org.jcamp.units.DerivedUnit Maven / Gradle / Ivy
package org.jcamp.units;
/**
* unit that is derived from base units.
*
* @author Thomas Weber
*/
public final class DerivedUnit
extends Unit {
/** for serialization. */
private static final long serialVersionUID = -6912254468800545391L;
String quantity = null;
String name = null;
String symbol = null;
UnitFactor[] factors;
public DerivedUnit() {
super("");
this.factors = new UnitFactor[0];
this.name = "";
this.quantity = "";
this.symbol = "";
}
public DerivedUnit(BaseUnit[] baseUnits, int[] powers, String quantity, String name, String symbol) {
this(makeFactors(baseUnits, powers), makeID(quantity, name, symbol), name);
this.name = name;
this.symbol = symbol;
this.quantity = quantity;
}
private DerivedUnit(UnitFactor[] factors, String identifier) {
super(identifier);
this.factors = factors;
}
private DerivedUnit(UnitFactor[] factors, String identifier, String alias) {
super(identifier, alias);
this.factors = factors;
}
/**
* constructor for dimensionless units
*/
public DerivedUnit(String quantity, String name, String symbol) {
super(makeID(quantity, name, symbol), name);
this.factors = new UnitFactor[0];
this.quantity = quantity;
this.name = name;
this.symbol = symbol;
}
/**
* cloning.
*
* @return java.lang.Object
*/
@Override
public Object clone() {
DerivedUnit unit = (DerivedUnit) super.clone();
for (int i = 0; i < factors.length; i++)
unit.factors[i] = (UnitFactor) this.factors[i].clone();
return unit;
}
/**
* convert value from unit thatUnit to this unit.
* @param value double
* @param thatUnit Unit
* @return double
*/
@Override
public double convertFrom(double value, Unit thatUnit) throws UnitException {
if (isConvertibleTo(thatUnit)) {
if (thatUnit instanceof DerivedUnit)
return value;
else
return thatUnit.convertTo(value, this);
} else
throw new UnitException("units not convertible");
}
/**
* convert value to unit thatUnit from this unit.
* @param value double
* @param thatUnit Unit
* @return double
*/
@Override
public double convertTo(double value, Unit thatUnit) throws UnitException {
if (isConvertibleTo(thatUnit)) {
if (thatUnit instanceof DerivedUnit)
return value;
else
return thatUnit.convertFrom(value, this);
} else
throw new UnitException("units not convertible");
}
/**
* gets unit name.
* @return String
*/
@Override
public String getName() {
return name;
}
/**
* gets quantity.
* @return String
*/
@Override
public java.lang.String getQuantity() {
return quantity;
}
/**
* gets scale factor.
* @return double
*/
@Override
public final double getScaleFactor() {
return 1.0;
}
/**
* gets symbol.
* @return String
*/
@Override
public String getSymbol() {
return symbol;
}
/**
* checks if unit is convertible to unit thatUnit.
* @param thatUnit Unit
* @return boolean
*/
@Override
public boolean isConvertibleTo(Unit thatUnit) {
if (thatUnit instanceof DerivedUnit) {
DerivedUnit thatDerived = (DerivedUnit) thatUnit;
if (factors.length == thatDerived.factors.length) {
for (int i = 0; i < factors.length; i++) {
if (!factors[i].equals(thatDerived.factors[i]))
return false;
}
return true;
}
return false;
} else if (thatUnit instanceof BaseUnit)
return false;
else
return thatUnit.isConvertibleTo(this);
}
/**
* make unit factors.
* @param baseUnits BaseUnit[]
* @param powers int[]
* @return UnitFactor[]
*/
private static UnitFactor[] makeFactors(BaseUnit[] baseUnits, int[] powers) {
int n = baseUnits.length;
UnitFactor[] factors = new UnitFactor[n];
for (int i = 0; i < n; i++) {
factors[i] = new UnitFactor(baseUnits[i], powers[i]);
}
return factors;
}
/**
* make key from name of symbol.
* @param quantity java.lang.String
* @param name java.lang.String
* @param symbol java.lang.String
* @return String
*/
private static String makeID(String quantity, String name, String symbol) {
if (symbol != null && symbol.length() > 0)
return symbol;
if (name != null && name.length() > 0)
return name;
return quantity;
}
}