fastdateformat.java

JAVA 文章管理系统源码

            mSize = size;
        }

        public int estimateLength() {
            return 4;
        }

        public void appendTo(StringBuffer buffer, Calendar calendar) {
            appendTo(buffer, calendar.get(mField));
        }

        public final void appendTo(StringBuffer buffer, int value) {
            if (value < 100) {
                for (int i = mSize; --i >= 2; ) {
                    buffer.append('0');
                }
                buffer.append((char)(value / 10 + '0'));
                buffer.append((char)(value % 10 + '0'));
            } else {
                int digits;
                if (value < 1000) {
                    digits = 3;
                } else {
                    digits = (int)(Math.log(value) / LOG_10) + 1;
                }
                for (int i = mSize; --i >= digits; ) {
                    buffer.append('0');
                }
                buffer.append(Integer.toString(value));
            }
        }
    }

    /**
     * <p>Inner class to output a two digit number.</p>
     */
    private static class TwoDigitNumberField implements NumberRule {
        private final int mField;

        TwoDigitNumberField(int field) {
            mField = field;
        }

        public int estimateLength() {
            return 2;
        }

        public void appendTo(StringBuffer buffer, Calendar calendar) {
            appendTo(buffer, calendar.get(mField));
        }

        public final void appendTo(StringBuffer buffer, int value) {
            if (value < 100) {
                buffer.append((char)(value / 10 + '0'));
                buffer.append((char)(value % 10 + '0'));
            } else {
                buffer.append(Integer.toString(value));
            }
        }
    }

    /**
     * <p>Inner class to output a two digit year.</p>
     */
    private static class TwoDigitYearField implements NumberRule {
        static final TwoDigitYearField INSTANCE = new TwoDigitYearField();
        
        TwoDigitYearField() {
        }

        public int estimateLength() {
            return 2;
        }

        public void appendTo(StringBuffer buffer, Calendar calendar) {
            appendTo(buffer, calendar.get(Calendar.YEAR) % 100);
        }

        public final void appendTo(StringBuffer buffer, int value) {
            buffer.append((char)(value / 10 + '0'));
            buffer.append((char)(value % 10 + '0'));
        }
    }

    /**
     * <p>Inner class to output a two digit month.</p>
     */
    private static class TwoDigitMonthField implements NumberRule {
        static final TwoDigitMonthField INSTANCE = new TwoDigitMonthField();
        
        TwoDigitMonthField() {
        }

        public int estimateLength() {
            return 2;
        }

        public void appendTo(StringBuffer buffer, Calendar calendar) {
            appendTo(buffer, calendar.get(Calendar.MONTH) + 1);
        }

        public final void appendTo(StringBuffer buffer, int value) {
            buffer.append((char)(value / 10 + '0'));
            buffer.append((char)(value % 10 + '0'));
        }
    }

    /**
     * <p>Inner class to output the twelve hour field.</p>
     */
    private static class TwelveHourField implements NumberRule {
        private final NumberRule mRule;

        TwelveHourField(NumberRule rule) {
            mRule = rule;
        }

        public int estimateLength() {
            return mRule.estimateLength();
        }

        public void appendTo(StringBuffer buffer, Calendar calendar) {
            int value = calendar.get(Calendar.HOUR);
            if (value == 0) {
                value = calendar.getLeastMaximum(Calendar.HOUR) + 1;
            }
            mRule.appendTo(buffer, value);
        }

        public void appendTo(StringBuffer buffer, int value) {
            mRule.appendTo(buffer, value);
        }
    }

    /**
     * <p>Inner class to output the twenty four hour field.</p>
     */
    private static class TwentyFourHourField implements NumberRule {
        private final NumberRule mRule;

        TwentyFourHourField(NumberRule rule) {
            mRule = rule;
        }

        public int estimateLength() {
            return mRule.estimateLength();
        }

        public void appendTo(StringBuffer buffer, Calendar calendar) {
            int value = calendar.get(Calendar.HOUR_OF_DAY);
            if (value == 0) {
                value = calendar.getMaximum(Calendar.HOUR_OF_DAY) + 1;
            }
            mRule.appendTo(buffer, value);
        }

        public void appendTo(StringBuffer buffer, int value) {
            mRule.appendTo(buffer, value);
        }
    }

    /**
     * <p>Inner class to output a time zone name.</p>
     */
    private static class TimeZoneNameRule implements Rule {
        private final TimeZone mTimeZone;
        private final boolean mTimeZoneForced;
        private final Locale mLocale;
        private final int mStyle;
        private final String mStandard;
        private final String mDaylight;

