java.util.GregorianCalendar#MONTH源码实例Demo

static TimePeriod toTimePeriod(double seconds) {
    if ( seconds >= 36288000 ) {
        return new TimePeriod( GregorianCalendar.YEAR , seconds/3024000 );
    }
    if ( seconds >= 3024000 ) {
        return new TimePeriod( GregorianCalendar.MONTH , seconds/3024000 );
    }
    if ( seconds >= 604800 ) {
        return new TimePeriod( WEEK_FIELD_ID , seconds/604800.0 );
    }
    if ( seconds >= 86400 ) {
        return new TimePeriod( DAY_FIELD_ID , seconds/86400.0 );
    }
    if ( seconds >= 3600 ) {
        return new TimePeriod( HOUR_FIELD_ID , seconds/3600.0 );
    }
    if (seconds >= 60) {
        return new TimePeriod(GregorianCalendar.MINUTE, seconds / 60.0);
    }
    if (seconds >= 1) {
        return new TimePeriod(GregorianCalendar.SECOND, seconds);
    }
    return new TimePeriod(GregorianCalendar.MILLISECOND, 1000*seconds);
}
 

protected int getRecurrenceType()
{
	return GregorianCalendar.MONTH;
}
 

protected int getRecurrenceType()
{
	return GregorianCalendar.MONTH;
}
 

public static Date parse( String s ) {
        if ( s.equals( "" ))
            return null;
        
        Date date = new Date(-1);
        SimpleDateFormat sdf = new SimpleDateFormat();
        sdf.setLenient(false);
        
        String dateText = s;
        int dateShift = 0;
        int shiftBy = GregorianCalendar.DAY_OF_YEAR;
        
        // handles addition of negative numbers
        if ( dateText.matches( ".+\\+.+" ) || dateText.matches( ".+-.+" ) ) {
            String[] sp = new String[] { "", "" };
            int shiftFactor = 1;
            
            if ( dateText.matches( ".+\\+.+" )) {
                sp = dateText.split( "\\+" );    
                shiftFactor = 1;
            }
            // does NOT handle subtract of negative numbers
            else if ( dateText.matches( ".+-.+" ) ) {
                sp = dateText.split( "-" );
                shiftFactor = -1;
                // if we split into two, then there was just one -
                if ( sp.length != 2 )
                    System.err.println( "ERROR(CPSDateValidator): Can't understand date:" +
                                        dateText + " [Too many '-'s]" );
            }
            // trim off leading and trailing whitespace
            dateText = sp[0].trim();
            
            String dateShiftString = sp[1].trim();
            if ( dateShiftString.matches( ".+[dwmy]" )) {
                
                // we match on w or m; trailing whitespace was already trimmed
                // d isn't necessary since it's default
                if ( dateShiftString.matches( ".+w" ))
                    shiftBy = GregorianCalendar.WEEK_OF_YEAR;
                else if ( dateShiftString.matches( ".+m" ))
                    shiftBy = GregorianCalendar.MONTH;
                else if ( dateShiftString.matches( ".+y" ))
                    shiftBy = GregorianCalendar.YEAR;
                
                // trim off the trailing character (the d, w or m)
                dateShiftString = dateShiftString.substring( 0, dateShiftString.length() - 1 );
                
            }
                
            dateShift = shiftFactor * Integer.parseInt( dateShiftString );
        }
        
        
        for ( Integer f : formatList ) {
          String format = getFormat(f);
            sdf.applyPattern( format );
            try {
                // if the date parses, then break the for loop
                date = sdf.parse( dateText );
//                System.out.println("DATE MATCHED: " + format );
                // if the matched format doesn't include a year component, 
                // then shift the date into this year.
                if ( format.indexOf("yy") == -1 ) {
                    GregorianCalendar c = new GregorianCalendar();
                    GregorianCalendar now = new GregorianCalendar();
                    c.setTime( date );
                    now.setTime( new Date() );
                    c.set( GregorianCalendar.YEAR, now.get( GregorianCalendar.YEAR ) );
                    date = c.getTime();
                }
                break;
            } 
            // if the date doesn't parse, try the next pattern
            catch ( Exception ignore ) {}
            System.err.println( "ERROR parsing date: " + s );
        }
        
        // if dateShift is not 0, then we should add it to the parsed date
        if ( dateShift != 0 ) {
            GregorianCalendar cal = new GregorianCalendar();
            cal.setTime( date );
            cal.add( shiftBy, dateShift );
            date = cal.getTime();
        }
        
        return date;
    }
 

static void round(GregorianCalendar cal, int field) {

        if (GregorianCalendar.MILLISECOND == field) {
            return;
        }
        cal.set(GregorianCalendar.MILLISECOND, 0);

        if (GregorianCalendar.SECOND == field) {
            return;
        }
        cal.set(GregorianCalendar.SECOND, 0);

        if (GregorianCalendar.MINUTE == field) {
            return;
        }
        cal.set(GregorianCalendar.MINUTE, 0);

        if ( HOUR_FIELD_ID == field ) {
            return;
        }
        cal.set( HOUR_FIELD_ID , FIRST_HOUR );

        if ( DAY_FIELD_ID == field ) {
            return;
        }
        cal.set(DAY_FIELD_ID , FIRST_DAY );

        if ( WEEK_FIELD_ID == field ) {
            return;
        }

        //here, we are rounding down to the first week (i.e. the first day of
        //the month), so the day of the week and the week of the month no
        //longer matter - we just set the day to be the first day of the month
        cal.set( GregorianCalendar.DAY_OF_MONTH , 1 );

        if ( GregorianCalendar.MONTH == field ) {
            return;
        }

        cal.set( GregorianCalendar.MONTH , 0 );

        if ( GregorianCalendar.YEAR == field ) {
            return;
        }
        cal.set( GregorianCalendar.YEAR , 0 );

    }