timeutil.java

开发MySql数据库的最新JDBC驱动。

	
				int fromOffset = fromCal.get(Calendar.ZONE_OFFSET)
						+ fromCal.get(Calendar.DST_OFFSET);
				Calendar toCal = Calendar.getInstance(toTz);
				toCal.setTime(tstamp);
	
				int toOffset = toCal.get(Calendar.ZONE_OFFSET)
						+ toCal.get(Calendar.DST_OFFSET);
				int offsetDiff = fromOffset - toOffset;
				long toTime = toCal.getTime().getTime();
	
				if (rollForward || (conn.isServerTzUTC() && !conn.isClientTzUTC())) {
					toTime += offsetDiff;
				} else {
					toTime -= offsetDiff;
				}
	
				Timestamp changedTimestamp = new Timestamp(toTime);
	
				return changedTimestamp;
			} else if (conn.getUseJDBCCompliantTimezoneShift()) {
				if (targetCalendar != null) {

					Timestamp adjustedTimestamp = new Timestamp( 
							jdbcCompliantZoneShift(sessionCalendar, 
									targetCalendar, tstamp));
					
					adjustedTimestamp.setNanos(tstamp.getNanos());
					
					return adjustedTimestamp;
				}
			}
		}
		
		return tstamp;
	}

	private static long jdbcCompliantZoneShift(Calendar sessionCalendar, 
			Calendar targetCalendar, 
			java.util.Date dt) {
		if (sessionCalendar == null) {
			sessionCalendar = new GregorianCalendar();
		}
		
		// JDBC spec is not clear whether or not this 
		// calendar should be immutable, so let's treat
		// it like it is, for safety
		
		java.util.Date origCalDate = targetCalendar.getTime();
		java.util.Date origSessionDate = sessionCalendar.getTime();
		
		try {
			sessionCalendar.setTime(dt);
			
			targetCalendar.set(Calendar.YEAR, sessionCalendar.get(Calendar.YEAR));
			targetCalendar.set(Calendar.MONTH, sessionCalendar.get(Calendar.MONTH));
			targetCalendar.set(Calendar.DAY_OF_MONTH, sessionCalendar.get(Calendar.DAY_OF_MONTH));

			targetCalendar.set(Calendar.HOUR_OF_DAY, sessionCalendar.get(Calendar.HOUR_OF_DAY));                
			targetCalendar.set(Calendar.MINUTE, sessionCalendar.get(Calendar.MINUTE));
			targetCalendar.set(Calendar.SECOND, sessionCalendar.get(Calendar.SECOND));
			targetCalendar.set(Calendar.MILLISECOND, sessionCalendar.get(Calendar.MILLISECOND));                
			
			return targetCalendar.getTime().getTime();
			
		} finally {
			sessionCalendar.setTime(origSessionDate);
			targetCalendar.setTime(origCalDate);
		}
	}

	//
	// WARN! You must externally synchronize these calendar instances
	// See ResultSet.fastDateCreate() for an example
	//
	final static Date fastDateCreate(boolean useGmtConversion,
			Calendar gmtCalIfNeeded,
			Calendar cal, int year, int month, int day) {
		
		Calendar dateCal = cal;
		
		if (useGmtConversion) {
			
			if (gmtCalIfNeeded == null) {
				gmtCalIfNeeded = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
			}
			gmtCalIfNeeded.clear();
			
			dateCal = gmtCalIfNeeded;
		}
		
		dateCal.clear();

		// why-oh-why is this different than java.util.date,
		// in the year part, but it still keeps the silly '0'
		// for the start month????
		dateCal.set(year, month - 1, day, 0, 0, 0);
		
		long dateAsMillis = 0;

		try {
			dateAsMillis = dateCal.getTimeInMillis();
		} catch (IllegalAccessError iae) {
			// Must be on JDK-1.3.1 or older....
			dateAsMillis = dateCal.getTime().getTime();
		}

		return new Date(dateAsMillis);
	}

	final static Time fastTimeCreate(Calendar cal, int hour, int minute,
			int second) throws SQLException {
		if (hour < 0 || hour > 23) {
			throw SQLError.createSQLException("Illegal hour value '" + hour + "' for java.sql.Time type in value '"
					+ timeFormattedString(hour, minute, second) + ".", 
					SQLError.SQL_STATE_ILLEGAL_ARGUMENT);
		}
		
		if (minute < 0 || minute > 59) {
			throw SQLError.createSQLException("Illegal minute value '" + minute + "'" + "' for java.sql.Time type in value '"
					+ timeFormattedString(hour, minute, second) + ".", 
					SQLError.SQL_STATE_ILLEGAL_ARGUMENT);
		}
		
		if (second < 0 || second > 59) {
			throw SQLError.createSQLException("Illegal minute value '" + second + "'" + "' for java.sql.Time type in value '"
					+ timeFormattedString(hour, minute, second) + ".", 
					SQLError.SQL_STATE_ILLEGAL_ARGUMENT);
		}
		
		cal.clear();

