Date objects returned are not, but
* these objects are cloned before being returned.
*
* @since 1.0
* @author Marco Barreno
* @author Seth Proctor
* @author Steve Hanna
*/
public class DateTimeAttribute extends AttributeValue
{
/**
* Official name of this type
*/
public static final String identifier =
"http://www.w3.org/2001/XMLSchema#dateTime";
/**
* URI version of name for this type
* * This field is initialized by a static initializer so that * we can catch any exceptions thrown by URI(String) and * transform them into a RuntimeException, since this should * never happen but should be reported properly if it ever does. *
* This object is used for synchronization whenever we need * protection across this whole class. */ private static URI identifierURI; /** * RuntimeException that wraps an Exception thrown during the * creation of identifierURI, null if none. */ private static RuntimeException earlyException; /** * Static initializer that initializes the identifierURI * class field so that we can catch any exceptions thrown * by URI(String) and transform them into a RuntimeException. * Such exceptions should never happen but should be reported * properly if they ever do. */ static { try { identifierURI = new URI(identifier); } catch (Exception e) { earlyException = new IllegalArgumentException(); earlyException.initCause(e); } }; /** * Parser for dates with no time zones *
* This field is only initialized if needed (by initParsers()). *
* NOTE: This object should only be accessed from code that * has synchronized on it, since SimpleDateFormat objects are not * thread-safe. If this is causing performance problems, we could * easily make this a method variable in methods that use it * instead of a class field. But that would mean we'd need to * spend a lot more time creating these objects. */ private static DateFormat simpleParser; /** * Parser for dates with RFC 822 time zones (like +0300) *
* This field is only initialized if needed (by initParsers()). *
* NOTE: This object should only be accessed from code that * has synchronized on it, since SimpleDateFormat objects are not * thread-safe. */ private static DateFormat zoneParser; /** * Calendar for GMT *
* NOTE: This object should only be accessed from code that * has a lock on it, since Calendar objects are not generally * thread-safe. */ private static Calendar gmtCalendar; /** * Time zone value that indicates that the time zone was not * specified. */ public static final int TZ_UNSPECIFIED = -1000000; /** * The actual date and time that this object represents (in GMT, * as with all Date objects). If no time zone was specified, the * local time zone is used to convert to GMT. *
* This Date does not include fractions of a second. Those are
* handled by the separate nanoseconds field, since Date only
* provides millisecond accuracy and the XML Query spec requires
* at least 100 nanosecond accuracy.
*/
private Date value;
/**
* The number of nanoseconds beyond the Date given by the value
* field. The XML Query document says that fractional seconds
* must be supported down to at least 100 nanosecond resolution.
* The Date class only supports milliseconds, so we include here
* support for nanosecond resolution.
*/
private int nanoseconds;
/**
* The time zone specified for this object (or TZ_UNSPECIFIED if
* unspecified). The offset to GMT, in minutes.
*/
private int timeZone;
/**
* The time zone actually used for this object (if it was
* originally unspecified, the default time zone used).
* The offset to GMT, in minutes.
*/
private int defaultedTimeZone;
/**
* Cached encoded value (null if not cached yet).
*/
private String encodedValue = null;
/**
* Creates a new DateTimeAttribute that represents
* the current date in the default time zone.
*/
public DateTimeAttribute() {
super(identifierURI);
Date currDate = new Date();
int currOffset = getDefaultTZOffset(currDate);
init(currDate, 0, currOffset, currOffset);
}
/**
* Creates a new DateTimeAttribute that represents
* the date supplied.
*
* @param date a Date object representing the
* specified date and time down to second
* resolution. If this object has non-zero
* milliseconds, they are combined
* with the nanoseconds parameter.
* @param nanoseconds the number of nanoseconds beyond the
* Date specified in the date parameter
* @param timeZone the time zone specified for this object
* (or TZ_UNSPECIFIED if unspecified). The
* offset to GMT, in minutes.
* @param defaultedTimeZone the time zone actually used for this
* object (if it was originally unspecified,
* the default time zone used).
* The offset to GMT, in minutes.
*/
public DateTimeAttribute(Date date, int nanoseconds, int timeZone,
int defaultedTimeZone) {
super(identifierURI);
init(date, nanoseconds, timeZone, defaultedTimeZone);
}
/**
* Initialization code shared by constructors.
*
* @param date a Date object representing the
* specified date and time down to second
* resolution. If this object has non-zero
* milliseconds, they are combined
* with the nanoseconds parameter.
