timestamp.java

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/*
 * @(#)Timestamp.java	1.53 03/01/27
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package java.sql;

/**
 * <P>A thin wrapper around <code>java.util.Date</code> that allows
 * the JDBC API to identify this as an SQL <code>TIMESTAMP</code> value.
 * It adds the ability
 * to hold the SQL <code>TIMESTAMP</code> nanos value and provides formatting and
 * parsing operations to support the JDBC escape syntax for timestamp values.
 *
 * <P><B>Note:</B> This type is a composite of a <code>java.util.Date</code> and a
 * separate nanoseconds value. Only integral seconds are stored in the
 * <code>java.util.Date</code> component. The fractional seconds - the nanos - are
 * separate.  The <code>Timestamp.equals(Object)</code> method never returns 
 * <code>true</code> when passed a value of type <code>java.util.Date</code>
 * because the nanos component of a date is unknown.
 * As a result, the <code>Timestamp.equals(Object)</code>
 * method is not symmetric with respect to the
 * <code>java.util.Date.equals(Object)</code>
 * method.  Also, the <code>hashcode</code> method uses the underlying 
 * <code>java.util.Data</code> 
 * implementation and therefore does not include nanos in its computation.  
 * <P>
 * Due to the differences between the <code>Timestamp</code> class
 * and the <code>java.util.Date</code>
 * class mentioned above, it is recommended that code not view
 * <code>Timestamp</code> values generically as an instance of
 * <code>java.util.Date</code>.  The
 * inheritance relationship between <code>Timestamp</code>
 * and <code>java.util.Date</code> really 
 * denotes implementation inheritance, and not type inheritance.  
 */
public class Timestamp extends java.util.Date {

    /**
     * Constructs a <code>Timestamp</code> object initialized
     * with the given values.
     *
     * @param year the year minus 1900
     * @param month 0 to 11 
     * @param date 1 to 31
     * @param hour 0 to 23
     * @param minute 0 to 59
     * @param second 0 to 59
     * @param nano 0 to 999,999,999
     * @deprecated instead use the constructor <code>Timestamp(long millis)</code>
     * @exception IllegalArgumentException if the nano argument is out of bounds
     */
    public Timestamp(int year, int month, int date, 
		     int hour, int minute, int second, int nano) {
	super(year, month, date, hour, minute, second);
	if (nano > 999999999 || nano < 0) {
	    throw new IllegalArgumentException("nanos > 999999999 or < 0");
	}
	nanos = nano;
    }

    /**
     * Constructs a <code>Timestamp</code> object 
     * using a milliseconds time value. The
     * integral seconds are stored in the underlying date value; the
     * fractional seconds are stored in the <code>nanos</code> field of
     * the <code>Timestamp</code> object.
     *
     * @param time milliseconds since January 1, 1970, 00:00:00 GMT.
     *        A negative number is the number of milliseconds before
     *         January 1, 1970, 00:00:00 GMT.
     * @see java.util.Calendar for more information
     */
    public Timestamp(long time) {
	super((time/1000)*1000);
	nanos = (int)((time%1000) * 1000000);
	if (nanos < 0) {
	    nanos = 1000000000 + nanos;	    
	    super.setTime(((time/1000)-1)*1000);
	}
    }

    /**
     * Sets this <code>Timestamp</code> object to represent a point in time that is 
     * <tt>time</tt> milliseconds after January 1, 1970 00:00:00 GMT. 
     *
     * @param time   the number of milliseconds.
     * @see #getTime
     * @see #Timestamp(long time)
     * @see java.util.Calendar for more information
     */
    public void setTime(long time) {
	super.setTime((time/1000)*1000);
	nanos = (int)((time%1000) * 1000000);
	if (nanos < 0) {
	    nanos = 1000000000 + nanos;	    
	    super.setTime(((time/1000)-1)*1000);
	}
    }

    /**
     * Returns the number of milliseconds since January 1, 1970, 00:00:00 GMT
     * represented by this <code>Timestamp</code> object.
     *
     * @return  the number of milliseconds since January 1, 1970, 00:00:00 GMT
     *          represented by this date.
     * @see #setTime
     */
    public long getTime() {
        long time = super.getTime();
        return (time + (nanos / 1000000));
    }
            

    /**
     * @serial
     */
    private int nanos;

