Elevator Maintenance

import java.util.Arrays;
import java.util.Comparator;

class Solution implements Comparator<String> {
  @Override
  public int compare(String version1, String version2) {

    //separates by major, minor and revision types
    String[] v1 = version1.split("\\.");
    String[] v2 = version2.split("\\.");

    //saves number of both versions
    int major1 = major(v1);
    int major2 = major(v2);
    Integer minor1 = minor(v1);
    Integer minor2 = minor(v2);
    Integer revision1 = revision(v1);
    Integer revision2= revision(v2);

    //returns the bigger version
    if (major1 == major2) {
        if (minor1 == minor2) {
          return revision1.compareTo(revision2);
        }
      return minor1.compareTo(minor2);
    }
    return major1 > major2 ? 1 : -1;
  }

  //returns the major
  private int major(String[] version) {
    return Integer.parseInt(version[0]);
  }

  //returns the minor
  private Integer minor(String[] version) {
    return version.length > 1 ? Integer.parseInt(version[1]) : -1;
  }

  //returns the revision
  private Integer revision(String[] version) {
      return version.length > 2 ? Integer.parseInt(version[2]) : -1;
  }

    public static String[] solution(String[] l) {
        Arrays.sort(l, new Solution());
        return l;
    }

}