/**
* Clones an object by using clone handlers. If no deep cloning possible, then return the
* reference.
*
* @param a_object the object to clone
* @return the cloned object, or the object itself if no coning supported
* @throws Exception
* @author Klaus Meffert
* @since 2.6
*/
protected Object cloneObject(Object a_object) throws Exception {
if (a_object == null) {
return null;
}
// Try to clone via a registered clone handler.
// --------------------------------------------
ICloneHandler cloner =
getConfiguration().getJGAPFactory().getCloneHandlerFor(a_object, a_object.getClass());
if (cloner != null) {
return cloner.perform(a_object, null, this);
} else {
// No cloning supported, so just return the reference.
// ---------------------------------------------------
return a_object;
}
}
/**
* Returns a copy of this Chromosome. The returned instance can evolve independently of this
* instance. Note that, if possible, this method will first attempt to acquire a Chromosome
* instance from the active ChromosomePool (if any) and set its value appropriately before
* returning it. If that is not possible, then a new Chromosome instance will be constructed and
* its value set appropriately before returning.
*
* @return copy of this Chromosome
* @throws IllegalStateException instead of CloneNotSupportedException
* @author Neil Rotstan
* @author Klaus Meffert
* @since 1.0
*/
public synchronized Object clone() {
// Before doing anything, make sure that a Configuration object
// has been set on this Chromosome. If not, then throw an
// IllegalStateException.
// ------------------------------------------------------------
if (getConfiguration() == null) {
throw new IllegalStateException(
"The active Configuration object must be set on this "
+ "Chromosome prior to invocation of the clone() method.");
}
IChromosome copy = null;
// Now, first see if we can pull a Chromosome from the pool and just
// set its gene values (alleles) appropriately.
// ------------------------------------------------------------
IChromosomePool pool = getConfiguration().getChromosomePool();
if (pool != null) {
copy = pool.acquireChromosome();
if (copy != null) {
Gene[] genes = copy.getGenes();
for (int i = 0; i < size(); i++) {
genes[i].setAllele(getGene(i).getAllele());
}
}
}
try {
if (copy == null) {
// We couldn't fetch a Chromosome from the pool, so we need to create
// a new one. First we make a copy of each of the Genes. We explicity
// use the Gene at each respective gene location (locus) to create the
// new Gene that is to occupy that same locus in the new Chromosome.
// -------------------------------------------------------------------
int size = size();
if (size > 0) {
Gene[] copyOfGenes = new Gene[size];
for (int i = 0; i < copyOfGenes.length; i++) {
copyOfGenes[i] = getGene(i).newGene();
Object allele = getGene(i).getAllele();
if (allele != null) {
IJGAPFactory factory = getConfiguration().getJGAPFactory();
if (factory != null) {
ICloneHandler cloner = factory.getCloneHandlerFor(allele, allele.getClass());
if (cloner != null) {
try {
allele = cloner.perform(allele, null, this);
} catch (Exception ex) {
throw new RuntimeException(ex);
}
}
}
}
copyOfGenes[i].setAllele(allele);
}
// Now construct a new Chromosome with the copies of the genes and
// return it. Also clone the IApplicationData object later on.
// ---------------------------------------------------------------
if (getClass() == Chromosome.class) {
copy = new Chromosome(getConfiguration(), copyOfGenes);
} else {
copy = (IChromosome) getConfiguration().getSampleChromosome().clone();
copy.setGenes(copyOfGenes);
}
} else {
if (getClass() == Chromosome.class) {
copy = new Chromosome(getConfiguration());
} else {
copy = (IChromosome) getConfiguration().getSampleChromosome().clone();
}
}
}
copy.setFitnessValue(m_fitnessValue);
// Clone constraint checker.
// -------------------------
copy.setConstraintChecker(getConstraintChecker());
} catch (InvalidConfigurationException iex) {
throw new IllegalStateException(iex.getMessage());
}
// Also clone the IApplicationData object.
// ---------------------------------------
try {
copy.setApplicationData(cloneObject(getApplicationData()));
} catch (Exception ex) {
throw new IllegalStateException(ex.getMessage());
}
// Clone multi-objective object if necessary and possible.
// -------------------------------------------------------
if (m_multiObjective != null) {
if (getClass() == Chromosome.class) {
try {
((Chromosome) copy).setMultiObjectives((List) cloneObject(m_multiObjective));
} catch (Exception ex) {
throw new IllegalStateException(ex.getMessage());
}
}
}
return copy;
}