exsltdatetime.java

来自「java jdk 1.4的源码」· Java 代码 · 共 958 行 · 第 1/3 页

     * See above.
     */
    public static XBoolean leapYear()
    {
      Calendar cal = Calendar.getInstance();
      int yr = (int)cal.get(Calendar.YEAR);
      return new XBoolean(yr % 400 == 0 || (yr % 100 != 0 && yr % 4 == 0));      
    }    
       
    /**
     * The date:month-name function returns the full name of the month of a date. 
     * 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 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--) 
     * If the date/time string is not in one of these formats, then an empty string ('') 
     * is returned. 
     * The result is an English month name: one of 'January', 'February', 'March', 
     * 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November' 
     * or 'December'. 
     */
    public static XString monthName(String datetimeIn)
      throws ParseException
    {
      String[] edz = getEraDatetimeZone(datetimeIn);
      String datetime = edz[1];
      if (datetime == null) 
        return new XString("");
      
      String[] formatsIn = {dt, d, gym, gm};
      String formatOut = "MMMM";
      return new XString (getNameOrAbbrev(datetimeIn, formatsIn, formatOut));    
    }
    
    /**
     * See above.
     */
    public static XString monthName()
    {
      Calendar cal = Calendar.getInstance();
      String format = "MMMM";
      return new XString(getNameOrAbbrev(format));  
    }
        
    /**
     * The date:month-abbreviation function returns the abbreviation of the month of 
     * a date. 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 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--) 
     * If the date/time string is not in one of these formats, then an empty string ('') 
     * is returned. 
     * The result is a three-letter English month abbreviation: one of 'Jan', 'Feb', 'Mar', 
     * 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov' or 'Dec'. 
     * An implementation of this extension function in the EXSLT date namespace must conform 
     * to the behaviour described in this document. 
     */
    public static XString monthAbbreviation(String datetimeIn)
      throws ParseException
    {
      String[] edz = getEraDatetimeZone(datetimeIn);
      String datetime = edz[1];
      if (datetime == null) 
        return new XString("");
      
      String[] formatsIn = {dt, d, gym, gm};
      String formatOut = "MMM";
      return new XString (getNameOrAbbrev(datetimeIn, formatsIn, formatOut));
    }
    
    /**
     * See above.
     */
    public static XString monthAbbreviation()
    {
      String format = "MMM";
      return new XString(getNameOrAbbrev(format));  
    }
        
    /**
     * The date:day-name function returns the full name of the day of the week 
     * of a date.  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 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) 
     * If the date/time string is not in one of these formats, then the empty string ('') 
     * is returned. 
     * The result is an English day name: one of 'Sunday', 'Monday', 'Tuesday', 'Wednesday', 
     * 'Thursday' or 'Friday'. 
     * An implementation of this extension function in the EXSLT date namespace must conform 
     * to the behaviour described in this document. 
     */
    public static XString dayName(String datetimeIn)
      throws ParseException
    {
      String[] edz = getEraDatetimeZone(datetimeIn);
      String datetime = edz[1];
      if (datetime == null) 
        return new XString("");
            
      String[] formatsIn = {dt, d};
      String formatOut = "EEEE";
      return new XString (getNameOrAbbrev(datetimeIn, formatsIn, formatOut));    
    }
    
    /**
     * See above.
     */
    public static XString dayName()
    {
      String format = "EEEE";
      return new XString(getNameOrAbbrev(format));        
    }    
    
    /**
     * The date:day-abbreviation function returns the abbreviation of the day 
     * of the week of a date. 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 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) 
     * If the date/time string is not in one of these formats, then the empty string 
     * ('') is returned. 
     * The result is a three-letter English day abbreviation: one of 'Sun', 'Mon', 'Tue', 
     * 'Wed', 'Thu' or 'Fri'. 
     * An implementation of this extension function in the EXSLT date namespace must conform 
     * to the behaviour described in this document. 
     */
    public static XString dayAbbreviation(String datetimeIn)
      throws ParseException
    {
      String[] edz = getEraDatetimeZone(datetimeIn);
      String datetime = edz[1];
      if (datetime == null) 
        return new XString("");            
      
      String[] formatsIn = {dt, d};
      String formatOut = "EEE";
      return new XString (getNameOrAbbrev(datetimeIn, formatsIn, formatOut));
    }
    
