/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2001-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library 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
* Lesser General Public License for more details.
*
* This package contains documentation from OpenGIS specifications.
* OpenGIS consortium's work is fully acknowledged here.
*/
package org.geotools.referencing.datum;
import java.util.Collections;
import java.util.Date;
import java.util.Map;
import org.opengis.util.InternationalString;
import org.opengis.referencing.datum.TemporalDatum;
import org.geotools.referencing.AbstractIdentifiedObject;
import org.geotools.resources.i18n.VocabularyKeys;
/**
* A temporal datum defines the origin of a temporal coordinate reference system.
*
*
* @source $URL$
* @version $Id$
* @author Martin Desruisseaux (IRD)
*
* @since 2.1
*/
public class DefaultTemporalDatum extends AbstractDatum implements TemporalDatum {
/**
* Serial number for interoperability with different versions.
*/
private static final long serialVersionUID = 3357241732140076884L;
/**
* Datum for time measured since January 1st, 4713 BC at 12:00 UTC.
*
* @see org.geotools.referencing.crs.DefaultTemporalCRS#JULIAN
*
* @since 2.5
*/
public static final DefaultTemporalDatum JULIAN = new DefaultTemporalDatum(
name(VocabularyKeys.JULIAN), new Date(-2440588 * (24*60*60*1000L) + (12*60*60*1000L)));
/**
* Datum for time measured since November 17, 1858 at 00:00 UTC.
* A <cite>Modified Julian day</cite> (MJD) is defined relative to <cite>Julian day</cite>
* (JD) as {@code MJD = JD − 2400000.5}.
*
* @see org.geotools.referencing.crs.DefaultTemporalCRS#MODIFIED_JULIAN
*
* @since 2.5
*/
public static final DefaultTemporalDatum MODIFIED_JULIAN = new DefaultTemporalDatum(
name(VocabularyKeys.MODIFIED_JULIAN), new Date(-40587 * (24*60*60*1000L)));
/**
* Datum for time measured since May 24, 1968 at 00:00 UTC. This epoch was introduced by NASA
* for the space program. A <cite>Truncated Julian day</cite> (TJD) is defined relative to
* <cite>Julian day</cite> (JD) as {@code TJD = JD − 2440000.5}.
*
* @see org.geotools.referencing.crs.DefaultTemporalCRS#TRUNCATED_JULIAN
*
* @since 2.5
*/
public static final DefaultTemporalDatum TRUNCATED_JULIAN = new DefaultTemporalDatum(
name(VocabularyKeys.TRUNCATED_JULIAN), new Date(-587 * (24*60*60*1000L)));
/**
* Datum for time measured since December 31, 1899 at 12:00 UTC.
* A <cite>Dublin Julian day</cite> (DJD) is defined relative to <cite>Julian day</cite> (JD)
* as {@code DJD = JD − 2415020}.
*
* @see org.geotools.referencing.crs.DefaultTemporalCRS#DUBLIN_JULIAN
*
* @since 2.5
*/
public static final DefaultTemporalDatum DUBLIN_JULIAN = new DefaultTemporalDatum(
name(VocabularyKeys.DUBLIN_JULIAN), new Date(-25568 * (24*60*60*1000L) + (12*60*60*1000L)));
/**
* Default datum for time measured since January 1st, 1970 at 00:00 UTC.
*
* @see org.geotools.referencing.crs.DefaultTemporalCRS#UNIX
* @see org.geotools.referencing.crs.DefaultTemporalCRS#JAVA
*/
public static final DefaultTemporalDatum UNIX = new DefaultTemporalDatum(
"UNIX", new Date(0));
/**
* The date and time origin of this temporal datum.
*/
private final long origin;
/**
* Constructs a new datum with the same values than the specified one.
* This copy constructor provides a way to wrap an arbitrary implementation into a
* Geotools one or a user-defined one (as a subclass), usually in order to leverage
* some implementation-specific API. This constructor performs a shallow copy,
* i.e. the properties are not cloned.
*
* @since 2.2
*/
public DefaultTemporalDatum(final TemporalDatum datum) {
super(datum);
origin = datum.getOrigin().getTime();
}
/**
* Constructs a temporal datum from a name.
*
* @param name The datum name.
* @param origin The date and time origin of this temporal datum.
*/
public DefaultTemporalDatum(final String name, final Date origin) {
this(Collections.singletonMap(NAME_KEY, name), origin);
}
/**
* Constructs a temporal datum from a set of properties. The properties map is given
* unchanged to the {@linkplain AbstractDatum#AbstractDatum(Map) super-class constructor}.
*
* @param properties Set of properties. Should contains at least {@code "name"}.
* @param origin The date and time origin of this temporal datum.
*/
public DefaultTemporalDatum(final Map<String,?> properties, final Date origin) {
super(properties);
ensureNonNull("origin", origin);
this.origin = origin.getTime();
}
/**
* The date and time origin of this temporal datum.
*
* @return The date and time origin of this temporal datum.
*/
public Date getOrigin() {
return new Date(origin);
}
/**
* Description of the point or points used to anchor the datum to the Earth.
*/
@Override
public InternationalString getAnchorPoint() {
return super.getAnchorPoint();
}
/**
* The time after which this datum definition is valid.
*/
@Override
public Date getRealizationEpoch() {
return super.getRealizationEpoch();
}
/**
* Compare this temporal datum with the specified object for equality.
*
* @param object The object to compare to {@code this}.
* @param compareMetadata {@code true} for performing a strict comparaison, or
* {@code false} for comparing only properties relevant to transformations.
* @return {@code true} if both objects are equal.
*/
@Override
public boolean equals(final AbstractIdentifiedObject object, final boolean compareMetadata) {
if (object == this) {
return true; // Slight optimization.
}
if (super.equals(object, compareMetadata)) {
final DefaultTemporalDatum that = (DefaultTemporalDatum) object;
return this.origin == that.origin;
}
return false;
}
/**
* Returns a hash value for this temporal datum. {@linkplain #getName Name},
* {@linkplain #getRemarks remarks} and the like are not taken in account. In
* other words, two temporal datums will return the same hash value if they
* are equal in the sense of
* <code>{@link #equals equals}(AbstractIdentifiedObject, <strong>false</strong>)</code>.
*
* @return The hash code value. This value doesn't need to be the same
* in past or future versions of this class.
*/
@Override
public int hashCode() {
return super.hashCode() ^ (int)origin ^ (int)(origin >>> 32);
}
}