fastdateformat.java

JAVA 文章管理系统源码

     * 
     * @param date  the date to format
     * @return the formatted string
     */
    public String format(Date date) {
        Calendar c = new GregorianCalendar(mTimeZone);
        c.setTime(date);
        return applyRules(c, new StringBuffer(mMaxLengthEstimate)).toString();
    }

    /**
     * <p>Formats a <code>Calendar</code> object.</p>
     * 
     * @param calendar  the calendar to format
     * @return the formatted string
     */
    public String format(Calendar calendar) {
        return format(calendar, new StringBuffer(mMaxLengthEstimate)).toString();
    }

    /**
     * <p>Formats a <code>Date</code> object into the
     * supplied <code>StringBuffer</code>.</p>
     * 
     * @param date  the date to format
     * @param buf  the buffer to format into
     * @return the specified string buffer
     */
    public StringBuffer format(Date date, StringBuffer buf) {
        Calendar c = new GregorianCalendar(mTimeZone);
        c.setTime(date);
        return applyRules(c, buf);
    }

    /**
     * <p>Formats a <code>Calendar</code> object into the
     * supplied <code>StringBuffer</code>.</p>
     * 
     * @param calendar  the calendar to format
     * @param buf  the buffer to format into
     * @return the specified string buffer
     */
    public StringBuffer format(Calendar calendar, StringBuffer buf) {
        if (mTimeZoneForced) {
            calendar = (Calendar) calendar.clone();
            calendar.setTimeZone(mTimeZone);
        }
        return applyRules(calendar, buf);
    }

    /**
     * <p>Performs the formatting by applying the rules to the
     * specified calendar.</p>
     * 
     * @param calendar  the calendar to format
     * @param buf  the buffer to format into
     * @return the specified string buffer
     */
    protected StringBuffer applyRules(Calendar calendar, StringBuffer buf) {
        Rule[] rules = mRules;
        int len = mRules.length;
        for (int i = 0; i < len; i++) {
            rules[i].appendTo(buf, calendar);
        }
        return buf;
    }

    // Parsing
    //-----------------------------------------------------------------------
    /**
     * <p>Parsing not supported.</p>
     * 
     * @param source  the string to parse
     * @param pos  the parsing position
     * @return <code>null</code> as not supported
     */
    public Object parseObject(String source, ParsePosition pos) {
        pos.setIndex(0);
        pos.setErrorIndex(0);
        return null;
    }
    
    // Accessors
    //-----------------------------------------------------------------------
    /**
     * <p>Gets the pattern used by this formatter.</p>
     * 
     * @return the pattern, {@link java.text.SimpleDateFormat} compatible
     */
    public String getPattern() {
        return mPattern;
    }

    /**
     * <p>Gets the time zone used by this formatter.</p>
     *
     * <p>This zone is always used for <code>Date</code> formatting.
     * If a <code>Calendar</code> is passed in to be formatted, the
     * time zone on that may be used depending on
     * {@link #getTimeZoneOverridesCalendar()}.</p>
     * 
     * @return the time zone
     */
    public TimeZone getTimeZone() {
        return mTimeZone;
    }

    /**
     * <p>Returns <code>true</code> if the time zone of the
     * calendar overrides the time zone of the formatter.</p>
     * 
     * @return <code>true</code> if time zone of formatter
     *  overridden for calendars
     */
    public boolean getTimeZoneOverridesCalendar() {
        return mTimeZoneForced;
    }

    /**
     * <p>Gets the locale used by this formatter.</p>
     * 
     * @return the locale
     */
    public Locale getLocale() {
        return mLocale;
    }

    /**
     * <p>Gets  an estimate for the maximum string length that the
     * formatter will produce.</p>
     *
     * <p>The actual formatted length will almost always be less than or
     * equal to this amount.</p>
     * 
     * @return the maximum formatted length
     */
    public int getMaxLengthEstimate() {
        return mMaxLengthEstimate;
    }

