/*
* @(#)DateAttribute.java
*
* Copyright 2003-2004 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistribution of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistribution in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
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* You acknowledge that this software is not designed or intended for use in
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*/
package com.sun.xacml.attr;
import java.net.URI;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;
import org.w3c.dom.Node;
/**
* Representation of an xs:date value. This class supports parsing xs:date values. All objects of
* this class are immutable and thread-safe. The <code>Date</code> 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 DateAttribute extends AttributeValue {
/**
* Official name of this type
*/
public static final String identifier = "http://www.w3.org/2001/XMLSchema#date";
/**
* URI version of name for this type
* <p>
* This object is used for synchronization whenever we need protection across this whole class.
*/
private static final URI identifierURI = URI.create(identifier);
/**
* Parser for dates with no time zones
* <p>
* This field is only initialized if needed (by initParsers()).
* <p>
* 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)
* <p>
* This field is only initialized if needed (by initParsers()).
* <p>
* NOTE: This object should only be accessed from code that has a lock on it, since
* SimpleDateFormat objects are not thread-safe.
*/
private static DateFormat zoneParser;
/**
* Calendar for GMT
* <p>
* 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;
/**
* Number of nanoseconds per millisecond (shared by other classes in this package)
*/
static final int NANOS_PER_MILLI = 1000000;
/**
* Number of milliseconds per second (shared by other classes in this package)
*/
static final int MILLIS_PER_SECOND = 1000;
/**
* Number of seconds in a minute (shared by other classes in this package)
*/
static final int SECONDS_PER_MINUTE = 60;
/**
* Number of minutes in an hour (shared by other classes in this package)
*/
static final int MINUTES_PER_HOUR = 60;
/**
* Number of hours in a day (shared by other classes in this package)
*/
static final int HOURS_PER_DAY = 24;
/**
* Number of nanoseconds per second (shared by other classes in this package)
*/
static final int NANOS_PER_SECOND = NANOS_PER_MILLI * MILLIS_PER_SECOND;
/**
* Number of milliseconds in a minute (shared by other classes in this package)
*/
static final int MILLIS_PER_MINUTE = MILLIS_PER_SECOND * SECONDS_PER_MINUTE;
/**
* Number of milliseconds in an hour (shared by other classes in this package)
*/
static final int MILLIS_PER_HOUR = MILLIS_PER_MINUTE * MINUTES_PER_HOUR;
/**
* Number of milliseconds in a day (shared by other classes in this package)
*/
static final long MILLIS_PER_DAY = MILLIS_PER_HOUR * HOURS_PER_DAY;
/**
* Time zone value that indicates that the time zone was not specified.
*/
public static final int TZ_UNSPECIFIED = -1000000;
/**
* The instant (in GMT) at which the specified date began (midnight) in the specified time zone.
* If no time zone was specified, the local time zone is used.
*/
private Date value;
/**
* 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 <code>TimeAttribute</code> that represents the current date in the default time
* zone.
*/
public DateAttribute() {
this(new Date());
}
/**
* Creates a new <code>TimeAttribute</code> that represents the given date with default timezone
* values.
*
* @param date
* a <code>Date</code> object representing the instant at which the specified date
* began (midnight) in the specified time zone (the actual time value will be forced
* to midnight)
*/
public DateAttribute(Date date) {
super(identifierURI);
// Get the current time and GMT offset
int currOffset = DateTimeAttribute.getDefaultTZOffset(date);
long millis = date.getTime();
// Now find out the last time it was midnight local time
// (actually the last time it was midnight with the current
// GMT offset, but that's good enough).
// Skip back by time zone offset.
millis += currOffset * MILLIS_PER_MINUTE;
// Reset to last GMT midnight
millis -= millis % MILLIS_PER_DAY;
// Skip forward by time zone offset.
millis -= currOffset * MILLIS_PER_MINUTE;
date.setTime(millis);
init(date, currOffset, currOffset);
}
/**
* Creates a new <code>DateAttribute</code> that represents the date supplied.
*
* @param date
* a <code>Date</code> object representing the instant at which the specified date
* began (midnight) in the specified time zone
* @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 DateAttribute(Date date, int timeZone, int defaultedTimeZone) {
super(identifierURI);
init(date, timeZone, defaultedTimeZone);
}
/**
* Initialization code shared by constructors.
*
* @param date
* a <code>Date</code> object representing the instant at which the specified date
* began (midnight) in the specified time zone.
* @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 timeZone, int defaultedTimeZone) {
this.value = (Date) date.clone();
this.timeZone = timeZone;
this.defaultedTimeZone = defaultedTimeZone;
}
/**
* Returns a new <code>DateAttribute</code> that represents the xs:date at a particular DOM
* node.
*
* @param root
* the <code>Node</code> that contains the desired value
* @return a new <code>DateAttribute</code> representing the appropriate value (null if there is
* a parsing error)
*/
public static DateAttribute getInstance(Node root) throws ParseException {
return getInstance(root.getFirstChild().getNodeValue());
}
/**
* Returns a new <code>DateAttribute</code> that represents the xs:date value indicated by the
* string provided.