    /**
     * Converts a <code>String</code> object in JDBC timestamp escape format to a
     * <code>Timestamp</code> value.
     *
     * @param s timestamp in format <code>yyyy-mm-dd hh:mm:ss.fffffffff</code>
     * @return corresponding <code>Timestamp</code> value
     * @exception java.lang.IllegalArgumentException if the given argument
     * does not have the format <code>yyyy-mm-dd hh:mm:ss.fffffffff</code>
     */
    public static Timestamp valueOf(String s) {
	String date_s;
	String time_s;
	String nanos_s;
	int year;
	int month;
	int day;
	int hour;
	int minute;
	int second;
	int a_nanos = 0;
	int firstDash;
	int secondDash;
	int dividingSpace;
	int firstColon = 0;
	int secondColon = 0;
	int period = 0;
	String formatError = "Timestamp format must be yyyy-mm-dd hh:mm:ss.fffffffff";
	String zeros = "000000000";

	if (s == null) throw new java.lang.IllegalArgumentException("null string");

	// Split the string into date and time components
	s = s.trim();
	dividingSpace = s.indexOf(' ');
	if (dividingSpace > 0) {
	    date_s = s.substring(0,dividingSpace);
	    time_s = s.substring(dividingSpace+1);
	} else {
	    throw new java.lang.IllegalArgumentException(formatError);
	}


	// Parse the date
	firstDash = date_s.indexOf('-');
	secondDash = date_s.indexOf('-', firstDash+1);

	// Parse the time
	if (time_s == null) 
	    throw new java.lang.IllegalArgumentException(formatError);
	firstColon = time_s.indexOf(':');
	secondColon = time_s.indexOf(':', firstColon+1);
	period = time_s.indexOf('.', secondColon+1);

	// Convert the date
	if ((firstDash > 0) & (secondDash > 0) & 
	    (secondDash < date_s.length()-1)) {
	    year = Integer.parseInt(date_s.substring(0, firstDash)) - 1900;
	    month = 
		Integer.parseInt(date_s.substring
				 (firstDash+1, secondDash)) - 1;
	    day = Integer.parseInt(date_s.substring(secondDash+1));
	} else {		
	    throw new java.lang.IllegalArgumentException(formatError);
	}

	// Convert the time; default missing nanos
	if ((firstColon > 0) & (secondColon > 0) & 
	    (secondColon < time_s.length()-1)) {
	    hour = Integer.parseInt(time_s.substring(0, firstColon));
	    minute = 
		Integer.parseInt(time_s.substring(firstColon+1, secondColon));
	    if ((period > 0) & (period < time_s.length()-1)) {
		second = 
		    Integer.parseInt(time_s.substring(secondColon+1, period));
		nanos_s = time_s.substring(period+1);
		if (nanos_s.length() > 9) 
		    throw new java.lang.IllegalArgumentException(formatError);
		if (!Character.isDigit(nanos_s.charAt(0)))
		    throw new java.lang.IllegalArgumentException(formatError);
		nanos_s = nanos_s + zeros.substring(0,9-nanos_s.length());
		a_nanos = Integer.parseInt(nanos_s);
	    } else if (period > 0) {
		throw new java.lang.IllegalArgumentException(formatError);
	    } else {
		second = Integer.parseInt(time_s.substring(secondColon+1));
	    }
	} else {
	    throw new java.lang.IllegalArgumentException();
	}

	return new Timestamp(year, month, day, hour, minute, second, a_nanos);
    }

    /**
     * Formats a timestamp in JDBC timestamp escape format.
     *         <code>yyyy-mm-dd hh:mm:ss.fffffffff</code>,
     * where <code>ffffffffff</code> indicates nanoseconds.
     * <P>
     * NOTE: To specify a timestamp for the class 
     * <code>java.text.SimpleDateFormat</code>, use "yyyy.MM.dd" rather than
     * "yyyy-mm-dd". In the context of <code>java.text.SimpleDateFormat</code>,
     * "mm" indicates minutes rather than the month. Note that 
     * <code>java.text.SimpleDateFormat</code> does not allow for the
     * nanoseconds component of a <code>Timestamp</code> object.
     * For Example:
     * <PRE>
     *
     * Format Pattern				Result
     * --------------				------
     * "yyyy.MM.dd G 'at' hh:mm:ss z"	-->	2002.07.10 AD at 15:08:56 PDT
     *
     * </PRE>
     * @return a <code>String</code> object in
     *           <code>yyyy-mm-dd hh:mm:ss.fffffffff</code> format
     */
    public String toString () {

	int year = super.getYear() + 1900;
	int month = super.getMonth() + 1;
	int day = super.getDate();
	int hour = super.getHours();
	int minute = super.getMinutes();
	int second = super.getSeconds();
	String yearString;
	String monthString;
	String dayString;
	String hourString;
	String minuteString;
	String secondString;
	String nanosString;
	String zeros = "000000000";