/*
* @(#)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
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
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* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed or intended for use in
* the design, construction, operation or maintenance of any nuclear facility.
*/
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;
import com.sun.xacml.Constants;
import com.sun.xacml.ParsingException;
/**
* 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 = TypeIdentifierConstants.DATE;
/**
* URI version of name for this type
* <p>
* 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.
* <p>
* 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 = URI.create(identifier);
} catch (IllegalArgumentException e) {
earlyException = e;
}
}
/**
* 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.
*/
private 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 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 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.
// Multiplication with 1L to avoid overflows in the
// integer multiplication, since it's converted to long anyway
millis += 1L * currOffset * MILLIS_PER_MINUTE;
// Reset to last GMT midnight
millis -= millis % MILLIS_PER_DAY;
// Skip forward by time zone offset.
// Multiplication with 1L to avoid overflows in the
// integer multiplication, since it's converted to long anyway
millis -= 1L * 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) {
// Shouldn't happen, but just in case...
if (earlyException != null) {
throw earlyException;
}
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)
*
* @throws ParseException
* @throws ParsingException
*/
public static DateAttribute getInstance(Node root)
throws ParseException, ParsingException {
if (root.getFirstChild() != null) {
return getInstance(root.getFirstChild().getNodeValue());
}
throw new ParsingException("Error while parsing"
+ "a DateAttribute");
}
/**
* 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)
*
* @throws ParseException
* @throws ParsingException
*/
public static DateAttribute getInstance(String value)
throws ParseException, ParsingException {
if (value == null) {
throw new ParsingException("Can't create a "
+ "DateAttribute from null input");
}
Date dateValue = null;
int timeZone;
int defaultedTimeZone;
// This simple parser has no time zone
DateFormat simpleParser = new SimpleDateFormat("yyyy-MM-dd");
simpleParser.setLenient(false);
// This parser has a four digit offset to GMT with sign
DateFormat zoneParser = new SimpleDateFormat("yyyy-MM-ddZ");
// FIXME: temporarily we need to set this to true
// this is a problem with Java 1.5, if you now
// of good documentation about the differnces between
// SimpleDateFormat in 1.4 and 1.5 let me (ludwig) know.
zoneParser.setLenient(true);
// 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 void initParsers() {
// If simpleParser is already set, we're done.
if (this.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
this.simpleParser = new SimpleDateFormat("yyyy-MM-dd");
this.simpleParser.setLenient(false);
// This parser has a four digit offset to GMT with sign
this.zoneParser = new SimpleDateFormat("yyyy-MM-ddZ");
// FIXME: temporarily we need to set this to true
// this is a problem with Java 1.5, if you now
// of good documentation about the differnces between
// SimpleDateFormat in 1.4 and 1.5 let me (ludwig) know.
this.zoneParser.setLenient(true);
}
}
/**
* 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) this.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 this.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 this.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 this.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 this.value.hashCode();
}
/**
* Converts to a String representation.
*
* @return the String representation
*/
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append("DateAttribute: [" + Constants.nl);
sb.append(" Date: " + this.value + " local time");
sb.append(" TimeZone: " + this.timeZone);
sb.append(" Defaulted TimeZone: " + this.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 (this.encodedValue != null) {
return this.encodedValue;
}
if (this.timeZone == TZ_UNSPECIFIED) {
// If no time zone was specified, format Date value in
// local time with no time zone string.
initParsers();
synchronized (this.simpleParser) {
this.encodedValue = this.simpleParser.format(this.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.
this.encodedValue = formatDateWithTZ();
}
return this.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 (this.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.
this.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);
// 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).
this.gmtCalendar.setTime(this.value);
// Bump by the timeZone (so we get the right date/time that
// that we want to format)
this.gmtCalendar.add(Calendar.MINUTE, this.timeZone);
// Now, assemble the string
int year = this.gmtCalendar.get(Calendar.YEAR);
buf.append(zeroPadInt(year, 4));
buf.append('-');
// JANUARY is 0
int month = this.gmtCalendar.get(Calendar.MONTH) + 1;
buf.append(zeroPadInt(month, 2));
buf.append('-');
int dom = this.gmtCalendar.get(Calendar.DAY_OF_MONTH);
buf.append(zeroPadInt(dom, 2));
int tzNoSign = this.timeZone;
if (this.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);
}
}