		// Set 'date' to epoch of Jan 1, 1970
		cal.set(1970, 0, 1, hour, minute, second);

		long timeAsMillis = 0;

		try {
			timeAsMillis = cal.getTimeInMillis();
		} catch (IllegalAccessError iae) {
			// Must be on JDK-1.3.1 or older....
			timeAsMillis = cal.getTime().getTime();
		}

		return new Time(timeAsMillis);
	}

	final static Timestamp fastTimestampCreate(boolean useGmtConversion,
			Calendar gmtCalIfNeeded,
			Calendar cal, int year,
			int month, int day, int hour, int minute, int seconds,
			int secondsPart) {
		cal.clear();

		// why-oh-why is this different than java.util.date,
		// in the year part, but it still keeps the silly '0'
		// for the start month????
		cal.set(year, month - 1, day, hour, minute, seconds);

		int offsetDiff = 0;
		
		if (useGmtConversion) {
			int fromOffset = cal.get(Calendar.ZONE_OFFSET)
			+ cal.get(Calendar.DST_OFFSET);
			
			if (gmtCalIfNeeded == null) {
				gmtCalIfNeeded = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
			}
			gmtCalIfNeeded.clear();
			
			gmtCalIfNeeded.setTimeInMillis(cal.getTimeInMillis());
	
			int toOffset = gmtCalIfNeeded.get(Calendar.ZONE_OFFSET)
				+ gmtCalIfNeeded.get(Calendar.DST_OFFSET);
			offsetDiff = fromOffset - toOffset;
		}

		long tsAsMillis = 0;

		try {
			tsAsMillis = cal.getTimeInMillis();
		} catch (IllegalAccessError iae) {
			// Must be on JDK-1.3.1 or older....
			tsAsMillis = cal.getTime().getTime();
		}

		Timestamp ts = new Timestamp(tsAsMillis + offsetDiff);
		ts.setNanos(secondsPart);

		return ts;
	}

	/**
	 * Returns the 'official' Java timezone name for the given timezone
	 * 
	 * @param timezoneStr
	 *            the 'common' timezone name
	 * 
	 * @return the Java timezone name for the given timezone
	 * 
	 * @throws IllegalArgumentException
	 *             DOCUMENT ME!
	 */
	public static String getCanoncialTimezone(String timezoneStr) {
		if (timezoneStr == null) {
			return null;
		}

		timezoneStr = timezoneStr.trim();

		// Fix windows Daylight/Standard shift JDK doesn't map these (doh)

		int daylightIndex = StringUtils.indexOfIgnoreCase(timezoneStr,
				"DAYLIGHT");

		if (daylightIndex != -1) {
			StringBuffer timezoneBuf = new StringBuffer();
			timezoneBuf.append(timezoneStr.substring(0, daylightIndex));
			timezoneBuf.append("Standard");
			timezoneBuf.append(timezoneStr.substring(daylightIndex
					+ "DAYLIGHT".length(), timezoneStr.length()));
			timezoneStr = timezoneBuf.toString();
		}

		String canonicalTz = (String) TIMEZONE_MAPPINGS.get(timezoneStr);

		// if we didn't find it, try abbreviated timezones
		if (canonicalTz == null) {
			String[] abbreviatedTimezone = (String[]) ABBREVIATED_TIMEZONES
					.get(timezoneStr);

			if (abbreviatedTimezone != null) {
				// If there's only one mapping use that
				if (abbreviatedTimezone.length == 1) {
					canonicalTz = abbreviatedTimezone[0];
				} else {
					StringBuffer errorMsg = new StringBuffer(
							"The server timezone value '");
					errorMsg.append(timezoneStr);
					errorMsg
							.append("' represents more than one timezone. You must ");
					errorMsg
							.append("configure either the server or client to use a ");
					errorMsg
							.append("more specifc timezone value if you want to enable ");
					errorMsg.append("timezone support. The timezones that '");
					errorMsg.append(timezoneStr);
					errorMsg.append("' maps to are: ");
					errorMsg.append(abbreviatedTimezone[0]);

					for (int i = 1; i < abbreviatedTimezone.length; i++) {
						errorMsg.append(", ");
						errorMsg.append(abbreviatedTimezone[i]);
					}

					throw new IllegalArgumentException(errorMsg.toString());
				}
			}
		}

		return canonicalTz;
	}
	
	// we could use SimpleDateFormat, but it won't work when the time values
	// are out-of-bounds, and we're using this for error messages for exactly 
	// that case
	//
	
	private static String timeFormattedString(int hours, int minutes, int seconds) {
		StringBuffer buf = new StringBuffer(8);
		
		if (hours < 10) {
			buf.append("0");
		}
		
		buf.append(hours);
		buf.append(":");
		
		if (minutes < 10) {
			buf.append("0");
		}
		
		buf.append(minutes);
		buf.append(":");
		
		if (seconds < 10) {
			buf.append("0");
		}
		
		buf.append(seconds);
		
		return buf.toString();
	}
}