001    /*
002     * Sonar, open source software quality management tool.
003     * Copyright (C) 2008-2012 SonarSource
004     * mailto:contact AT sonarsource DOT com
005     *
006     * Sonar is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 3 of the License, or (at your option) any later version.
010     *
011     * Sonar is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public
017     * License along with Sonar; if not, write to the Free Software
018     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
019     */
020    package org.sonar.plugins.core.timemachine;
021    
022    import com.google.common.collect.Lists;
023    import org.apache.commons.codec.digest.DigestUtils;
024    import org.apache.commons.lang.StringUtils;
025    
026    import java.util.List;
027    
028    public final class SourceChecksum {
029    
030      private static final String SPACE_CHARS = "\t\n\r ";
031    
032      private SourceChecksum() {
033        // only static methods
034      }
035    
036      /**
037       * @param line line number (first line has number 1)
038       * @return checksum or null if checksum not exists for line
039       */
040      public static String getChecksumForLine(List<String> checksums, Integer line) {
041        if (line == null || line < 1 || line > checksums.size()) {
042          return null;
043        }
044        return checksums.get(line - 1);
045      }
046    
047      public static List<String> lineChecksumsOfFile(String file) {
048        List<String> result = Lists.newArrayList();
049        if (file != null) {
050          String[] lines = file.split("\r?\n|\r", -1);
051          for (String line : lines) {
052            result.add(lineChecksum(line));
053          }
054        }
055        return result;
056      }
057    
058      public static String lineChecksum(String line) {
059        String reducedLine = StringUtils.replaceChars(line, SPACE_CHARS, "");
060        return DigestUtils.md5Hex(reducedLine);
061      }
062    
063    }