datetimeconverter.java

APACHE 公司出的java bean 工具包

        // Handle Long
        if (value instanceof Long) {
            Long longObj = (Long)value;
            return toDate(targetType, longObj.longValue());
        }

        // Convert all other types to String & handle
        String stringValue = value.toString().trim();
        if (stringValue.length() == 0) {
            return handleMissing(targetType);
        }

        // Parse the Date/Time
        if (useLocaleFormat) {
            Calendar calendar = null;
            if (patterns != null && patterns.length > 0) {
                calendar = parse(sourceType, targetType, stringValue);
            } else {
                DateFormat format = getFormat(locale, timeZone);
                calendar = parse(sourceType, targetType, stringValue, format);
            }
            if (Calendar.class.isAssignableFrom(targetType)) {
                return calendar;
            } else {
                return toDate(targetType, calendar.getTime().getTime());
            }
        }

        // Default String conversion
        return toDate(targetType, stringValue);

    }

    /**
     * Convert a long value to the specified Date type for this
     * <i>Converter</i>.
     * <p>
     *
     * This method handles conversion to the following types:
     * <ul>
     *     <li><code>java.util.Date</code></li>
     *     <li><code>java.util.Calendar</code></li>
     *     <li><code>java.sql.Date</code></li>
     *     <li><code>java.sql.Time</code></li>
     *     <li><code>java.sql.Timestamp</code></li>
     * </ul>
     *
     * @param type The Date type to convert to
     * @param value The long value to convert.
     * @return The converted date value.
     */
    private Object toDate(Class type, long value) {

        // java.util.Date
        if (type.equals(Date.class)) {
            return new Date(value);
        }

        // java.sql.Date
        if (type.equals(java.sql.Date.class)) {
            return new java.sql.Date(value);
        }

        // java.sql.Time
        if (type.equals(java.sql.Time.class)) {
            return new java.sql.Time(value);
        }

        // java.sql.Timestamp
        if (type.equals(java.sql.Timestamp.class)) {
            return new java.sql.Timestamp(value);
        }

        // java.util.Calendar
        if (type.equals(Calendar.class)) {
            Calendar calendar = null;
            if (locale == null && timeZone == null) {
                calendar = Calendar.getInstance();
            } else if (locale == null) {
                calendar = Calendar.getInstance(timeZone);
            } else if (timeZone == null) {
                calendar = Calendar.getInstance(locale);
            } else {
                calendar = Calendar.getInstance(timeZone, locale);
            }
            calendar.setTime(new Date(value));
            calendar.setLenient(false);
            return calendar;
        }

        String msg = toString(getClass()) + " cannot handle conversion to '"
                   + toString(type) + "'";
        if (log().isWarnEnabled()) {
            log().warn("    " + msg);
        }
        throw new ConversionException(msg);
    }

    /**
     * Default String to Date conversion.
     * <p>
     * This method handles conversion from a String to the following types:
     * <ul>
     *     <li><code>java.sql.Date</code></li>
     *     <li><code>java.sql.Time</code></li>
     *     <li><code>java.sql.Timestamp</code></li>
     * </ul>
     * <p>
     * <strong>N.B.</strong> No default String conversion
     * mechanism is provided for <code>java.util.Date</code>
     * and <code>java.util.Calendar</code> type.
     *
     * @param type The Number type to convert to
     * @param value The String value to convert.
     * @return The converted Number value.
     */
    private Object toDate(Class type, String value) {
        // java.sql.Date
        if (type.equals(java.sql.Date.class)) {
            try {
                return java.sql.Date.valueOf(value);
            } catch (IllegalArgumentException e) {
                throw new ConversionException(
                        "String must be in JDBC format [yyyy-MM-dd] to create a java.sql.Date");
            }
        }

        // java.sql.Time
        if (type.equals(java.sql.Time.class)) {
            try {
                return java.sql.Time.valueOf(value);
            } catch (IllegalArgumentException e) {
                throw new ConversionException(
                        "String must be in JDBC format [HH:mm:ss] to create a java.sql.Time");
            }
        }

        // java.sql.Timestamp
        if (type.equals(java.sql.Timestamp.class)) {
            try {
                return java.sql.Timestamp.valueOf(value);
            } catch (IllegalArgumentException e) {
                throw new ConversionException(
                        "String must be in JDBC format [yyyy-MM-dd HH:mm:ss.fffffffff] " +
                        "to create a java.sql.Timestamp");
            }
        }

        String msg = toString(getClass()) + " does not support default String to '"
                   + toString(type) + "' conversion.";
        if (log().isWarnEnabled()) {
            log().warn("    " + msg);
            log().warn("    (N.B. Re-configure Converter or use alternative implementation)");
        }
        throw new ConversionException(msg);
    }