*
* @param value
* a string representing the desired value
* @return a new <code>DateAttribute</code> representing the desired value (null if there is a
* parsing error)
*/
public static DateAttribute getInstance(String value) throws ParseException {
Date dateValue = null;
int timeZone;
int defaultedTimeZone;
if (simpleParser == null)
initParsers();
// If string ends with Z, it's in GMT. Chop off the Z and
// add +0000 to make the time zone explicit, then parse it
// with the timezone parser.
if (value.endsWith("Z")) {
value = value.substring(0, value.length() - 1) + "+0000";
dateValue = strictParse(zoneParser, value);
timeZone = 0;
defaultedTimeZone = 0;
} else {
// If string ends with :XX, it must have a time zone
// or be invalid. Strip off the possible time zone and
// make sure what's left is a valid simple date. If so,
// reformat the time zone by stripping out the colon
// and parse the whole thing with the timezone parser.
int len = value.length();
if ((len > 6) && (value.charAt(len - 3) == ':')) {
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.
dateValue = strictParse(simpleParser, value);
timeZone = TZ_UNSPECIFIED;
Date gmtValue = strictParse(zoneParser, value + "+0000");
defaultedTimeZone = (int) (gmtValue.getTime() - dateValue.getTime());
defaultedTimeZone = defaultedTimeZone / 60000;
}
}
// If parsing went OK, create a new DateAttribute object and
// return it.
DateAttribute attr = new DateAttribute(dateValue, 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.
* <p>
* 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;
// 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");
simpleParser.setLenient(false);
// This parser has a four digit offset to GMT with sign
zoneParser = new SimpleDateFormat("yyyy-MM-ddZ");
zoneParser.setLenient(false);
}
}
/**
* Gets the date represented by this object. The return value is a <code>Date</code> object
* representing the instant at which the specified date began (midnight) in the time zone.
* <p>
* <b>NOTE:</b> The <code>Date</code> object is cloned before it is returned to avoid
* unauthorized changes.
*
* @return a <code>Date</code> object representing the instant at which the date began
*/
public Date getValue() {
return (Date) value.clone();
}
/**
* Gets the specified 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.
* <p>
* Two <code>DateAttribute</code>s are equal if and only if the instant on which the date began
* is equal. This means that they must have the same time zone.
*
* @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 DateAttribute))
return false;
DateAttribute other = (DateAttribute) o;
return value.equals(other.value);
}
/**
* 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() {
// Only the value field is considered by the equals method, so only
// that field should be considered by this method.
return value.hashCode();
}
/**
* Converts to a String representation.
*
* @return the String representation
*/
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append("DateAttribute: [\n");
sb.append(" Date: " + value + " local time");
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 <code>String</code> 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);
}
} 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 = formatDateWithTZ();
}
return encodedValue;
}
/**
* Encodes the value of this object as an xsi:date. Only for use when the time zone is
* specified.
*
* @return a <code>String</code> form of the value
*/
private String formatDateWithTZ() {
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-DD+hh:mm".length() = 16
// Length may be longer if years < -999 or > 9999
StringBuffer buf = new StringBuffer(16);
synchronized (gmtCalendar) {
// Start with the GMT instant when the date started in the
// specified time zone (would be 7:00 PM the preceding day
// if the specified time zone was +0500).
gmtCalendar.setTime(value);
// Bump by the timeZone (so we get the right date/time that
// that we want to format)
gmtCalendar.add(Calendar.MINUTE, timeZone);
// Now, assemble the string
int year = gmtCalendar.get(Calendar.YEAR);
buf.append(zeroPadInt(year, 4));
buf.append('-');
// JANUARY is 0
int month = gmtCalendar.get(Calendar.MONTH) + 1;
buf.append(zeroPadInt(month, 2));
buf.append('-');
int dom = gmtCalendar.get(Calendar.DAY_OF_MONTH);
buf.append(zeroPadInt(dom, 2));
}
int tzNoSign = timeZone;
if (timeZone < 0) {
tzNoSign = -tzNoSign;
buf.append('-');
} else
buf.append('+');
int tzHours = tzNoSign / 60;
buf.append(zeroPadInt(tzHours, 2));
buf.append(':');
int tzMinutes = tzNoSign % 60;
buf.append(zeroPadInt(tzMinutes, 2));
return buf.toString();
}
/**
* Takes a String representation of an integer (an optional sign followed by digits) and pads it
* with zeros on the left until it has at least the specified number of digits. Note that this
* function will work for an integer of any size: int, long, etc.
*
* @param unpadded
* the unpadded <code>String</code> (must have length of at least one)
* @param minDigits
* the minimum number of digits desired
* @return the padded <code>String</code>
*/
static String zeroPadIntString(String unpadded, int minDigits) {
int len = unpadded.length();
// Get the sign character (or 0 if none)
char sign = unpadded.charAt(0);
if ((sign != '-') && (sign != '+'))
sign = 0;
// The number of characters required is the number of digits,
// plus one for the sign if present.
int minChars = minDigits;
if (sign != 0)
minChars++;
// If we already have that many characters, we're done.
if (len >= minChars)
return unpadded;
// Otherwise, create the buffer
StringBuffer buf = new StringBuffer();
// Copy in the sign first, if present
if (sign != 0) {
buf.append(sign);
}
// Add the zeros
int zerosNeeded = minChars - len;
while (zerosNeeded-- != 0)
buf.append('0');
// Copy the rest of the unpadded string
if (sign != 0) {
// Skip sign
buf.append(unpadded.substring(1, len));
} else {
buf.append(unpadded);
}
return buf.toString();
}
/**
* Converts an integer to a base 10 string and pads it with zeros on the left until it has at
* least the specified number of digits. Note that the length of the resulting string will be
* greater than minDigits if the number is negative since the string will start with a minus
* sign.
*
* @param intValue
* the integer to convert
* @param minDigits
* the minimum number of digits desired
* @return the padded <code>String</code>
*/
static String zeroPadInt(int intValue, int minDigits) {
return zeroPadIntString(Integer.toString(intValue), minDigits);
}
}