dateattribute.java

sunxacml源码

/*
 * @(#)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
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
 * 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.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
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 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 = new URI(identifier);
        } catch (Exception e) {
            earlyException = new IllegalArgumentException();
            earlyException.initCause(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. 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) {

        // 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)
     */
    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;