How to use

SimpleDateFormat

in

java.text

public boolean isDateExpired(String input, Date expiration) throws ParseException {
 DateFormat dateFormat = new SimpleDateFormat ("dd/MM/yyyy");
 Date date = dateFormat.parse(input);
 return date.after(expiration);
}

 SimpleDateFormat dateFormatGmt = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
dateFormatGmt.setTimeZone(TimeZone.getTimeZone("GMT"));

//Local time zone   
SimpleDateFormat dateFormatLocal = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");

//Time in GMT
return dateFormatLocal.parse( dateFormatGmt.format(new Date()) );

static String timeAsGmt() {
 SimpleDateFormat sdf = new SimpleDateFormat();
 sdf.setTimeZone(TimeZone.getTimeZone("GMT"));
 sdf.applyPattern("dd MMM yyyy HH:mm:ss z");
 return sdf.format(Calendar.getInstance().getTime());
}

  @Override
  public Object decode(Object jv) throws IOException {
    if (jv instanceof String) {
      try {
        return new SimpleDateFormat(DATE_FORMAT).parse((String) jv);
      } catch (ParseException e) {
        throw new IllegalArgumentException(e.getMessage(), e);
      }
    }
    if (jv instanceof Number) {
      return new Date(((Number) jv).longValue());
    }
    return (Date) null;
  }
};

private DateFormat newDateFormat() {
  SimpleDateFormat dateFormat = new SimpleDateFormat(DATE_FORMAT, Locale.US);
  dateFormat.setTimeZone(GMT);
  return dateFormat;
}

public static String toString(java.util.Date date) {
  if (date == null) {
    return null;
  }
  SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
  return format.format(date);
}

private long parseDateHeader(String name, String value) {
  for (String dateFormat : DATE_FORMATS) {
    SimpleDateFormat simpleDateFormat = new SimpleDateFormat(dateFormat, Locale.US);
    simpleDateFormat.setTimeZone(GMT);
    try {
      return simpleDateFormat.parse(value).getTime();
    }
    catch (ParseException ex) {
      // ignore
    }
  }
  throw new IllegalArgumentException("Cannot parse date value '" + value + "' for '" + name + "' header");
}

 // Create an instance of SimpleDateFormat used for formatting 
// the string representation of date (month/day/year)
DateFormat df = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");

// Get the date today using Calendar object.
Date today = Calendar.getInstance().getTime();        
// Using DateFormat format method we can create a string 
// representation of a date with the defined format.
String reportDate = df.format(today);

// Print what date is today!
System.out.println("Report Date: " + reportDate);

private void printStartInfo() {
  Date currentDate = new Date();
  Calendar calendar = Calendar.getInstance();
  calendar.setTime(currentDate);
  calendar.add(Calendar.SECOND, runTime);
  Date finishDate = calendar.getTime();
  StringBuilder startInfo = new StringBuilder(dateFormat.format(currentDate));
  startInfo.append(" ready to start client benchmark");
  startInfo.append(", concurrent num is ").append(concurrents);
  startInfo.append(", the benchmark will end at ").append(dateFormat.format(finishDate));
  System.out.println(startInfo.toString());
}

/**
 * Sets the Date and Cache headers for the HTTP Response
 *
 * @param response
 *            HTTP response
 * @param fileToCache
 *            file to extract content type
 */
private static void setDateAndCacheHeaders(io.netty.handler.codec.http.HttpResponse response, File fileToCache) {
  SimpleDateFormat dateFormatter = new SimpleDateFormat(HTTP_DATE_FORMAT, Locale.US);
  dateFormatter.setTimeZone(TimeZone.getTimeZone(HTTP_DATE_GMT_TIMEZONE));
  // Date header
  Calendar time = new GregorianCalendar();
  response.headers().set(DATE, dateFormatter.format(time.getTime()));
  // Add cache headers
  time.add(Calendar.SECOND, HTTP_CACHE_SECONDS);
  response.headers()
      .set(EXPIRES, dateFormatter.format(time.getTime()))
      .set(CACHE_CONTROL, "private, max-age=" + HTTP_CACHE_SECONDS)
      .set(LAST_MODIFIED, dateFormatter.format(new Date(fileToCache.lastModified())));
}

public static List<String> getOldWeekDays() {
  final Calendar c = Calendar.getInstance();
  String[] months = new String[8];
  for (int i = 0; i < 8; i++) {
    months[i] = new SimpleDateFormat("MM.dd").format(new Date(c
        .getTimeInMillis()));
    c.add(Calendar.DAY_OF_MONTH, -1);
  }
  return Arrays.asList(months);
}

 Calendar c = Calendar.getInstance();
c.setTime(new Date(yourmilliseconds));
c.set(Calendar.MILLISECOND, 0);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm.ss.SSS'Z'");
sdf.setTimeZone(TimeZone.getTimeZone("GMT"));
System.out.println(sdf.format(c.getTime()));