        TimeZoneNameRule(TimeZone timeZone, boolean timeZoneForced, Locale locale, int style) {
            mTimeZone = timeZone;
            mTimeZoneForced = timeZoneForced;
            mLocale = locale;
            mStyle = style;

            if (timeZoneForced) {
                mStandard = getTimeZoneDisplay(timeZone, false, style, locale);
                mDaylight = getTimeZoneDisplay(timeZone, true, style, locale);
            } else {
                mStandard = null;
                mDaylight = null;
            }
        }

        public int estimateLength() {
            if (mTimeZoneForced) {
                return Math.max(mStandard.length(), mDaylight.length());
            } else if (mStyle == TimeZone.SHORT) {
                return 4;
            } else {
                return 40;
            }
        }

        public void appendTo(StringBuffer buffer, Calendar calendar) {
            if (mTimeZoneForced) {
                if (mTimeZone.useDaylightTime() && calendar.get(Calendar.DST_OFFSET) != 0) {
                    buffer.append(mDaylight);
                } else {
                    buffer.append(mStandard);
                }
            } else {
                TimeZone timeZone = calendar.getTimeZone();
                if (timeZone.useDaylightTime() && calendar.get(Calendar.DST_OFFSET) != 0) {
                    buffer.append(getTimeZoneDisplay(timeZone, true, mStyle, mLocale));
                } else {
                    buffer.append(getTimeZoneDisplay(timeZone, false, mStyle, mLocale));
                }
            }
        }
    }

    /**
     * <p>Inner class to output a time zone as a number <code>+/-HHMM</code>
     * or <code>+/-HH:MM</code>.</p>
     */
    private static class TimeZoneNumberRule implements Rule {
        static final TimeZoneNumberRule INSTANCE_COLON = new TimeZoneNumberRule(true);
        static final TimeZoneNumberRule INSTANCE_NO_COLON = new TimeZoneNumberRule(false);
        
        final boolean mColon;
        
        TimeZoneNumberRule(boolean colon) {
            mColon = colon;
        }

        public int estimateLength() {
            return 5;
        }

        public void appendTo(StringBuffer buffer, Calendar calendar) {
            int offset = calendar.get(Calendar.ZONE_OFFSET) + calendar.get(Calendar.DST_OFFSET);
            
            if (offset < 0) {
                buffer.append('-');
                offset = -offset;
            } else {
                buffer.append('+');
            }
            
            int hours = offset / (60 * 60 * 1000);
            buffer.append((char)(hours / 10 + '0'));
            buffer.append((char)(hours % 10 + '0'));
            
            if (mColon) {
                buffer.append(':');
            }
            
            int minutes = offset / (60 * 1000) - 60 * hours;
            buffer.append((char)(minutes / 10 + '0'));
            buffer.append((char)(minutes % 10 + '0'));
        }            
    }

    // ----------------------------------------------------------------------
    /**
     * <p>Inner class that acts as a compound key for time zone names.</p>
     */
    private static class TimeZoneDisplayKey {
        private final TimeZone mTimeZone;
        private final int mStyle;
        private final Locale mLocale;

        TimeZoneDisplayKey(TimeZone timeZone,
                           boolean daylight, int style, Locale locale) {
            mTimeZone = timeZone;
            if (daylight) {
                style |= 0x80000000;
            }
            mStyle = style;
            mLocale = locale;
        }

        public int hashCode() {
            return mStyle * 31 + mLocale.hashCode();
        }

        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj instanceof TimeZoneDisplayKey) {
                TimeZoneDisplayKey other = (TimeZoneDisplayKey)obj;
                return
                    mTimeZone.equals(other.mTimeZone) &&
                    mStyle == other.mStyle &&
                    mLocale.equals(other.mLocale);
            }
            return false;
        }
    }

    // ----------------------------------------------------------------------
    /**
     * <p>Helper class for creating compound objects.</p>
     *
     * <p>One use for this class is to create a hashtable key
     * out of multiple objects.</p>
     */
    private static class Pair {
        private final Object mObj1;
        private final Object mObj2;

        public Pair(Object obj1, Object obj2) {
            mObj1 = obj1;
            mObj2 = obj2;
        }

        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }

            if (!(obj instanceof Pair)) {
                return false;
            }

            Pair key = (Pair)obj;

            return
                (mObj1 == null ?
                 key.mObj1 == null : mObj1.equals(key.mObj1)) &&
                (mObj2 == null ?
                 key.mObj2 == null : mObj2.equals(key.mObj2));
        }

        public int hashCode() {
            return
                (mObj1 == null ? 0 : mObj1.hashCode()) +
                (mObj2 == null ? 0 : mObj2.hashCode());
        }

        public String toString() {
            return "[" + mObj1 + ':' + mObj2 + ']';
        }
    }

}