/*
* Copyright 2004 Sun Microsystems, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package com.sun.syndication.io.impl;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.text.ParsePosition;
import java.util.Date;
import java.util.TimeZone;
import java.util.Locale;
/**
* A helper class that parses Dates out of Strings with date time in RFC822 and W3CDateTime
* formats plus the variants Atom (0.3) and RSS (0.9, 0.91, 0.92, 0.93, 0.94, 1.0 and 2.0)
* specificators added to those formats.
* <p/>
* It uses the JDK java.text.SimpleDateFormat class attemtping the parse using a mask for
* each one of the possible formats.
* <p/>
*
* @author Alejandro Abdelnur
*
*/
public class DateParser {
private static String[] ADDITIONAL_MASKS;
static {
ADDITIONAL_MASKS = PropertiesLoader.getPropertiesLoader().getTokenizedProperty("datetime.extra.masks","|");
}
// order is like this because the SimpleDateFormat.parse does not fail with exception
// if it can parse a valid date out of a substring of the full string given the mask
// so we have to check the most complete format first, then it fails with exception
private static final String[] RFC822_MASKS = {
"EEE, dd MMM yy HH:mm:ss z",
"EEE, dd MMM yy HH:mm z",
"dd MMM yy HH:mm:ss z",
"dd MMM yy HH:mm z"
};
// order is like this because the SimpleDateFormat.parse does not fail with exception
// if it can parse a valid date out of a substring of the full string given the mask
// so we have to check the most complete format first, then it fails with exception
private static final String[] W3CDATETIME_MASKS = {
"yyyy-MM-dd'T'HH:mm:ss.SSSz",
"yyyy-MM-dd't'HH:mm:ss.SSSz",
"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'",
"yyyy-MM-dd't'HH:mm:ss.SSS'z'",
"yyyy-MM-dd'T'HH:mm:ssz",
"yyyy-MM-dd't'HH:mm:ssz",
"yyyy-MM-dd'T'HH:mm:ss'Z'",
"yyyy-MM-dd't'HH:mm:ss'z'",
"yyyy-MM-dd'T'HH:mmz", // together with logic in the parseW3CDateTime they
"yyyy-MM'T'HH:mmz", // handle W3C dates without time forcing them to be GMT
"yyyy'T'HH:mmz",
"yyyy-MM-dd't'HH:mmz",
"yyyy-MM-dd'T'HH:mm'Z'",
"yyyy-MM-dd't'HH:mm'z'",
"yyyy-MM-dd",
"yyyy-MM",
"yyyy"
};
/**
* The masks used to validate and parse the input to this Atom date.
* These are a lot more forgiving than what the Atom spec allows.
* The forms that are invalid according to the spec are indicated.
*/
private static final String[] masks = {
"yyyy-MM-dd'T'HH:mm:ss.SSSz",
"yyyy-MM-dd't'HH:mm:ss.SSSz", // invalid
"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'",
"yyyy-MM-dd't'HH:mm:ss.SSS'z'", // invalid
"yyyy-MM-dd'T'HH:mm:ssz",
"yyyy-MM-dd't'HH:mm:ssz", // invalid
"yyyy-MM-dd'T'HH:mm:ss'Z'",
"yyyy-MM-dd't'HH:mm:ss'z'", // invalid
"yyyy-MM-dd'T'HH:mmz", // invalid
"yyyy-MM-dd't'HH:mmz", // invalid
"yyyy-MM-dd'T'HH:mm'Z'", // invalid
"yyyy-MM-dd't'HH:mm'z'", // invalid
"yyyy-MM-dd",
"yyyy-MM",
"yyyy"
};
/**
* Private constructor to avoid DateParser instances creation.
*/
private DateParser() {
}
/**
* Parses a Date out of a string using an array of masks.
* <p/>
* It uses the masks in order until one of them succedes or all fail.
* <p/>
*
* @param masks array of masks to use for parsing the string
* @param sDate string to parse for a date.
* @return the Date represented by the given string using one of the given masks.
* It returns <b>null</b> if it was not possible to parse the the string with any of the masks.
*
*/
private static Date parseUsingMask(String[] masks,String sDate) {
sDate = (sDate!=null) ? sDate.trim() : null;
ParsePosition pp = null;
Date d = null;
for (int i=0;d==null && i<masks.length;i++) {
DateFormat df = new SimpleDateFormat(masks[i],Locale.US);
//df.setLenient(false);
df.setLenient(true);
try {
pp = new ParsePosition(0);
d = df.parse(sDate,pp);
if (pp.getIndex()!=sDate.length()) {
d = null;
}
//System.out.println("pp["+pp.getIndex()+"] s["+sDate+" m["+masks[i]+"] d["+d+"]");
}
catch (Exception ex1) {
//System.out.println("s: "+sDate+" m: "+masks[i]+" d: "+null);
}
}
return d;
}
/**
* Parses a Date out of a String with a date in RFC822 format.
