/*
* Copyright 1998-2014 University Corporation for Atmospheric Research/Unidata
*
* Portions of this software were developed by the Unidata Program at the
* University Corporation for Atmospheric Research.
*
* Access and use of this software shall impose the following obligations
* and understandings on the user. The user is granted the right, without
* any fee or cost, to use, copy, modify, alter, enhance and distribute
* this software, and any derivative works thereof, and its supporting
* documentation for any purpose whatsoever, provided that this entire
* notice appears in all copies of the software, derivative works and
* supporting documentation. Further, UCAR requests that the user credit
* UCAR/Unidata in any publications that result from the use of this
* software or in any product that includes this software. The names UCAR
* and/or Unidata, however, may not be used in any advertising or publicity
* to endorse or promote any products or commercial entity unless specific
* written permission is obtained from UCAR/Unidata. The user also
* understands that UCAR/Unidata is not obligated to provide the user with
* any support, consulting, training or assistance of any kind with regard
* to the use, operation and performance of this software nor to provide
* the user with any updates, revisions, new versions or "bug fixes."
*
* THIS SOFTWARE IS PROVIDED BY UCAR/UNIDATA "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL UCAR/UNIDATA BE LIABLE FOR ANY SPECIAL,
* INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package ucar.units;
import net.jcip.annotations.Immutable;
import java.util.SortedMap;
import java.util.TreeMap;
/**
* Provides support for unknown base units. This can be used, for example, to
* accomodate an unknown unit (e.g. "foo"). Values in such a unit will only be
* convertible with units derived from "foo" (e.g. "20 foo").
*
* @author Steven R. Emmerson
*/
@Immutable
public final class UnknownUnit extends BaseUnit {
private static final long serialVersionUID = 1L;
/**
* The name-to-unit map.
*
* @serial
*/
private static final SortedMap<String, UnknownUnit> map = new TreeMap<>();
/**
* Constructs from a name.
*
* @param name The name of the unit.
*/
private UnknownUnit(final String name) throws NameException {
super(UnitName.newUnitName(name, null, name), BaseQuantity.UNKNOWN);
}
/**
* Factory method for constructing an unknown unit from a name.
*
* @param name The name of the unit.
* @return The unknown unit.
* @throws NameException <code>name == null</code>.
*/
public static UnknownUnit create(String name) throws NameException {
UnknownUnit unit;
name = name.toLowerCase();
synchronized (map) {
unit = map.get(name);
if (unit == null) {
unit = new UnknownUnit(name);
map.put(unit.getName(), unit);
map.put(unit.getPlural(), unit);
}
}
return unit;
}
/*
* From Unit:
*/
/**
* Indicates if this unit is semantically identical to an object.
*
* @param object The object.
* @return <code>true</code> if and only if this instance is semantically
* identical to the object.
*/
@Override
public boolean equals(final Object object) {
if (this == object) {
return true;
}
if (!(object instanceof UnknownUnit)) {
return false;
}
final UnknownUnit that = (UnknownUnit) object;
return getName().equalsIgnoreCase(that.getName());
}
/**
* Returns the hash code of this instance.
*
* @return The hash code of this instance.
*/
@Override
public int hashCode() {
return getName().toLowerCase().hashCode();
}
/**
* Indicates if this unit is dimensionless. An unknown unit is never
* dimensionless.
*
* @return <code>false</code> always.
*/
@Override
public boolean isDimensionless() {
return false;
}
}