001 package org.apache.archiva.checksum; 002 003 /* 004 * Licensed to the Apache Software Foundation (ASF) under one 005 * or more contributor license agreements. See the NOTICE file 006 * distributed with this work for additional information 007 * regarding copyright ownership. The ASF licenses this file 008 * to you under the Apache License, Version 2.0 (the 009 * "License"); you may not use this file except in compliance 010 * with the License. You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, 015 * software distributed under the License is distributed on an 016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 017 * KIND, either express or implied. See the License for the 018 * specific language governing permissions and limitations 019 * under the License. 020 */ 021 022 import java.io.IOException; 023 import java.io.InputStream; 024 import java.security.DigestInputStream; 025 import java.security.MessageDigest; 026 import java.security.NoSuchAlgorithmException; 027 import java.util.List; 028 029 import org.apache.commons.io.IOUtils; 030 import org.apache.commons.io.output.NullOutputStream; 031 032 /** 033 * Checksum - simple checksum hashing routines. 034 * 035 * 036 */ 037 public class Checksum 038 { 039 private static final int BUFFER_SIZE = 32768; 040 041 public static void update( List<Checksum> checksums, InputStream stream ) 042 throws IOException 043 { 044 byte[] buffer = new byte[BUFFER_SIZE]; 045 int size = stream.read( buffer, 0, BUFFER_SIZE ); 046 while ( size >= 0 ) 047 { 048 for ( Checksum checksum : checksums ) 049 { 050 checksum.update( buffer, 0, size ); 051 } 052 size = stream.read( buffer, 0, BUFFER_SIZE ); 053 } 054 } 055 056 protected final MessageDigest md; 057 058 private ChecksumAlgorithm checksumAlgorithm; 059 060 public Checksum( ChecksumAlgorithm checksumAlgorithm ) 061 { 062 this.checksumAlgorithm = checksumAlgorithm; 063 try 064 { 065 md = MessageDigest.getInstance( checksumAlgorithm.getAlgorithm() ); 066 } 067 catch ( NoSuchAlgorithmException e ) 068 { 069 // Not really possible, but here none-the-less 070 throw new IllegalStateException( "Unable to initialize MessageDigest algorithm " + checksumAlgorithm.getAlgorithm() 071 + " : " + e.getMessage(), e ); 072 } 073 } 074 075 public String getChecksum() 076 { 077 return Hex.encode( md.digest() ); 078 } 079 080 public ChecksumAlgorithm getAlgorithm() 081 { 082 return this.checksumAlgorithm; 083 } 084 085 public void reset() 086 { 087 md.reset(); 088 } 089 090 public Checksum update( byte[] buffer, int offset, int size ) 091 { 092 md.update( buffer, 0, size ); 093 return this; 094 } 095 096 public Checksum update( InputStream stream ) 097 throws IOException 098 { 099 DigestInputStream dig = new DigestInputStream( stream, md ); 100 IOUtils.copy( dig, new NullOutputStream() ); 101 102 return this; 103 } 104 }