datetimeattribute.java

sunxacml源码

/*
 * @(#)DateTimeAttribute.java
 *
 * Copyright 2003-2006 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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 *
 * 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 com.sun.xacml.ParsingException;

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:dateTime value. This class supports parsing
 * xs:dateTime 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 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
     * <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 synchronized 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;

    /**
     * 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.
     * <p>
     * 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 <code>DateTimeAttribute</code> that represents
     * the current date in the default time zone.
     */
    public DateTimeAttribute() {
        this(new Date());
    }

    /**
     * Creates a new <code>DateTimeAttribute</code> that represents
     * the supplied date but uses default timezone and offset values.
     *
     * @param dateTime a <code>Date</code> 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.
     */
    public DateTimeAttribute(Date dateTime) {
        super(identifierURI);

        int currOffset = getDefaultTZOffset(dateTime);
        init(dateTime, 0, currOffset, currOffset);
    }

    /**
     * Creates a new <code>DateTimeAttribute</code> that represents
     * the date supplied.
     *
     * @param dateTime a <code>Date</code> 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 dateTime, int nanoseconds, int timeZone,
                             int defaultedTimeZone) {
        super(identifierURI);

        init(dateTime, nanoseconds, timeZone, defaultedTimeZone);
    }

    /**
     * Initialization code shared by constructors.
     *
     * @param date a <code>Date</code> 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 <code>DateTimeAttribute</code> that represents
     * the xs:dateTime at a particular DOM node.
     *
     * @param root the <code>Node</code> that contains the desired value
     * @return a new <code>DateTimeAttribute</code> 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 <code>DateTimeAttribute</code> that represents
     * the xs:dateTime value indicated by the string provided.
     *
     * @param value a string representing the desired value
     * @return a new <code>DateTimeAttribute</code> 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.