exsltdatetime.java

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/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: ExsltDatetime.java,v 1.2.4.1 2005/09/10 18:50:49 jeffsuttor Exp $
 */

package com.sun.org.apache.xalan.internal.lib;


import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;

import com.sun.org.apache.xpath.internal.objects.XBoolean;
import com.sun.org.apache.xpath.internal.objects.XNumber;
import com.sun.org.apache.xpath.internal.objects.XObject;

/**
 * This class contains EXSLT dates and times extension functions.
 * It is accessed by specifying a namespace URI as follows:
 * <pre>
 *    xmlns:datetime="http://exslt.org/dates-and-times"
 * </pre>
 * 
 * The documentation for each function has been copied from the relevant
 * EXSLT Implementer page.
 * 
 * @see <a href="http://www.exslt.org/">EXSLT</a>
 * @xsl.usage general
 */

public class ExsltDatetime
{
    // Datetime formats (era and zone handled separately).
    static final String dt = "yyyy-MM-dd'T'HH:mm:ss";
    static final String d = "yyyy-MM-dd";
    static final String gym = "yyyy-MM";
    static final String gy = "yyyy";
    static final String gmd = "--MM-dd";
    static final String gm = "--MM--";
    static final String gd = "---dd";
    static final String t = "HH:mm:ss";
    static final String EMPTY_STR = "";

    /**
     * The date:date-time function returns the current date and time as a date/time string. 
     * The date/time string that's returned must be a string in the format defined as the 
     * lexical representation of xs:dateTime in 
     * <a href="http://www.w3.org/TR/xmlschema-2/#dateTime">[3.2.7 dateTime]</a> of
     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.
     * The date/time format is basically CCYY-MM-DDThh:mm:ss, although implementers should consult
     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a> and 
     * <a href="http://www.iso.ch/markete/8601.pdf">[ISO 8601]</a> for details.
     * The date/time string format must include a time zone, either a Z to indicate Coordinated 
     * Universal Time or a + or - followed by the difference between the difference from UTC 
     * represented as hh:mm. 
     */
    public static String dateTime()
    {
      Calendar cal = Calendar.getInstance();
      Date datetime = cal.getTime();
      // Format for date and time.
      SimpleDateFormat dateFormat = new SimpleDateFormat(dt);
      
      StringBuffer buff = new StringBuffer(dateFormat.format(datetime));
      // Must also include offset from UTF.
      // Get the offset (in milliseconds).
      int offset = cal.get(Calendar.ZONE_OFFSET) + cal.get(Calendar.DST_OFFSET);
      // If there is no offset, we have "Coordinated
      // Universal Time."
      if (offset == 0)
        buff.append("Z");
      else
      {
        // Convert milliseconds to hours and minutes
        int hrs = offset/(60*60*1000);
        // In a few cases, the time zone may be +/-hh:30.
        int min = offset%(60*60*1000);
        char posneg = hrs < 0? '-': '+';
        buff.append(posneg + formatDigits(hrs) + ':' + formatDigits(min));
      }
      return buff.toString();
    }
    
    /**
     * Represent the hours and minutes with two-digit strings.
     * @param q hrs or minutes.
     * @return two-digit String representation of hrs or minutes.
     */
    private static String formatDigits(int q)
    {
      String dd = String.valueOf(Math.abs(q));
      return dd.length() == 1 ? '0' + dd : dd;
    }

    /**
     * The date:date function returns the date specified in the date/time string given 
     * as the argument. If no argument is given, then the current local date/time, as 
     * returned by date:date-time is used as a default argument. 
     * The date/time string that's returned must be a string in the format defined as the 
     * lexical representation of xs:dateTime in 
     * <a href="http://www.w3.org/TR/xmlschema-2/#dateTime">[3.2.7 dateTime]</a> of
     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.
     * If the argument is not in either of these formats, date:date returns an empty string (''). 
     * The date/time format is basically CCYY-MM-DDThh:mm:ss, although implementers should consult 
     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a> and 
     * <a href="http://www.iso.ch/markete/8601.pdf">[ISO 8601]</a> for details. 
     * The date is returned as a string with a lexical representation as defined for xs:date in 
     * [3.2.9 date] of [XML Schema Part 2: Datatypes]. The date format is basically CCYY-MM-DD, 
     * although implementers should consult [XML Schema Part 2: Datatypes] and [ISO 8601] for details.
     * If no argument is given or the argument date/time specifies a time zone, then the date string 
     * format must include a time zone, either a Z to indicate Coordinated Universal Time or a + or - 
     * followed by the difference between the difference from UTC represented as hh:mm. If an argument 
     * is specified and it does not specify a time zone, then the date string format must not include 
     * a time zone. 
     */
    public static String date(String datetimeIn)
      throws ParseException
    {
      String[] edz = getEraDatetimeZone(datetimeIn);
      String leader = edz[0];
      String datetime = edz[1];
      String zone = edz[2];
      if (datetime == null || zone == null) 
        return EMPTY_STR;
                    
