 digester.reset();
65 while ( it.hasNext() )
66 {
67 JarEntry entry = (JarEntry) it.next();
68 computeEntryBytecodeHash( jarAnalyzer.getEntryInputStream( entry ) );
69 }
70 result = digester.calc();
71 jarData.setBytecodeHash( result );
72 }
73 catch ( DigesterException e )
74 {
75 getLogger().warn( "Unable to calculate the hashcode.", e );
76 }
77 catch ( IOException e )
78 {
79 getLogger().warn( "Unable to calculate the hashcode.", e );
80 }
81 }
82 return result;
83 }
84
85 private void computeEntryBytecodeHash( InputStream is )
86 throws IOException, DigesterException
87 {
88 try
89 {
90 digester.update( is );
91 }
92 finally
93 {
94 IOUtil.close( is );
95 }
96 }
97
98 public void setDigester( StreamingDigester digester )
99 {
100 this.digester = digester;
101 }
102 }