* @param nanoseconds the number of nanoseconds beyond the
* Date specified in the date parameter
* @param timeZone the time zone specified for this object
* (or TZ_UNSPECIFIED if unspecified). The
* offset to GMT, in minutes.
* @param defaultedTimeZone the time zone actually used for this
* object (if it was originally unspecified,
* the default time zone used).
* The offset to GMT, in minutes.
*/
private void init(Date date, int nanoseconds, int timeZone,
int defaultedTimeZone) {
// Shouldn't happen, but just in case...
if (earlyException != null)
throw earlyException;
// Make a new Date object
this.value = (Date) date.clone();
// Combine the nanoseconds so they are between 0 and 999,999,999
this.nanoseconds = combineNanos(this.value, nanoseconds);
this.timeZone = timeZone;
this.defaultedTimeZone = defaultedTimeZone;
}
/**
* Returns a new DateTimeAttribute that represents
* the xs:dateTime at a particular DOM node.
*
* @param root the Node that contains the desired value
* @return a new DateTimeAttribute representing the
* appropriate value
* @throws ParsingException if any problems occurred while parsing
*/
public static DateTimeAttribute getInstance(Node root)
throws ParsingException, NumberFormatException, ParseException
{
return getInstance(root.getFirstChild().getNodeValue());
}
/**
* Returns a new DateTimeAttribute that represents
* the xs:dateTime value indicated by the string provided.
*
* @param value a string representing the desired value
* @return a new DateTimeAttribute representing the
* desired value
* @throws ParsingException if the text is formatted incorrectly
* @throws NumberFormatException if the nanosecond format is incorrect
* @throws ParseException
*/
public static DateTimeAttribute getInstance(String value)
throws ParsingException, NumberFormatException, ParseException
{
Date dateValue = null;
int nanoseconds = 0;
int timeZone;
int defaultedTimeZone;
initParsers();
// If string ends with Z, it's in GMT. Chop off the Z and
// add +00:00 to make the time zone explicit.
if (value.endsWith("Z"))
value = value.substring(0, value.length()-1) + "+00:00";
// Figure out if the string has a time zone.
// If string ends with +XX:XX or -XX:XX, it must have
// a time zone or be invalid.
int len = value.length(); // This variable is often not up-to-date
boolean hasTimeZone = ((value.charAt(len-3) == ':') &&
((value.charAt(len-6) == '-') ||
(value.charAt(len-6) == '+')));
// If string contains a period, it must have fractional
// seconds (or be invalid). Strip them out and put the
// value in nanoseconds.
int dotIndex = value.indexOf('.');
if (dotIndex != -1) {
// Decide where fractional seconds end.
int secondsEnd = value.length();
if (hasTimeZone)
secondsEnd -= 6;
// Copy the fractional seconds out of the string.
String nanoString = value.substring(dotIndex+1, secondsEnd);
// Check that all those characters are ASCII digits.
for (int i = nanoString.length()-1; i >= 0; i--) {
char c = nanoString.charAt(i);
if ((c < '0') || (c > '9'))
throw new ParsingException("non-ascii digit found");
}
// If there are less than 9 digits in the fractional seconds,
// pad with zeros on the right so it's nanoseconds.
while (nanoString.length() < 9)
nanoString += "0";
// If there are more than 9 digits in the fractional seconds,
// drop the least significant digits.
if (nanoString.length() > 9) {
nanoString = nanoString.substring(0, 9);
}
// Parse the fractional seconds.
nanoseconds = Integer.parseInt(nanoString);
// Remove the fractional seconds from the string.
value = value.substring(0, dotIndex) +
value.substring(secondsEnd, value.length());
}
// this is the code that may trow a ParseException
if (hasTimeZone) {
// Strip off the purported time zone and make sure what's
// left is a valid unzoned date and time (by parsing in GMT).
// If so, reformat the time zone by stripping out the colon
// and parse the revised string with the timezone parser.
len = value.length();
Date gmtValue = strictParse(zoneParser,
value.substring(0,len-6) + "+0000");
value = value.substring(0, len-3) +
value.substring(len-2, len);
dateValue = strictParse(zoneParser, value);
timeZone =
(int) (gmtValue.getTime() - dateValue.getTime());
timeZone = timeZone / 60000;
defaultedTimeZone = timeZone;
} else {
// No funny business. This must be a simple date and time.
dateValue = strictParse(simpleParser, value);
timeZone = TZ_UNSPECIFIED;
// Figure out what time zone was used.
Date gmtValue = strictParse(zoneParser, value + "+0000");
defaultedTimeZone =
(int) (gmtValue.getTime() - dateValue.getTime());
defaultedTimeZone = defaultedTimeZone / 60000;
}
// If parsing went OK, create a new DateTimeAttribute object and
// return it.
