package org.openstreetmap.josm.tools;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
/**
* Handles a number of different date formats encountered in OSM. This is built
* based on similar code in JOSM. This class is not threadsafe, a separate
* instance must be created per thread.
*
* @author Brett Henderson
*/
public class FallbackDateParser {
private static final String[] formats = {
"yyyy-MM-dd'T'HH:mm:ss'Z'",
"yyyy-MM-dd'T'HH:mm:ssZ",
"yyyy-MM-dd'T'HH:mm:ss",
"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'",
"yyyy-MM-dd'T'HH:mm:ss.SSSZ",
"yyyy-MM-dd HH:mm:ss",
"MM/dd/yyyy HH:mm:ss",
"MM/dd/yyyy'T'HH:mm:ss.SSS'Z'",
"MM/dd/yyyy'T'HH:mm:ss.SSSZ",
"MM/dd/yyyy'T'HH:mm:ss.SSS",
"MM/dd/yyyy'T'HH:mm:ssZ",
"MM/dd/yyyy'T'HH:mm:ss",
"yyyy:MM:dd HH:mm:ss"
};
private List<DateFormat> dateParsers;
private int activeDateParser;
/**
* Creates a new instance.
*/
public FallbackDateParser() {
// Build a list of candidate date parsers.
dateParsers = new ArrayList<DateFormat>(formats.length);
for (int i = 0; i < formats.length; i++) {
dateParsers.add(new SimpleDateFormat(formats[i]));
}
// We haven't selected a date parser yet.
activeDateParser = -1;
}
/**
* Attempts to parse the specified date.
*
* @param date
* The date to parse.
* @return The date.
* @throws ParseException
* Occurs if the date does not match any of the supported date
* formats.
*/
public Date parse(String date) throws ParseException {
String correctedDate;
// Try to fix ruby's broken xmlschema - format
// Replace this:
// 2007-02-12T18:43:01+00:00
// With this:
// 2007-02-12T18:43:01+0000
if (date.length() == 25 && date.charAt(22) == ':') {
correctedDate = date.substring(0, 22) + date.substring(23, 25);
} else {
correctedDate = date;
}
// If we have previously successfully used a date parser, we'll try it
// first.
if (activeDateParser >= 0) {
try {
return dateParsers.get(activeDateParser).parse(correctedDate);
} catch (ParseException e) {
// The currently active parser didn't work, so we must clear it
// and find a new appropriate parser.
activeDateParser = -1;
}
}
// Try the date parsers one by one until a suitable format is found.
for (int i = 0; i < dateParsers.size(); i++) {
try {
Date result;
// Attempt to parse with the current parser, if successful we
// store its index for next time.
result = dateParsers.get(i).parse(correctedDate);
activeDateParser = i;
return result;
} catch (ParseException pe) {
// Ignore parsing errors and try the next pattern.
}
}
throw new ParseException("The date string (" + date + ") could not be parsed.", 0);
}
}