Question

I have very irregular dates like:

Mon, 9 Jan 2012 14:18:32 -0800 (GMT)

18 Oct 2006 00:32:03 -0000

Sat, 18 Nov 2006 19:52:23 UT

I made a really complex function to get it all done, it works but for the purpose of learning i want to do it again with using try and catch.
My question is, how can i deal with the timezone? You can see all the timezone’s in my function, however i also have sometime (… as a timezone for example and i don’t want to store all cases in a String array.

Also i want to use Joda-Time, (it can be localDate or dateTime, doesn’t matter that much to me).

public LocalDate handleDate(String date) {

        String[] days = { "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun" };
        String[] months = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul",
                "Aug", "Sep", "Oct", "Nov", "Dec" };
        String[] years = { "2004", "2005", "2006", "2007", "2008", "2009",
                "2010", "2011", "2012" };

        // ORDER IS VERRY IMPORTANT!! ( MEST must be before EST for example)
        String[] timesZones = { "BST", "CET", "CEST", "CST", "CDT", "EDT",
                "GMT+00:00", "GMT", "IST", "MEST", "EST", "MET", "MDT", "PST",
                "PDT", "SAST", "UTC", "UT", "W. Europe Standard Time",
                "West-Europa (zomertijd)" };

        String origDate = date;

        String timeZone = "";
        String year = "";
        String month = "";
        String day = "";
        int hours = 0;
        int minutes = 0;
        int seconds = 0;

        // is it valid?
        date = trim(date);
        if (date.equals("")) {
            return null;
        }

        // first delete the comma that comes mostly after the day
        date = date.replaceAll(",", "");

        // remove the day
        for (int i = 0; i < days.length; i++) {
            if (date.contains(days[i])) {
                date = date.replace(days[i], "");
                break;
            }
        }

        // if(date.contains("23:27:17")) println(date);

        for (int i = 0; i < timesZones.length; i++) {
            // first check with '(' and ')'
            String target = "(" + timesZones[i] + ")";

            if (date.contains(target)) {
                timeZone = timesZones[i];
                date = date.replace(target, "");
                break;
            }

            // if not found check without '(' and ')'
            if (date.contains(timesZones[i])) {
                timeZone = timesZones[i];
                date = date.replace(timesZones[i], "");
                break;
            }
        }

        // get the month
        for (int i = 0; i < months.length; i++) {
            if (date.contains(months[i])) {
                month = months[i].toLowerCase(); // !must be lowercase
                // must be dutch on my pc
                if (month.equals("oct"))
                    month = "okt";
                if (month.equals("may"))
                    month = "mei";
                if (month.equals("mar"))
                    month = "mrt";

                date = date.replace(months[i], "");
                break;
            }
        }

        // get the year
        for (int i = 0; i < years.length; i++) {
            if (date.contains(years[i])) {
                year = years[i];
                date = date.replace(years[i], "");
                break;
            }
        }

        // get the time
        Pattern p = Pattern.compile("(\\d\\d):(\\d\\d):(\\d\\d)");
        Matcher m = p.matcher(date);
        if (m.find()) {
            // also fix the time, 00 is not allowed

            hours = Integer.parseInt(m.group(1));
            minutes = Integer.parseInt(m.group(2));
            seconds = Integer.parseInt(m.group(3));

            date = date.replaceAll("(\\d\\d:\\d\\d:\\d\\d)", "");
        }

        // get the time difference
        date = date.replace("+-", "+0"); // bug fix where data is incorrect ( 16
                                            // Sep 2007 23:27:17 +-200)

        p = Pattern.compile("[+|-]*(\\d\\d)\\d\\d");
        m = p.matcher(date);
        if (m.find()) {
            int timeDifferenceH = Integer.parseInt(m.group(1));

            date = date.replaceAll("([+|-]*\\d\\d\\d\\d)", "");
        }

        date = " " + date; // bug fix

        // get the day
        for (int i = 31; i >= 1; i--) {
            // first check for the ones that contains 2 digits (like 07)
            String d = nf(i, 2);
            if (date.contains(d)) {
                day = nf(i, 2);
                date = date.replace(d, "");
                break;
            }

            // check for 1 digit
            d = "" + i;
            if (date.contains(d)) {
                day = nf(i, 2);
                date = date.replace(d, "");
                break;
            }
        }

        // there should be nothing left except white space
        date = date.replace(" ", "");
        if (date.equals("") == false) {
            println("handleDate: problem with input\n" + date);
            println(origDate + "\n");
            println(year);
            println(month);
            println(day);
        }

        // String cleanDate = day + "/" + month + "/" + year + " " + nf(hours,
        // 2) + ":" + nf(minutes, 2) + ":" + nf(seconds, 2);
        // DateTimeFormatter formatter =
        // DateTimeFormat.forPattern("dd/MMM/yyyy HH:mm:ss");

        String cleanDate = year + "-" + month + "-" + day;
        DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MMM-dd");

        try {

            // DateTime dt = formatter.parseDateTime(cleanDate);
            // LocalDate dt = new LocalDate(cleanDate);
            // return dt.toLocalDate();
            // return dt;
            // return new LocalDate().parse(cleanDate, formatter);
            return formatter.parseLocalDate(cleanDate);
        } catch (IllegalArgumentException iae) {
            println("handleDate: Problem with formatting: " + cleanDate);
        }

        return null;
    }

Answer 1

The DateTimeFormatter class in JodaTime is quite strong and flexible in this, you should try Custom Formatters or Freaky Formatters