    /**
     * Return a <code>DateFormat<code> for the Locale.
     * @param locale The Locale to create the Format with (may be null)
     * @param timeZone The Time Zone create the Format with (may be null)
     *
     * @return A Date Format.
     */
    protected DateFormat getFormat(Locale locale, TimeZone timeZone) {
        DateFormat format = null;
        if (locale == null) {
            format = DateFormat.getDateInstance(DateFormat.SHORT);
        } else {
            format = DateFormat.getDateInstance(DateFormat.SHORT, locale);
        }
        if (timeZone != null) {
            format.setTimeZone(timeZone);
        }
        return format;
    }

    /**
     * Create a date format for the specified pattern.
     *
     * @param pattern The date pattern
     * @return The DateFormat
     */
    private DateFormat getFormat(String pattern) {
        DateFormat format = new SimpleDateFormat(pattern);
        if (timeZone != null) {
            format.setTimeZone(timeZone);
        }
        return format;
    }

    /**
     * Parse a String date value using the set of patterns.
     *
     * @param sourceType The type of the value being converted
     * @param targetType The type to convert the value to.
     * @param value The String date value.
     *
     * @return The converted Date object.
     * @throws Exception if an error occurs parsing the date.
     */
    private Calendar parse(Class sourceType, Class targetType, String value) throws Exception {
        Exception firstEx = null;
        for (int i = 0; i < patterns.length; i++) {
            try {
                DateFormat format = getFormat(patterns[i]);
                Calendar calendar = parse(sourceType, targetType, value, format);
                return calendar;
            } catch (Exception ex) {
                if (firstEx == null) {
                    firstEx = ex;
                }
            }
        }
        if (patterns.length > 1) {
            throw new ConversionException("Error converting '" + toString(sourceType) + "' to '" + toString(targetType)
                    + "' using  patterns '" + displayPatterns + "'");
        } else {
            throw firstEx;
        }
    }

    /**
     * Parse a String into a <code>Calendar</code> object
     * using the specified <code>DateFormat</code>.
     *
     * @param sourceType The type of the value being converted
     * @param targetType The type to convert the value to
     * @param value The String date value.
     * @param format The DateFormat to parse the String value.
     *
     * @return The converted Calendar object.
     * @throws ConversionException if the String cannot be converted.
     */
    private Calendar parse(Class sourceType, Class targetType, String value, DateFormat format) {
        logFormat("Parsing", format);
        format.setLenient(false);
        ParsePosition pos = new ParsePosition(0);
        Date parsedDate = format.parse(value, pos); // ignore the result (use the Calendar)
        if (pos.getErrorIndex() >= 0 || pos.getIndex() != value.length() || parsedDate == null) {
            String msg = "Error converting '" + toString(sourceType) + "' to '" + toString(targetType) + "'";
            if (format instanceof SimpleDateFormat) {
                msg += " using pattern '" + ((SimpleDateFormat)format).toPattern() + "'";
            }
            if (log().isDebugEnabled()) {
                log().debug("    " + msg);
            }
            throw new ConversionException(msg);
        }
        Calendar calendar = format.getCalendar();
        return calendar;
    }

    /**
     * Provide a String representation of this date/time converter.
     *
     * @return A String representation of this date/time converter
     */
    public String toString() {
        StringBuffer buffer = new StringBuffer();
        buffer.append(toString(getClass()));
        buffer.append("[UseDefault=");
        buffer.append(isUseDefault());
        buffer.append(", UseLocaleFormat=");
        buffer.append(useLocaleFormat);
        if (displayPatterns != null) {
            buffer.append(", Patterns={");
            buffer.append(displayPatterns);
            buffer.append('}');
        }
        if (locale != null) {
            buffer.append(", Locale=");
            buffer.append(locale);
        }
        if (timeZone != null) {
            buffer.append(", TimeZone=");
            buffer.append(timeZone);
        }
        buffer.append(']');
        return buffer.toString();
    }

    /**
     * Log the <code>DateFormat<code> creation.
     * @param action The action the format is being used for
     * @param format The Date format
     */
    private void logFormat(String action, DateFormat format) {
        if (log().isDebugEnabled()) {
            StringBuffer buffer = new StringBuffer(45);
            buffer.append("    ");
            buffer.append(action);
            buffer.append(" with Format");
            if (format instanceof SimpleDateFormat) {
                buffer.append("[");
                buffer.append(((SimpleDateFormat)format).toPattern());
                buffer.append("]");
            }
            buffer.append(" for ");
            if (locale == null) {
                buffer.append("default locale");
            } else {
                buffer.append("locale[");
                buffer.append(locale);
                buffer.append("]");
            }
            if (timeZone != null) {
                buffer.append(", TimeZone[");
                buffer.append(timeZone);
                buffer.append("]");
            }
            log().debug(buffer.toString());
        }
    }
}