      String[] formatsIn = {dt, d};
      String formatOut = d;
      Date date = testFormats(datetime, formatsIn);
      if (date == null) return EMPTY_STR;
      
      SimpleDateFormat dateFormat = new SimpleDateFormat(formatOut);
      dateFormat.setLenient(false);
      String dateOut = dateFormat.format(date);      
      if (dateOut.length() == 0)
          return EMPTY_STR;
      else        
        return (leader + dateOut + zone);
    }
    
    
    /**
     * See above.
     */
    public static String date()
    {
      String datetime = dateTime().toString();
      String date = datetime.substring(0, datetime.indexOf("T"));
      String zone = datetime.substring(getZoneStart(datetime));
      return (date + zone);
    }
    
    /**
     * The date:time function returns the time specified in the date/time string given 
     * as the argument. If no argument is given, then the current local date/time, as 
     * returned by date:date-time is used as a default argument. 
     * The date/time string that's returned must be a string in the format defined as the 
     * lexical representation of xs:dateTime in 
     * <a href="http://www.w3.org/TR/xmlschema-2/#dateTime">[3.2.7 dateTime]</a> of
     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>. 
     * If the argument string is not in this format, date:time returns an empty string (''). 
     * The date/time format is basically CCYY-MM-DDThh:mm:ss, although implementers should consult 
     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a> and 
     * <a href="http://www.iso.ch/markete/8601.pdf">[ISO 8601]</a> for details.
     * The date is returned as a string with a lexical representation as defined for xs:time in 
     * <a href="http://www.w3.org/TR/xmlschema-2/#time">[3.2.8 time]</a> of [XML Schema Part 2: Datatypes].
     * The time format is basically hh:mm:ss, although implementers should consult [XML Schema Part 2: 
     * Datatypes] and [ISO 8601] for details. 
     * If no argument is given or the argument date/time specifies a time zone, then the time string 
     * format must include a time zone, either a Z to indicate Coordinated Universal Time or a + or - 
     * followed by the difference between the difference from UTC represented as hh:mm. If an argument 
     * is specified and it does not specify a time zone, then the time string format must not include 
     * a time zone. 
     */
    public static String time(String timeIn)
      throws ParseException      
    {
      String[] edz = getEraDatetimeZone(timeIn);
      String time = edz[1];
      String zone = edz[2];
      if (time == null || zone == null) 
        return EMPTY_STR;
                    
      String[] formatsIn = {dt, d, t};
      String formatOut =  t;
      Date date = testFormats(time, formatsIn);
      if (date == null) return EMPTY_STR;
      SimpleDateFormat dateFormat = new SimpleDateFormat(formatOut);
      String out = dateFormat.format(date);
      return (out + zone);
    }

    /**
     * See above.
     */
    public static String time()
    {
      String datetime = dateTime().toString();
      String time = datetime.substring(datetime.indexOf("T")+1);
      
	  // The datetime() function returns the zone on the datetime string.  If we
	  // append it, we get the zone substring duplicated.
	  // Fix for JIRA 2013

      // String zone = datetime.substring(getZoneStart(datetime));      
      // return (time + zone);
      return (time);
    } 
       
    /**
     * The date:year function returns the year of a date as a number. If no 
     * argument is given, then the current local date/time, as returned by 
     * date:date-time is used as a default argument.
     * The date/time string specified as the first argument must be a right-truncated 
     * string in the format defined as the lexical representation of xs:dateTime in one 
     * of the formats defined in 
     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.
     * The permitted formats are as follows: 
     *   xs:dateTime (CCYY-MM-DDThh:mm:ss) 
     *   xs:date (CCYY-MM-DD) 
     *   xs:gYearMonth (CCYY-MM) 
     *   xs:gYear (CCYY) 
     * If the date/time string is not in one of these formats, then NaN is returned. 
     */
    public static double year(String datetimeIn)
      throws ParseException
    {
      String[] edz = getEraDatetimeZone(datetimeIn);
      boolean ad = edz[0].length() == 0; // AD (Common Era -- empty leader)
      String datetime = edz[1];
      if (datetime == null) 
        return Double.NaN;
      
