PatternDecoder.java

/*
 * Sonar Switch Off Violations Plugin
 * Copyright (C) 2011 SonarSource
 * dev@sonar.codehaus.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
 */

package org.sonar.plugins.switchoffviolations;

import com.google.common.collect.Lists;
import org.apache.commons.io.FileUtils;
import org.apache.commons.lang.StringUtils;
import org.sonar.api.utils.SonarException;

import java.io.File;
import java.io.IOException;
import java.util.List;

final class PatternDecoder {

  static final String LINE_RANGE_REGEXP = "\\[((\\d+|\\d+-\\d+),?)*\\]";

  Pattern decodeLine(String line) {
    if (isBlankOrComment(line)) {
      return null;
    }

    String[] fields = StringUtils.split(line, ';');
    if (fields.length != 3) {
      throw new SonarException("Unvalid format. The following line does not define 3 fields separated by comma: " + line);
    }

    if (!isResource(fields[0])) {
      throw new SonarException("Unvalid format. The first field does not define a resource pattern: " + line);
    }
    if (!isRule(fields[1])) {
      throw new SonarException("Unvalid format. The second field does not define a rule pattern: " + line);
    }
    if (!isLinesRange(fields[2])) {
      throw new SonarException("Unvalid format. The third field does not define a range of lines: " + line);
    }

    Pattern pattern = new Pattern(StringUtils.trim(fields[0]), StringUtils.trim(fields[1]));
    decodeRangeOfLines(pattern, fields[2]);

    return pattern;
  }

  void decodeRangeOfLines(Pattern pattern, String field) {
    if (StringUtils.equals(field, "*")) {
      pattern.setCheckLines(false);
    } else {
      pattern.setCheckLines(true);
      String s = StringUtils.substringBetween(StringUtils.trim(field), "[", "]");
      String[] parts = StringUtils.split(s, ',');
      for (String part : parts) {
        if (StringUtils.contains(part, '-')) {
          String[] range = StringUtils.split(part, '-');
          pattern.addLineRange(Integer.valueOf(range[0]), Integer.valueOf(range[1]));
        } else {
          pattern.addLine(Integer.valueOf(part));
        }
      }
    }
  }

  boolean isLinesRange(String field) {
    return StringUtils.equals(field, "*") || java.util.regex.Pattern.matches(LINE_RANGE_REGEXP, field);
  }

  boolean isBlankOrComment(String line) {
    return StringUtils.isBlank(line) || StringUtils.startsWith(line, "#");
  }

  boolean isResource(String field) {
    return StringUtils.isNotBlank(field);
  }

  boolean isRule(String field) {
    return StringUtils.isNotBlank(field);
  }

  List<Pattern> decodeFile(File file) {
    try {
      List<String> lines = FileUtils.readLines(file);
      List<Pattern> patterns = Lists.newLinkedList();
      for (String line : lines) {
        Pattern pattern = decodeLine(line);
        if (pattern != null) {
          patterns.add(pattern);
        }
      }
      return patterns;

    } catch (IOException e) {
      throw new SonarException("Fail to load the file: " + file.getAbsolutePath(), e);
    }
  }
}