* <p/>
* It parsers the following formats:
* <ul>
* <li>"EEE, dd MMM yyyy HH:mm:ss z"</li>
* <li>"EEE, dd MMM yyyy HH:mm z"</li>
* <li>"EEE, dd MMM yy HH:mm:ss z"</li>
* <li>"EEE, dd MMM yy HH:mm z"</li>
* <li>"dd MMM yyyy HH:mm:ss z"</li>
* <li>"dd MMM yyyy HH:mm z"</li>
* <li>"dd MMM yy HH:mm:ss z"</li>
* <li>"dd MMM yy HH:mm z"</li>
* </ul>
* <p/>
* Refer to the java.text.SimpleDateFormat javadocs for details on the format of each element.
* <p/>
* @param sDate string to parse for a date.
* @return the Date represented by the given RFC822 string.
* It returns <b>null</b> if it was not possible to parse the given string into a Date.
*
*/
public static Date parseRFC822(String sDate) {
int utIndex = sDate.indexOf(" UT");
if (utIndex>-1) {
String pre = sDate.substring(0,utIndex);
String post = sDate.substring(utIndex+3);
sDate = pre + " GMT" + post;
}
return parseUsingMask(RFC822_MASKS,sDate);
}
/**
* Parses a Date out of a String with a date in W3C date-time format.
* <p/>
* It parsers the following formats:
* <ul>
* <li>"yyyy-MM-dd'T'HH:mm:ssz"</li>
* <li>"yyyy-MM-dd'T'HH:mmz"</li>
* <li>"yyyy-MM-dd"</li>
* <li>"yyyy-MM"</li>
* <li>"yyyy"</li>
* </ul>
* <p/>
* Refer to the java.text.SimpleDateFormat javadocs for details on the format of each element.
* <p/>
* @param sDate string to parse for a date.
* @return the Date represented by the given W3C date-time string.
* It returns <b>null</b> if it was not possible to parse the given string into a Date.
*
*/
public static Date parseW3CDateTime(String sDate) {
// if sDate has time on it, it injects 'GTM' before de TZ displacement to
// allow the SimpleDateFormat parser to parse it properly
int tIndex = sDate.indexOf("T");
if (tIndex>-1) {
if (sDate.endsWith("Z")) {
sDate = sDate.substring(0,sDate.length()-1)+"+00:00";
}
int tzdIndex = sDate.indexOf("+",tIndex);
if (tzdIndex==-1) {
tzdIndex = sDate.indexOf("-",tIndex);
}
if (tzdIndex>-1) {
String pre = sDate.substring(0,tzdIndex);
int secFraction = pre.indexOf(",");
if (secFraction>-1) {
pre = pre.substring(0,secFraction);
}
String post = sDate.substring(tzdIndex);
sDate = pre + "GMT" + post;
}
}
else {
sDate += "T00:00GMT";
}
return parseUsingMask(W3CDATETIME_MASKS,sDate);
}
/**
* Parses a Date out of a String with a date in W3C date-time format or
* in a RFC822 format.
* <p>
* @param sDate string to parse for a date.
* @return the Date represented by the given W3C date-time string.
* It returns <b>null</b> if it was not possible to parse the given string into a Date.
*
* */
public static Date parseDate(String sDate) {
Date d = parseW3CDateTime(sDate);
if (d==null) {
d = parseRFC822(sDate);
if (d==null && ADDITIONAL_MASKS.length>0) {
d = parseUsingMask(ADDITIONAL_MASKS,sDate);
}
}
return d;
}
/**
* create a RFC822 representation of a date.
* <p/>
* Refer to the java.text.SimpleDateFormat javadocs for details on the format of each element.
* <p/>
* @param date Date to parse
* @return the RFC822 represented by the given Date
* It returns <b>null</b> if it was not possible to parse the date.
*
*/
public static String formatRFC822(Date date) {
SimpleDateFormat dateFormater = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss 'GMT'",Locale.US);
dateFormater.setTimeZone(TimeZone.getTimeZone("GMT"));
return dateFormater.format(date);
}
/**
* create a W3C Date Time representation of a date.
* <p/>
* Refer to the java.text.SimpleDateFormat javadocs for details on the format of each element.
* <p/>
* @param date Date to parse
* @return the W3C Date Time represented by the given Date
* It returns <b>null</b> if it was not possible to parse the date.
*
*/
public static String formatW3CDateTime(Date date) {
SimpleDateFormat dateFormater = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'",Locale.US);
dateFormater.setTimeZone(TimeZone.getTimeZone("GMT"));
return dateFormater.format(date);
}
}
