SyndDateUtils.java

package de.danoeh.antennapodsp.syndication.util;

import android.util.Log;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

/**
 * Parses several date formats.
 */
public class SyndDateUtils {
    private static final String TAG = "DateUtils";

    private static final String[] RFC822DATES = {"dd MMM yy HH:mm:ss Z",};

    /**
     * RFC 3339 date format for UTC dates.
     */
    public static final String RFC3339UTC = "yyyy-MM-dd'T'HH:mm:ss'Z'";

    /**
     * RFC 3339 date format for localtime dates with offset.
     */
    public static final String RFC3339LOCAL = "yyyy-MM-dd'T'HH:mm:ssZ";

    private static ThreadLocal<SimpleDateFormat> RFC822Formatter = new ThreadLocal<SimpleDateFormat>() {
        @Override
        protected SimpleDateFormat initialValue() {
            return new SimpleDateFormat(RFC822DATES[0], Locale.US);
        }

    };

    private static ThreadLocal<SimpleDateFormat> RFC3339Formatter = new ThreadLocal<SimpleDateFormat>() {
        @Override
        protected SimpleDateFormat initialValue() {
            return new SimpleDateFormat(RFC3339UTC, Locale.US);
        }

    };

    public static Date parseRFC822Date(String date) {
        Date result = null;
        if (date.contains("PDT")) {
            date = date.replace("PDT", "PST8PDT");
        }
        if (date.contains(",")) {
            // Remove day of the week
            date = date.substring(date.indexOf(",") + 1).trim();
        }
        SimpleDateFormat format = RFC822Formatter.get();
        for (int i = 0; i < RFC822DATES.length; i++) {
            try {
                format.applyPattern(RFC822DATES[i]);
                result = format.parse(date);
                break;
            } catch (ParseException e) {
                e.printStackTrace();
            }
        }
        if (result == null) {
            Log.e(TAG, "Unable to parse feed date correctly");
        }

        return result;
    }

    public static Date parseRFC3339Date(String date) {
        Date result = null;
        SimpleDateFormat format = RFC3339Formatter.get();
        boolean isLocal = date.endsWith("Z");
        if (date.contains(".")) {
            // remove secfrac
            int fracIndex = date.indexOf(".");
            String first = date.substring(0, fracIndex);
            String second = null;
            if (isLocal) {
                second = date.substring(date.length() - 1);
            } else {
                if (date.contains("+")) {
                    second = date.substring(date.indexOf("+"));
                } else {
                    second = date.substring(date.indexOf("-"));
                }
            }

            date = first + second;
        }
        if (isLocal) {
            try {
                result = format.parse(date);
            } catch (ParseException e) {
                e.printStackTrace();
            }
        } else {
            format.applyPattern(RFC3339LOCAL);
            // remove last colon
            StringBuffer buf = new StringBuffer(date.length() - 1);
            int colonIdx = date.lastIndexOf(':');
            for (int x = 0; x < date.length(); x++) {
                if (x != colonIdx)
                    buf.append(date.charAt(x));
            }
            String bufStr = buf.toString();
            try {
                result = format.parse(bufStr);
            } catch (ParseException e) {
                e.printStackTrace();
                Log.e(TAG, "Unable to parse date");
            } finally {
                format.applyPattern(RFC3339UTC);
            }

        }

        return result;

    }

    /**
     * Takes a string of the form [HH:]MM:SS[.mmm] and converts it to
     * milliseconds.
     */
    public static long parseTimeString(final String time) {
        String[] parts = time.split(":");
        long result = 0;
        int idx = 0;
        if (parts.length == 3) {
            // string has hours
            result += Integer.valueOf(parts[idx]) * 3600000L;
            idx++;
        }
        result += Integer.valueOf(parts[idx]) * 60000L;
        idx++;
        result += (Float.valueOf(parts[idx])) * 1000L;
        return result;
    }
}