DateTimeAttribute attr = new DateTimeAttribute(dateValue, nanoseconds,
timeZone,
defaultedTimeZone);
return attr;
}
/**
* Parse a String using a DateFormat parser, requiring that
* the entire String be consumed by the parser. On success,
* return a Date. On failure, throw a ParseException.
*
* Synchronize on the parser object when using it, since we
* assume they're the shared static objects in this class.
*/
private static Date strictParse(DateFormat parser, String str)
throws ParseException {
ParsePosition pos = new ParsePosition(0);
Date ret;
synchronized (parser) {
ret = parser.parse(str, pos);
}
if (pos.getIndex() != str.length())
throw new ParseException("", 0);
return ret;
}
/**
* Initialize the parser objects.
*/
private static void initParsers() {
// If simpleParser is already set, we're done.
if (simpleParser != null)
return;
// Make sure that identifierURI is not null
if (earlyException != null)
throw earlyException;
// Synchronize on identifierURI while initializing parsers
// so we don't end up using a half-way initialized parser
synchronized (identifierURI) {
// This simple parser has no time zone
simpleParser = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
simpleParser.setLenient(false);
// This parser has a four digit offset to GMT with sign
zoneParser = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ");
zoneParser.setLenient(false);
}
}
/**
* Gets the date and time represented by this object. The return
* value is a Date object representing the
* specified date and time down to second resolution.
* Subsecond values are handled by the
* {@link #getNanoseconds getNanoseconds} method.
*
* NOTE: The Date object is cloned before it
* is returned to avoid unauthorized changes.
*
* @return a Date object representing the date and
* time represented by this object
*/
public Date getValue() {
return (Date) value.clone();
}
/**
* Gets the nanoseconds of this object.
*
* @return the number of nanoseconds
*/
public int getNanoseconds() {
return nanoseconds;
}
/**
* Gets the time zone of this object (or TZ_UNSPECIFIED if
* unspecified).
*
* @return the offset to GMT in minutes (positive or negative)
*/
public int getTimeZone() {
return timeZone;
}
/**
* Gets the time zone actually used for this object (if it was
* originally unspecified, the default time zone used).
*
* @return the offset to GMT in minutes (positive or negative)
*/
public int getDefaultedTimeZone() {
return defaultedTimeZone;
}
/**
* Returns true if the input is an instance of this class and if its
* value equals the value contained in this class.
*
* Two DateTimeAttributes are equal if and only if the
* dates and times represented are identical (down to the nanosecond).
*
* @param o the object to compare
*
* @return true if this object and the input represent the same value
*/
public boolean equals(Object o) {
if (! (o instanceof DateTimeAttribute))
return false;
DateTimeAttribute other = (DateTimeAttribute)o;
// Since the value field is normalized into GMT, this is a
// good way to compare.
return (value.equals(other.value) &&
(nanoseconds == other.nanoseconds));
}
/**
* Returns the hashcode value used to index and compare this object with
* others of the same type.
*
* @return the object's hashcode value
*/
public int hashCode() {
// Both the value field and the nanoseconds field are considered
// by the equals method, so it's best if the hashCode is derived
// from both of those fields.
int hashCode = value.hashCode();
hashCode = 31*hashCode + nanoseconds;
return hashCode;
}
/**
* Converts to a String representation.
*
* @return the String representation
*/
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append("DateTimeAttribute: [\n");
sb.append(" Date: " + value + " local time");
sb.append(" Nanoseconds: " + nanoseconds);
sb.append(" TimeZone: " + timeZone);
sb.append(" Defaulted TimeZone: " + defaultedTimeZone);
sb.append("]");
return sb.toString();
}
/**
* Encodes the value in a form suitable for including in XML data like
* a request or an obligation. This must return a value that could in
* turn be used by the factory to create a new instance with the same
* value.
*
* @return a String form of the value
*/
public String encode() {
if (encodedValue != null)
return encodedValue;
if (timeZone == TZ_UNSPECIFIED) {
// If no time zone was specified, format Date value in
// local time with no time zone string.
initParsers();
synchronized (simpleParser) {
encodedValue = simpleParser.format(value);
}
if (nanoseconds != 0) {
encodedValue = encodedValue + "." +
DateAttribute.zeroPadInt(nanoseconds, 9);
}
} else {
// If a time zone was specified, don't use SimpleParser
// because it can only format dates in the local (default)
// time zone. And the offset between that time zone and the
// time zone we need to display can vary in complicated ways.
