package com.bradmcevoy.http; import java.text.DateFormat; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Arrays; import java.util.Calendar; import java.util.Collection; import java.util.Date; import java.util.Iterator; import java.util.Locale; import java.util.TimeZone; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * A utility class for parsing and formatting HTTP dates as used in cookies and * other headers. This class handles dates as defined by RFC 2616 section * 3.3.1 as well as some other common non-standard formats. * * @author Christopher Brown * @author Michael Becke */ public class DateUtils { private static final Logger log = LoggerFactory.getLogger(DateUtils.class); // 2005-03-30T05:18:33Z public static final String PATTERN_WEBDAV = "yyyy-MM-dd HH:mm:ss"; /** * Used for response headers, and for modified date in propfind */ public static final String PATTERN_RESPONSE_HEADER = "E, dd MMM yyyy HH:mm:ss z"; //public static final String PATTERN_RESPONSE_HEADER = "E MMM yyyy H:m:s z"; private static final ThreadLocal<DateFormat> thHeaderDateFormat = new ThreadLocal<DateFormat>(); /** * Date format pattern used to parse HTTP date headers in RFC 1123 format. */ public static final String PATTERN_RFC1123 = "EEE, dd MMM yyyy HH:mm:ss zzz"; /** * Date format pattern used to parse HTTP date headers in RFC 1123 format. */ public static final String PATTERN_RFC1123_NOSECS = "EEE, dd MMM yyyy HH:mm zzz"; /** * Date format pattern used to parse HTTP date headers in RFC 1036 format. */ public static final String PATTERN_RFC1036 = "EEEE, dd-MMM-yy HH:mm:ss zzz"; /** * Date format pattern used to parse HTTP date headers in ANSI C * <code>asctime()</code> format. */ public static final String PATTERN_ASCTIME = "EEE MMM d HH:mm:ss yyyy"; /** * Another Date format pattern used to parse HTTP date headers in ANSI C * <code>asctime()</code> format. */ public static final String PATTERN_ASCTIME2 = "EEE MMM yyyy HH:mm:ss zzz"; private static final Collection<String> DEFAULT_PATTERNS = Arrays.asList( new String[] { PATTERN_ASCTIME, PATTERN_ASCTIME2, PATTERN_RFC1036, PATTERN_RFC1123, PATTERN_RFC1123_NOSECS,PATTERN_WEBDAV } ); private static final Date DEFAULT_TWO_DIGIT_YEAR_START; static { Calendar calendar = Calendar.getInstance(); calendar.set(2000, Calendar.JANUARY, 1, 0, 0); DEFAULT_TWO_DIGIT_YEAR_START = calendar.getTime(); } public static final TimeZone GMT = TimeZone.getTimeZone("GMT"); /** * Parses a date value. The formats used for parsing the date value are retrieved from * the default http params. * * @param dateValue the date value to parse * * @return the parsed date * * @throws DateParseException if the value could not be parsed using any of the * supported date formats */ public static Date parseDate(String dateValue) throws DateParseException { return parseDate(dateValue, null, null); } /** * Parses the date value using the given date formats. * * @param dateValue the date value to parse * @param dateFormats the date formats to use * * @return the parsed date * * @throws DateParseException if none of the dataFormats could parse the dateValue */ public static Date parseDate(String dateValue, Collection<String> dateFormats) throws DateParseException { return parseDate(dateValue, dateFormats, null); } /** * Parses the date value using the given date formats. * * @param dateValue the date value to parse * @param dateFormats the date formats to use * @param startDate During parsing, two digit years will be placed in the range * <code>startDate</code> to <code>startDate + 100 years</code>. This value may * be <code>null</code>. When <code>null</code> is given as a parameter, year * <code>2000</code> will be used. * * @return the parsed date * * @throws DateParseException if none of the dataFormats could parse the dateValue */ public static Date parseDate( String dateValue, Collection<String> dateFormats, Date startDate ) throws DateParseException { if (dateValue == null) { throw new IllegalArgumentException("dateValue is null"); } if (dateFormats == null) { dateFormats = DEFAULT_PATTERNS; } if (startDate == null) { startDate = DEFAULT_TWO_DIGIT_YEAR_START; } // trim single quotes around date if present // see issue #5279 if (dateValue.length() > 1 && dateValue.startsWith("'") && dateValue.endsWith("'") ) { dateValue = dateValue.substring(1, dateValue.length() - 1); } SimpleDateFormat dateParser = null; Iterator<String> formatIter = dateFormats.iterator(); while (formatIter.hasNext()) { String format = formatIter.next(); if (dateParser == null) { dateParser = new SimpleDateFormat(format, Locale.US); dateParser.setTimeZone(TimeZone.getTimeZone("GMT")); dateParser.set2DigitYearStart(startDate); } else { dateParser.applyPattern(format); } try { Date dt = dateParser.parse(dateValue); return dt; } catch (ParseException pe) { // ignore this exception, we will try the next format } } // we were unable to parse the date throw new DateParseException("Unable to parse the date " + dateValue); } public static String formatDate(Date date) { Calendar cal = Calendar.getInstance(); cal.setTime(date); return formatDate(cal); } /** * * @see #PATTERN_WEBDAV */ public static String formatDate(Calendar cal) { // 2005-03-30T05:18:33Z StringBuilder sb = new StringBuilder(); sb.append( cal.get(Calendar.YEAR)+"" ); sb.append('-'); sb.append( pad2(cal.get(Calendar.MONTH)+1) ); sb.append('-'); sb.append( pad2(cal.get(Calendar.DAY_OF_MONTH)) ); // sb.append('-'); // sb.append( pad2(cal.get(Calendar.DAY_OF_MONTH)) ); // sb.append('-'); // sb.append( pad2(cal.get(Calendar.MONTH)) ); sb.append('T'); sb.append( pad2(cal.get(Calendar.HOUR_OF_DAY)) ); sb.append(':'); sb.append( pad2(cal.get(Calendar.MINUTE)) ); sb.append(':'); sb.append( pad2(cal.get(Calendar.SECOND)) ); sb.append('Z'); String s = sb.toString(); // log.debug(date.toString() + " -> " + s); return s; } public static String formatForHeader(Date date) { DateFormat df = thHeaderDateFormat.get(); if( df == null ) { df = new SimpleDateFormat(DateUtils.PATTERN_RESPONSE_HEADER); df.setTimeZone(TimeZone.getTimeZone("GMT")); thHeaderDateFormat.set( df ); } return df.format(date); } public static String pad2(int i) { if( i < 10 ) { return "0" + i; } else { return i+""; } } /** * Formats the given date according to the specified pattern. The pattern * must conform to that used by the {@link SimpleDateFormat simple date * format} class. * * @param date The date to format. * @param pattern The pattern to use for formatting the date. * @return A formatted date string. * * @throws IllegalArgumentException If the given date pattern is invalid. * * @see SimpleDateFormat */ public static String formatDate(Date date, String pattern) { if (date == null) throw new IllegalArgumentException("date is null"); if (pattern == null) throw new IllegalArgumentException("pattern is null"); SimpleDateFormat formatter = new SimpleDateFormat(pattern, Locale.US); formatter.setTimeZone(GMT); return formatter.format(date); } public static String formatForWebDavModifiedDate(Date date) { return formatDate(date,PATTERN_RFC1123); } /** This class should not be instantiated. */ private DateUtils() { } public static class DateParseException extends Exception { static final long serialVersionUID = 4417696455000643370L; /** * */ public DateParseException() { super(); } /** * @param message the exception message */ public DateParseException(String message) { super(message); } } }