    // Basics
    //-----------------------------------------------------------------------
    /**
     * <p>Compare two objects for equality.</p>
     * 
     * @param obj  the object to compare to
     * @return <code>true</code> if equal
     */
    public boolean equals(Object obj) {
        if (obj instanceof FastDateFormat == false) {
            return false;
        }
        FastDateFormat other = (FastDateFormat) obj;
        if (
            (mPattern == other.mPattern || mPattern.equals(other.mPattern)) &&
            (mTimeZone == other.mTimeZone || mTimeZone.equals(other.mTimeZone)) &&
            (mLocale == other.mLocale || mLocale.equals(other.mLocale)) &&
            (mTimeZoneForced == other.mTimeZoneForced) &&
            (mLocaleForced == other.mLocaleForced)
            ) {
            return true;
        }
        return false;
    }

    /**
     * <p>A suitable hashcode.</p>
     * 
     * @return a hashcode compatable with equals
     */
    public int hashCode() {
        int total = 0;
        total += mPattern.hashCode();
        total += mTimeZone.hashCode();
        total += (mTimeZoneForced ? 1 : 0);
        total += mLocale.hashCode();
        total += (mLocaleForced ? 1 : 0);
        return total;
    }

    /**
     * <p>Gets a debugging string version of this formatter.</p>
     * 
     * @return a debugging string
     */
    public String toString() {
        return "FastDateFormat[" + mPattern + "]";
    }
    
    // Rules
    //-----------------------------------------------------------------------
    /**
     * <p>Inner class defining a rule.</p>
     */
    private interface Rule {
        int estimateLength();
        void appendTo(StringBuffer buffer, Calendar calendar);
    }

    /**
     * <p>Inner class defining a numeric rule.</p>
     */
    private interface NumberRule extends Rule {
        void appendTo(StringBuffer buffer, int value);
    }

    /**
     * <p>Inner class to output a constant single character.</p>
     */
    private static class CharacterLiteral implements Rule {
        private final char mValue;

        CharacterLiteral(char value) {
            mValue = value;
        }

        public int estimateLength() {
            return 1;
        }

        public void appendTo(StringBuffer buffer, Calendar calendar) {
            buffer.append(mValue);
        }
    }

    /**
     * <p>Inner class to output a constant string.</p>
     */
    private static class StringLiteral implements Rule {
        private final String mValue;

        StringLiteral(String value) {
            mValue = value;
        }

        public int estimateLength() {
            return mValue.length();
        }

        public void appendTo(StringBuffer buffer, Calendar calendar) {
            buffer.append(mValue);
        }
    }

    /**
     * <p>Inner class to output one of a set of values.</p>
     */
    private static class TextField implements Rule {
        private final int mField;
        private final String[] mValues;

        TextField(int field, String[] values) {
            mField = field;
            mValues = values;
        }

        public int estimateLength() {
            int max = 0;
            for (int i=mValues.length; --i >= 0; ) {
                int len = mValues[i].length();
                if (len > max) {
                    max = len;
                }
            }
            return max;
        }

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

    /**
     * <p>Inner class to output an unpadded number.</p>
     */
    private static class UnpaddedNumberField implements NumberRule {
        static final UnpaddedNumberField INSTANCE_YEAR = new UnpaddedNumberField(Calendar.YEAR);
        
        private final int mField;

        UnpaddedNumberField(int field) {
            mField = field;
        }

        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 < 10) {
                buffer.append((char)(value + '0'));
            } else 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 an unpadded month.</p>
     */
    private static class UnpaddedMonthField implements NumberRule {
        static final UnpaddedMonthField INSTANCE = new UnpaddedMonthField();
        
        UnpaddedMonthField() {
        }

        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) {
            if (value < 10) {
                buffer.append((char)(value + '0'));
            } else {
                buffer.append((char)(value / 10 + '0'));
                buffer.append((char)(value % 10 + '0'));
            }
        }
    }

    /**
     * <p>Inner class to output a padded number.</p>
     */
    private static class PaddedNumberField implements NumberRule {
        private final int mField;
        private final int mSize;

        PaddedNumberField(int field, int size) {
            if (size < 3) {
                // Should use UnpaddedNumberField or TwoDigitNumberField.
                throw new IllegalArgumentException();
            }
            mField = field;