 Date now = new Date(); // java.util.Date, NOT java.sql.Date or java.sql.Timestamp!
String format1 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS", Locale.ENGLISH).format(now);
String format2 = new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z", Locale.ENGLISH).format(now);
String format3 = new SimpleDateFormat("yyyyMMddHHmmss", Locale.ENGLISH).format(now);

System.out.println(format1);
System.out.println(format2);
System.out.println(format3);

  private String getTimeoutMessage(boolean scan) {
    long nowTimestamp = System.currentTimeMillis();
    return (sent > 0 ? "Waiting server-side response timeout" : "Sending request timeout in client-side")
        + (scan ? " by scan timer" : "") + ". start time: "
        + (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS").format(new Date(start))) + ", end time: "
        + (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS").format(new Date())) + ","
        + (sent > 0 ? " client elapsed: " + (sent - start)
        + " ms, server elapsed: " + (nowTimestamp - sent)
        : " elapsed: " + (nowTimestamp - start)) + " ms, timeout: "
        + timeout + " ms, request: " + request + ", channel: " + channel.getLocalAddress()
        + " -> " + channel.getRemoteAddress();
  }
}

UTC = TimeZone.getTimeZone("UTC");
TimeZone.setDefault(UTC);
final Calendar c = new GregorianCalendar(UTC);
c.set(1, 0, 1, 0, 0, 0);
c.set(Calendar.MILLISECOND, 0);
BEGINNING_OF_TIME = c.getTime();
c.setTime(new Date(Long.MAX_VALUE));
END_OF_TIME = c.getTime();
final SimpleDateFormat sdf = new SimpleDateFormat(ISO_8601_24H_FULL_FORMAT);
sdf.setTimeZone(UTC);
System.out.println("sdf.format(BEGINNING_OF_TIME) = " + sdf.format(BEGINNING_OF_TIME));
System.out.println("sdf.format(END_OF_TIME) = " + sdf.format(END_OF_TIME));
System.out.println("sdf.format(new Date()) = " + sdf.format(new Date()));
System.out.println("sdf.parse(\"2015-04-28T14:23:38.521Z\") = " + sdf.parse("2015-04-28T14:23:38.521Z"));
System.out.println("sdf.parse(\"0001-01-01T00:00:00.000Z\") = " + sdf.parse("0001-01-01T00:00:00.000Z"));

public String getCurTime() {
  String fromTimeZone = "GMT+8";
  SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
  Date date = new Date();
  format.setTimeZone(TimeZone.getTimeZone(fromTimeZone));
  String chinaDate = format.format(date);
  return chinaDate;
}

/**
 * Sets the Date header for the HTTP response
 *
 * @param response
 *            HTTP response
 */
private static void setDateHeader(FullHttpResponse response) {
  SimpleDateFormat dateFormatter = new SimpleDateFormat(HTTP_DATE_FORMAT, Locale.US);
  dateFormatter.setTimeZone(TimeZone.getTimeZone(HTTP_DATE_GMT_TIMEZONE));
  Calendar time = new GregorianCalendar();
  response.headers().set(DATE, dateFormatter.format(time.getTime()));
}

 final DateFormat format = new SimpleDateFormat("E. M/d");
final String dateStr = "Thu. 03/01";
final Date date = format.parse(dateStr);

GregorianCalendar gregory = new GregorianCalendar();
gregory.setTime(date);

XMLGregorianCalendar calendar = DatatypeFactory.newInstance()
    .newXMLGregorianCalendar(
      gregory);

@Test
public void testCalendar() {
  Date d = new Date(0);
  Calendar cal = Calendar.getInstance();
  cal.setTime(d);
  assertThat(jdkTypeToJson(cal), containsString(new SimpleDateFormat("yyyy-MM-dd").format(d)));
}

protected List<TimePeriod> parseHolidays() {
  String holidaysString = businessCalendarConfiguration.getProperty(HOLIDAYS);
  List<TimePeriod> holidays = new ArrayList<TimePeriod>();
  int currentYear = Calendar.getInstance().get(Calendar.YEAR);
  if (holidaysString != null) {
    String[] hPeriods = holidaysString.split(",");
    SimpleDateFormat sdf = new SimpleDateFormat(businessCalendarConfiguration.getProperty(HOLIDAY_DATE_FORMAT, "yyyy-MM-dd"));
    for (String hPeriod : hPeriods) {
      boolean addNextYearHolidays = false;
          Calendar tmpFrom = new GregorianCalendar();
          if (timezone != null) {
            tmpFrom.setTimeZone(TimeZone.getTimeZone(timezone));
          tmpFrom.setTime(sdf.parse(fromTo[0]));
          tmpTo.setTime(sdf.parse(fromTo[1]));
            tmpFrom.setTime(sdf.parse(fromTo[0]));
            tmpTo.setTime(sdf.parse(fromTo[1]));
          c.setTime(sdf.parse(fromTo[0]));
          holidays.add(new TimePeriod(sdf.parse(fromTo[0]), c.getTime()));
            tmp.setTime(sdf.parse(fromTo[0]));