Mega Code Archive
Date parser for ISO 8601 format
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// DateParser.java
// $Id: DateParser.java,v 1.5 2005/05/16 10:19:19 ylafon Exp $
// (c) COPYRIGHT MIT, INRIA and Keio, 2000.
// Please first read the full copyright statement in file COPYRIGHT.html
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.NoSuchElementException;
import java.util.StringTokenizer;
import java.util.TimeZone;
/**
* Date parser for ISO 8601 format
* http://www.w3.org/TR/1998/NOTE-datetime-19980827
*
* @version $Revision: 1.5 $
* @author Benoît Mahé (bmahe@w3.org)
* @author Yves Lafon (ylafon@w3.org)
*/
public class DateParser {
private static boolean check(StringTokenizer st, String token)
{
try {
if (st.nextToken().equals(token)) {
return true;
} else {
throw new RuntimeException("Missing [" + token + "]");
}
} catch (NoSuchElementException ex) {
return false;
}
}
private static Calendar getCalendar(String isodate) {
// YYYY-MM-DDThh:mm:ss.sTZD
StringTokenizer st = new StringTokenizer(isodate, "-T:.+Z", true);
Calendar calendar = new GregorianCalendar(TimeZone.getTimeZone("UTC"));
calendar.clear();
try {
// Year
if (st.hasMoreTokens()) {
int year = Integer.parseInt(st.nextToken());
calendar.set(Calendar.YEAR, year);
} else {
return calendar;
}
// Month
if (check(st, "-") && (st.hasMoreTokens())) {
int month = Integer.parseInt(st.nextToken()) - 1;
calendar.set(Calendar.MONTH, month);
} else {
return calendar;
}
// Day
if (check(st, "-") && (st.hasMoreTokens())) {
int day = Integer.parseInt(st.nextToken());
calendar.set(Calendar.DAY_OF_MONTH, day);
} else {
return calendar;
}
// Hour
if (check(st, "T") && (st.hasMoreTokens())) {
int hour = Integer.parseInt(st.nextToken());
calendar.set(Calendar.HOUR_OF_DAY, hour);
} else {
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
return calendar;
}
// Minutes
if (check(st, ":") && (st.hasMoreTokens())) {
int minutes = Integer.parseInt(st.nextToken());
calendar.set(Calendar.MINUTE, minutes);
} else {
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
return calendar;
}
//
// Not mandatory now
//
// Secondes
if (!st.hasMoreTokens()) {
return calendar;
}
String tok = st.nextToken();
if (tok.equals(":")) { // secondes
if (st.hasMoreTokens()) {
int secondes = Integer.parseInt(st.nextToken());
calendar.set(Calendar.SECOND, secondes);
if (!st.hasMoreTokens()) {
return calendar;
}
// frac sec
tok = st.nextToken();
if (tok.equals(".")) {
// bug fixed, thx to Martin Bottcher
String nt = st.nextToken();
while (nt.length() < 3) {
nt += "0";
}
nt = nt.substring(0, 3); // Cut trailing chars..
int millisec = Integer.parseInt(nt);
// int millisec = Integer.parseInt(st.nextToken()) * 10;
calendar.set(Calendar.MILLISECOND, millisec);
if (!st.hasMoreTokens()) {
return calendar;
}
tok = st.nextToken();
} else {
calendar.set(Calendar.MILLISECOND, 0);
}
} else {
throw new RuntimeException("No secondes specified");
}
} else {
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
}
// Timezone
if (!tok.equals("Z")) { // UTC
if (!(tok.equals("+") || tok.equals("-"))) {
throw new RuntimeException("only Z, + or - allowed");
}
boolean plus = tok.equals("+");
if (!st.hasMoreTokens()) {
throw new RuntimeException("Missing hour field");
}
int tzhour = Integer.parseInt(st.nextToken());
int tzmin = 0;
if (check(st, ":") && (st.hasMoreTokens())) {
tzmin = Integer.parseInt(st.nextToken());
} else {
throw new RuntimeException("Missing minute field");
}
if (plus) {
calendar.add(Calendar.HOUR, -tzhour);
calendar.add(Calendar.MINUTE, -tzmin);
} else {
calendar.add(Calendar.HOUR, tzhour);
calendar.add(Calendar.MINUTE, tzmin);
}
}
} catch (NumberFormatException ex) {
throw new RuntimeException("[" + ex.getMessage() + "] is not an integer");
}
return calendar;
}
/**
* Parse the given string in ISO 8601 format and build a Date object.