    /**
     * See above.
     */
    public static XString dayAbbreviation()
    {
      String format = "EEE";
      return new XString(getNameOrAbbrev(format));              
    }
    
    /**
     * Returns an array with the 3 components that a datetime input string 
     * may contain: - (for BC era), datetime, and zone. If the zone is not
     * valid, return null for that component.
     */
    private static String[] getEraDatetimeZone(String in)
    {
      String leader = "";
      String datetime = in;
      String zone = "";
      if (in.charAt(0)=='-')
      {
        leader = "-"; //  '+' is implicit , not allowed
        datetime = in.substring(1);
      }
      int z = getZoneStart(datetime);
      if (z > 0)
      {
        zone = datetime.substring(z);
        datetime = datetime.substring(0, z);
      }
      else if (z == -2)
        zone = null;
      //System.out.println("'" + leader + "' " + datetime + " " + zone);
      return new String[]{leader, datetime, zone};  
    }    
    
    /**
     * Get the start of zone information if the input ends
     * with 'Z' or +/-hh:mm. If a zone string is not
     * found, return -1; if the zone string is invalid,
     * return -2.
     */
    private static int getZoneStart (String datetime)
    {
      if (datetime.indexOf("Z") == datetime.length()-1)
        return datetime.indexOf("Z");
      else if (
               (datetime.lastIndexOf("-") == datetime.length()-6 &&
                datetime.charAt(datetime.length()-3) == ':')               
                || 
                (datetime.indexOf("+") == datetime.length() -6)
              )
      {
        try
        {
          SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm");
          dateFormat.setLenient(false);
          Date d = dateFormat.parse(datetime.substring(datetime.length() -5));
          return datetime.length()-6;
        }
        catch (ParseException pe)
        {
          System.out.println("ParseException " + pe.getErrorOffset());
          return -2; // Invalid.
        }

      }
        return -1; // No zone information.
    }
    
    /**
     * Attempt to parse an input string with the allowed formats, returning
     * null if none of the formats work. Input formats are passed in longest to shortest,
     * so if any parse operation fails with a parse error in the string, can
     * immediately return null.
     */
    private static Date testFormats (String in, String[] formats)
      throws ParseException
    {
      for (int i = 0; i <formats.length; i++)
      {
        try
        {
          SimpleDateFormat dateFormat = new SimpleDateFormat(formats[i]);
          dateFormat.setLenient(false);          
          return dateFormat.parse(in);
        }
        catch (ParseException pe)
        {
          if (pe.getErrorOffset() < in.length())
            return null;
        }
      }
      return null;
    }
    
    
    /**
     * Parse the input string and return the corresponding calendar field
     * number.
     */
    private static double getNumber(String in, String[] formats, int calField)
      throws ParseException
    {
      Calendar cal = Calendar.getInstance();
      cal.setLenient(false);
      // Try the allowed formats, from longest to shortest.
      Date date = testFormats(in, formats);
      if (date == null) return Double.NaN;
      cal.setTime(date);
      return cal.get(calField);
    }    
     
    /**
     *  Get the full name or abbreviation of the month or day.
     */
    private static String getNameOrAbbrev(String in, 
                                         String[] formatsIn,
                                         String formatOut)
      throws ParseException
    {
      for (int i = 0; i <formatsIn.length; i++) // from longest to shortest.
      {
        try
        {
          SimpleDateFormat dateFormat = new SimpleDateFormat(formatsIn[i]);
          dateFormat.setLenient(false);
          Date dt = dateFormat.parse(in);          
          dateFormat.applyPattern(formatOut);
          return dateFormat.format(dt);
        }
        catch (ParseException pe)
        {
          // If ParseException occurred during input string, input is invalid.
          // If the ParseException occurred at the end of the input string,
          // another format may work.
          if (pe.getErrorOffset() < in.length())
            return "";
        }
      }
      return "";
    }
    /**
     * Get the full name or abbreviation for the current month or day 
     * (no input string).
     */
    private static String getNameOrAbbrev(String format)
    {
      Calendar cal = Calendar.getInstance();
      SimpleDateFormat dateFormat = new SimpleDateFormat(format);
      return dateFormat.format(cal.getTime());
    }

}