timestamp.java

俄罗斯高人Mamaich的Pocket gcc编译器（运行在PocketPC上）的全部源代码。

/* Time.java -- Wrapper around java.util.Date
   Copyright (C) 1999, 2000, 2003 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
 
GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */


package java.sql;

import java.text.SimpleDateFormat;

/**
 * This class is a wrapper around java.util.Date to allow the JDBC
 * driver to identify the value as a SQL Timestamp.  Note that this
 * class also adds an additional field for nano-seconds, and so 
 * is not completely identical to <code>java.util.Date</code> as
 * the <code>java.sql.Date</code> and <code>java.sql.Time</code>
 * classes are.
 *
 * @author Aaron M. Renn ([e-mail])
 */
public class Timestamp extends java.util.Date
{
  static final long serialVersionUID = 2745179027874758501L;

  /**
   * Used for parsing and formatting this date.
   */
  // Millisecond will have to be close enough for now.
  private static SimpleDateFormat parse_sdf = 
    new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSS");

  private static SimpleDateFormat format_sdf =
    new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

  /**
    * The nanosecond value for this object
    */
  private int nanos;

  /**
   * This method returns a new instance of this class by parsing a
   * date in JDBC format into a Java date.
   *
   * @param str The string to parse.
   * @return The resulting <code>java.sql.Timestamp</code> value. 
   */
  public static Timestamp valueOf(String str)
  {
    try
      {
	Date d = (Date) parse_sdf.parseObject(str);
	return new Timestamp(d.getTime());
      }
    catch (Exception e)
      {
	return null;
      }
  }

  /**
   * This method initializes a new instance of this class with the
   * specified year, month, and day.
   *
   * @param year The year for this Timestamp (year - 1900)
   * @param month The month for this Timestamp (0-11)
   * @param day The day for this Timestamp (1-31)
   * @param hour The hour for this Timestamp (0-23)
   * @param minute The minute for this Timestamp (0-59)
   * @param second The second for this Timestamp (0-59)
   * @param nanos The nanosecond value for this Timestamp (0 to 999,999,9999)
   * @deprecated
   */
  public Timestamp(int year, int month, int day, int hour, int minute, 
    int second, int nanos)
  {
    super(year, month, day, hour, minute, second);
    this.nanos = nanos;
  }

  /**
   * This method initializes a new instance of this class with the
   * specified time value representing the number of seconds since 
   * Jan 1, 1970 at 12:00 midnight GMT.
   *
   * @param time The time value to intialize this <code>Time</code> to.
   */
  public Timestamp(long date)
  {
    super(date);
  }

  /**
   * This method returns this date in JDBC format.
   *
   * @return This date as a string.
   */
  public String toString()
  {
    return format_sdf.format(this) + "." + getNanos();
  }

  /**
    * This method returns the nanosecond value for this object.
    * @return The nanosecond value for this object.
    */
  public int getNanos()
  {
    return nanos;
  }

  /**
   * This method sets the nanosecond value for this object.
   *
   * @param nanos The nanosecond value for this object.
   */
  public void setNanos(int nanos)
  {
    this.nanos = nanos;
  }

  /**
   * This methods tests whether this object is earlier than the specified
   * object.
   *
   * @param ts The other <code>Timestamp</code> to test against.
   * @return <code>true</code> if this object is earlier than the other object,
   *         <code>false</code> otherwise.
   */
  public boolean before(Timestamp ts)
  {
    if (ts.getTime() > getTime())
      return true;

    if (ts.getNanos() > getNanos())
      return true;

    return false;
  }

  /**
   * This methods tests whether this object is later than the specified
   * object.
   *
   * @param ts The other <code>Timestamp</code> to test against.
   *
   * @return <code>true</code> if this object is later than the other object,
   * <code>false</code> otherwise.
   */
  public boolean after(Timestamp ts)
  {
    if (ts.getTime() < getTime())
      return true;

    if (ts.getNanos() < getNanos())
      return true;

    return false;
  }

  /**
   * This method these the specified <code>Object</code> for equality
   * against this object.  This will be true if an only if the specified
   * object is an instance of <code>Timestamp</code> and has the same
   * time value fields.
   *
   * @param obj The object to test against for equality.
   *
   * @return <code>true</code> if the specified object is equal to this
   * object, <code>false</code> otherwise.
   */
  public boolean equals(Object obj)
  {
    if (obj == null)
      return false;

    if (!(obj instanceof Timestamp))
      return false;

    return equals((Timestamp) obj);
  }

  /**
   * This method tests the specified timestamp for equality against this
   * object.  This will be true if and only if the specified object is
   * not <code>null</code> and contains all the same time value fields
   * as this object.
   *
   * @param ts The <code>Timestamp</code> to test against for equality.
   *
   * @return <code>true</code> if the specified object is equal to this
   * object, <code>false</code> otherwise.
   */
  public boolean equals(Timestamp ts)
  {
    if (ts == null)
      return false;

    if (ts.getTime() != getTime())
      return false;

    if (ts.getNanos() != getNanos())
      return false;

    return true;
  }

  /**
   * Compare two Timestamp
   * @param when the other Timestamp.
   * @return 0, if the date represented
   * by obj is exactly the same as the time represented by this
   * object, a negative if this Timestamp is before the other Timestamp, and
   * a positive value otherwise.  
   * @since 1.2
   */
  public int compareTo(Timestamp ts)
  {
    int s = super.compareTo((java.util.Date) ts);
    if (s != 0)
      return s;
    // If Date components were equal, then we check the nanoseconds.
    return nanos - ts.nanos;
  }

  /**
   * Compares this Timestamp to another.  This behaves like
   * <code>compareTo(Timestamp)</code>, but it may throw a
   * <code>ClassCastException</code>
   * @param obj the other Timestamp.
   * @return 0, if the Timestamp represented
   * by obj is exactly the same as the time represented by this
   * object, a negative if this Timestamp is before the other Timestamp, and
   * a positive value otherwise.  
   * @exception ClassCastException if obj is not of type Timestamp.
   * @since 1.2
   */
  public int compareTo(Object obj)
  {
    return compareTo((Timestamp) obj);
  }
}