LetZone from http://www.ibm.com/developerworks/java/library/j-coordconvert/

CoordinateConversion.java

private class LatZones
  {
    private char[] letters = { 'A', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K',
        'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Z' };

    private int[] degrees = { -90, -84, -72, -64, -56, -48, -40, -32, -24, -16,
        -8, 0, 8, 16, 24, 32, 40, 48, 56, 64, 72, 84 };

    private char[] negLetters = { 'A', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K',
        'L', 'M' };

    private int[] negDegrees = { -90, -84, -72, -64, -56, -48, -40, -32, -24,
        -16, -8 };

    private char[] posLetters = { 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
        'X', 'Z' };

    private int[] posDegrees = { 0, 8, 16, 24, 32, 40, 48, 56, 64, 72, 84 };

    private int arrayLength = 22;

    public LatZones()
    {
    }

    public int getLatZoneDegree(String letter)
    {
      char ltr = letter.charAt(0);
      for (int i = 0; i < arrayLength; i++)
      {
        if (letters[i] == ltr)
        {
          return degrees[i];
        }
      }
      return -100;
    }

    public String getLatZone(double latitude)
    {
      int latIndex = -2;
      int lat = (int) latitude;

      if (lat >= 0)
      {
        int len = posLetters.length;
        for (int i = 0; i < len; i++)
        {
          if (lat == posDegrees[i])
          {
            latIndex = i;
            break;
          }

          if (lat > posDegrees[i])
          {
            continue;
          }
          else
          {
            latIndex = i - 1;
            break;
          }
        }
      }
      else
      {
        int len = negLetters.length;
        for (int i = 0; i < len; i++)
        {
          if (lat == negDegrees[i])
          {
            latIndex = i;
            break;
          }

          if (lat < negDegrees[i])
          {
            latIndex = i - 1;
            break;
          }
          else
          {
            continue;
          }

        }

      }

      if (latIndex == -1)
      {
        latIndex = 0;
      }
      if (lat >= 0)
      {
        if (latIndex == -2)
        {
          latIndex = posLetters.length - 1;
        }
        return String.valueOf(posLetters[latIndex]);
      }
      else
      {
        if (latIndex == -2)
        {
          latIndex = negLetters.length - 1;
        }
        return String.valueOf(negLetters[latIndex]);

      }
    }

  }