// Instead, do it ourselves using our formatDateWithTZ method.
encodedValue = formatDateTimeWithTZ();
}
return encodedValue;
}
/**
* Encodes the value of this object as an xsi:dateTime.
* Only for use when the time zone is specified.
*
* @return a String form of the value
*/
private String formatDateTimeWithTZ() {
if (gmtCalendar == null) {
TimeZone gmtTimeZone = TimeZone.getTimeZone("GMT");
// Locale doesn't make much difference here. We don't use
// any of the strings in the Locale and we don't do anything
// that depends on week count conventions. We use the US
// locale because it's always around and it ensures that we
// will always get a Gregorian calendar, which is necessary
// for compliance with ISO 8501.
gmtCalendar = Calendar.getInstance(gmtTimeZone, Locale.US);
}
// "YYYY-MM-DDThh:mm:ss.sssssssss+hh:mm".length() = 35
// Length may be longer if years < -999 or > 9999
StringBuffer buf = new StringBuffer(35);
synchronized (gmtCalendar) {
// Start with the proper time in GMT.
gmtCalendar.setTime(value);
// Bump by the timeZone, since we're going to be extracting
// the value in GMT
gmtCalendar.add(Calendar.MINUTE, timeZone);
// Now, assemble the string
int year = gmtCalendar.get(Calendar.YEAR);
buf.append(DateAttribute.zeroPadInt(year, 4));
buf.append('-');
// JANUARY is 0
int month = gmtCalendar.get(Calendar.MONTH) + 1;
buf.append(DateAttribute.zeroPadInt(month, 2));
buf.append('-');
int dom = gmtCalendar.get(Calendar.DAY_OF_MONTH);
buf.append(DateAttribute.zeroPadInt(dom, 2));
buf.append('T');
int hour = gmtCalendar.get(Calendar.HOUR_OF_DAY);
buf.append(DateAttribute.zeroPadInt(hour, 2));
buf.append(':');
int minute = gmtCalendar.get(Calendar.MINUTE);
buf.append(DateAttribute.zeroPadInt(minute, 2));
buf.append(':');
int second = gmtCalendar.get(Calendar.SECOND);
buf.append(DateAttribute.zeroPadInt(second, 2));
}
if (nanoseconds != 0) {
buf.append('.');
buf.append(DateAttribute.zeroPadInt(nanoseconds, 9));
}
int tzNoSign = timeZone;
if (timeZone < 0) {
tzNoSign = -tzNoSign;
buf.append('-');
} else
buf.append('+');
int tzHours = tzNoSign / 60;
buf.append(DateAttribute.zeroPadInt(tzHours, 2));
buf.append(':');
int tzMinutes = tzNoSign % 60;
buf.append(DateAttribute.zeroPadInt(tzMinutes, 2));
return buf.toString();
}
/**
* Gets the offset in minutes between the default time zone and
* UTC for the specified date.
*
* @param the Date whose offset is desired
* @return the offset in minutes
*/
static int getDefaultTZOffset(Date date) {
int offset = TimeZone.getDefault().getOffset(date.getTime());
offset = offset / DateAttribute.MILLIS_PER_MINUTE;
return offset;
}
/**
* Combines a number of nanoseconds with a Date
* so that the Date has no fractional seconds and the number
* of nanoseconds is non-negative and less than a second.
*
* WARNING: This function changes the value stored in
* the date parameter!
*
* @param date the Date to be combined
* (value may be modified!)
* @param nanos the nanoseconds to be combined
* @return the resulting number of nanoseconds
*/
static int combineNanos(Date date, int nanoseconds) {
long millis = date.getTime();
int milliCarry = (int) (millis % DateAttribute.MILLIS_PER_SECOND);
// If nothing needs fixing, get out quick
if ((milliCarry == 0) && (nanoseconds > 0)
&& (nanoseconds < DateAttribute.NANOS_PER_SECOND))
return nanoseconds;
// Remove any non-zero milliseconds from the date.
millis -= milliCarry;
// Add them into the nanoseconds.
long nanoTemp = nanoseconds;
nanoTemp += milliCarry * DateAttribute.NANOS_PER_MILLI;
// Get the nanoseconds that represent fractional seconds.
// This we'll return.
int nanoResult = (int) (nanoTemp % DateAttribute.NANOS_PER_SECOND);
// Get nanoseconds that represent whole seconds.
nanoTemp -= nanoResult;
// Convert that to milliseconds and add it back to the date.
millis += nanoTemp / DateAttribute.NANOS_PER_MILLI;
date.setTime(millis);
return nanoResult;
}
}