      String[] formats = {dt, d, gym, gy};
      double yr = getNumber(datetime, formats, Calendar.YEAR);
      if (ad || yr == Double.NaN)
        return yr;
      else
        return -yr;
    }
     
    /**
     * See above.
     */
    public static double year()
    {
      Calendar cal = Calendar.getInstance();
      return cal.get(Calendar.YEAR);
    }
    
    /**
     * The date:month-in-year function returns the month of a date as a number. If no argument 
     * is given, then the current local date/time, as returned by date:date-time is used 
     * as a default argument. 
     * The date/time string specified as the first argument is a left or right-truncated 
     * string in the format defined as the lexical representation of xs:dateTime in one of 
     * the formats defined in 
     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>.
     * The permitted formats are as follows: 
     *    xs:dateTime (CCYY-MM-DDThh:mm:ss) 
     *    xs:date (CCYY-MM-DD) 
     *    xs:gYearMonth (CCYY-MM)
     *    xs:gMonth (--MM--) 
     *    xs:gMonthDay (--MM-DD)
     * If the date/time string is not in one of these formats, then NaN is returned. 
     */
    public static double monthInYear(String datetimeIn)
      throws ParseException
    {
      String[] edz = getEraDatetimeZone(datetimeIn);
      String datetime = edz[1];
      if (datetime == null)
        return Double.NaN;      
      
      String[] formats = {dt, d, gym, gm, gmd};
      return getNumber(datetime, formats, Calendar.MONTH) + 1;
    }
    
    /**
     * See above.
     */
    public static double monthInYear()
    {      
      Calendar cal = Calendar.getInstance();
      return cal.get(Calendar.MONTH) + 1;
   }
    
    /**
     * The date:week-in-year function returns the week of the year as a number. If no argument 
     * is given, then the current local date/time, as returned by date:date-time is used as the 
     * default argument. For the purposes of numbering, counting follows ISO 8601: week 1 in a year 
     * is the week containing the first Thursday of the year, with new weeks beginning on a Monday. 
     * The date/time string specified as the argument is a right-truncated string in the format 
     * defined as the lexical representation of xs:dateTime in one of the formats defined in 
     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>. The 
     * permitted formats are as follows: 
     *    xs:dateTime (CCYY-MM-DDThh:mm:ss) 
     *    xs:date (CCYY-MM-DD) 
     * If the date/time string is not in one of these formats, then NaN is returned. 
     */
    public static double weekInYear(String datetimeIn)
      throws ParseException
    {
      String[] edz = getEraDatetimeZone(datetimeIn);
      String datetime = edz[1];
      if (datetime == null) 
        return Double.NaN;      
      
      String[] formats = {dt, d};
      return getNumber(datetime, formats, Calendar.WEEK_OF_YEAR);
    }
        
    /**
     * See above.
     */
    public static double weekInYear()
    {
       Calendar cal = Calendar.getInstance();
      return cal.get(Calendar.WEEK_OF_YEAR);
   }

    /**
     * The date:day-in-year function returns the day of a date in a year 
     * as a number. If no argument is given, then the current local
     * date/time, as returned by date:date-time is used the default argument.
     * The date/time string specified as the argument is a right-truncated 
     * string in the format defined as the lexical representation of xs:dateTime
     * in one of the formats defined in 
     * <a href="http://www.w3.org/TR/xmlschema-2/">[XML Schema Part 2: Datatypes]</a>. 
     * The permitted formats are as follows:
     *     xs:dateTime (CCYY-MM-DDThh:mm:ss)
     *     xs:date (CCYY-MM-DD) 
     * If the date/time string is not in one of these formats, then NaN is returned. 
     */
    public static double dayInYear(String datetimeIn)
      throws ParseException
    {
      String[] edz = getEraDatetimeZone(datetimeIn);
      String datetime = edz[1];
      if (datetime == null) 
        return Double.NaN;            
      
      String[] formats = {dt, d};
      return getNumber(datetime, formats, Calendar.DAY_OF_YEAR);
    }
    
    /**
     * See above.
     */
    public static double dayInYear()
    {
       Calendar cal = Calendar.getInstance();
      return cal.get(Calendar.DAY_OF_YEAR);
   }
    

    /**