*
* @param isodate
* the date in ISO 8601 format
* @return a Date instance
* @exception InvalidDateException
* if the date is not valid
*/
public static Date parse(String isodate) {
Calendar calendar = getCalendar(isodate);
return calendar.getTime();
}
private static String twoDigit(int i) {
if (i >= 0 && i < 10) {
return "0" + String.valueOf(i);
}
return String.valueOf(i);
}
/**
* Generate a ISO 8601 date
*
* @param date
* a Date instance
* @return a string representing the date in the ISO 8601 format
*/
public static String getIsoDate(Date date) {
Calendar calendar = new GregorianCalendar(TimeZone.getTimeZone("UTC"));
calendar.setTime(date);
StringBuffer buffer = new StringBuffer();
buffer.append(calendar.get(Calendar.YEAR));
buffer.append("-");
buffer.append(twoDigit(calendar.get(Calendar.MONTH) + 1));
buffer.append("-");
buffer.append(twoDigit(calendar.get(Calendar.DAY_OF_MONTH)));
buffer.append("T");
buffer.append(twoDigit(calendar.get(Calendar.HOUR_OF_DAY)));
buffer.append(":");
buffer.append(twoDigit(calendar.get(Calendar.MINUTE)));
buffer.append(":");
buffer.append(twoDigit(calendar.get(Calendar.SECOND)));
buffer.append(".");
buffer.append(twoDigit(calendar.get(Calendar.MILLISECOND) / 10));
buffer.append("Z");
return buffer.toString();
}
/**
* Generate a ISO 8601 date
*
* @param date
* a Date instance
* @return a string representing the date in the ISO 8601 format
*/
public static String getIsoDateNoMillis(Date date) {
Calendar calendar = new GregorianCalendar(TimeZone.getTimeZone("UTC"));
calendar.setTime(date);
StringBuffer buffer = new StringBuffer();
buffer.append(calendar.get(Calendar.YEAR));
buffer.append("-");
buffer.append(twoDigit(calendar.get(Calendar.MONTH) + 1));
buffer.append("-");
buffer.append(twoDigit(calendar.get(Calendar.DAY_OF_MONTH)));
buffer.append("T");
buffer.append(twoDigit(calendar.get(Calendar.HOUR_OF_DAY)));
buffer.append(":");
buffer.append(twoDigit(calendar.get(Calendar.MINUTE)));
buffer.append(":");
buffer.append(twoDigit(calendar.get(Calendar.SECOND)));
buffer.append("Z");
return buffer.toString();
}
public static void test(String isodate) {
System.out.println("----------------------------------");
Date date = parse(isodate);
System.out.println(">> " + isodate);
System.out.println(">> " + date.toString() + " [" + date.getTime() + "]");
System.out.println(">> " + getIsoDate(date));
System.out.println("----------------------------------");
}
public static void test(Date date) {
String isodate = null;
System.out.println("----------------------------------");
System.out.println(">> " + date.toString() + " [" + date.getTime() + "]");
isodate = getIsoDate(date);
System.out.println(">> " + isodate);
date = parse(isodate);
System.out.println(">> " + date.toString() + " [" + date.getTime() + "]");
System.out.println("----------------------------------");
}
public static void main(String args[]) {
test("1997-07-16T19:20:30.45-02:00");
test("1997-07-16T19:20:30+01:00");
test("1997-07-16T19:20:30+01:00");
test("1997-07-16T12:20:30-06:00");
test("1997-07-16T19:20");
test("1997-07-16");
test("1997-07");
test("1997");
test(new Date());
}
}
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