/*
* This file is part of JGAP.
*
* JGAP offers a dual license model containing the LGPL as well as the MPL.
*
* For licensing information please see the file license.txt included with JGAP
* or have a look at the top of class org.jgap.Chromosome which representatively
* includes the JGAP license policy applicable for any file delivered with JGAP.
*/
package org.jgap;
import java.io.*;
import java.lang.reflect.*;
import java.util.*;
import org.jgap.impl.*;
import org.jgap.util.*;
/**
* Base class for any implementation of interface IChromosome.
*
* @author Klaus Meffert
* @since 3.0
*/
public abstract class BaseChromosome
implements IChromosome, IInitializer, IPersistentRepresentation, IBusinessKey {
/** String containing the CVS revision. Read out via reflection!*/
private final static String CVS_REVISION = "$Revision: 1.15 $";
/**
* This field separates gene class name from the gene persistent representation
* string. '*' does not work properly with URLEncoder!
*/
public final static String GENE_DELIMITER = "#";
/**
* Represents the heading delimiter that is used to separate genes in the
* persistent representation of Chromosome instances.
*/
public final static String GENE_DELIMITER_HEADING = "<";
/**
* Represents the closing delimiter that is used to separate genes in the
* persistent representation of Chromosome instances.
*/
public final static String GENE_DELIMITER_CLOSING = ">";
/**
* Separates chromosome-related information.
*/
public final static String CHROM_DELIMITER = "#";
/**
* The configuration object to use
*/
private Configuration m_configuration;
/**
* The array of Genes contained in this Chromosome.
*/
private Gene[] m_genes;
private int m_age;
private int m_operatedOn;
/**
* Unique ID of the chromosome that allows to distinct it from other
* chromosomes. In the best case, this ID is unique worldwide.
*/
private String m_uniqueID;
/**
* In case mutation, crossing over etc. happened, this sequence gives evidence
* about the parent(s) of the current chromosome.
*/
private Map m_uniqueIDTemplates;
/**
* The only constructor in this class. Sets the immutable configuration.
*
* @param a_configuration the configuration to set
* @throws InvalidConfigurationException if configuration is null
*
* @author Klaus Meffert
* @since 3.0
*/
public BaseChromosome(Configuration a_configuration)
throws InvalidConfigurationException {
if (a_configuration == null) {
throw new InvalidConfigurationException(
"Configuration to be set must not"
+ " be null!");
}
m_configuration = a_configuration;
if (m_configuration.isUniqueKeysActive()) {
m_uniqueIDTemplates = new HashMap();
IJGAPFactory factory = m_configuration.getJGAPFactory();
if (JGAPFactory.class.isAssignableFrom(factory.getClass())) {
m_uniqueID = ( (JGAPFactory) (m_configuration.getJGAPFactory())).
getUniqueKey(getClass().getName());
}
}
}
/**
* @return unique ID of the chromosome, which allows to distinct this instance
* from others, in the best case worldwide
*
* @author Klaus Meffert
* @since 3.5
*/
public String getUniqueID() {
return m_uniqueID;
}
/**
* A template is a chromosome that is the logical predecessor of the current
* chromosome. A template can occur in mutation or crossing over. In the
* latter case can be at least two template chromosomes. This is why in this
* setter method the parameter a_index exists.
*
* @param a_templateID the unique ID of the template
* @param a_index the index of the template, e.g. in crossing over for the
* second candidate chromosome this is 2
*
* @author Klaus Meffert
* @since 3.5
*/
public void setUniqueIDTemplate(String a_templateID, int a_index) {
m_uniqueIDTemplates.put(a_index, a_templateID);
}
/**
* @param a_index the index of the template to retrieve the key for
* @return String
*
* @author Klaus Meffert
* @since 3.5
*/
public String getUniqueIDTemplate(int a_index) {
return m_uniqueIDTemplates.get(a_index);
}
/**
* @return the configuration used
*
* @author Klaus Meffert
* @since 3.0
*/
public Configuration getConfiguration() {
return m_configuration;
}
/**
* Creates and returns a copy of this object.
*
* @return a clone of this instance
* @throws IllegalStateException instead of CloneNotSupportedException
*
* @author Klaus Meffert
* @since 3.0
*/
public abstract Object clone();
/**
* Increases the number of evolutionary rounds of chromosome in which it has
* not been changed by one.
*
* @author Klaus Meffert
* @since 3.2
*/
public void increaseAge() {
m_age++;
}
/**
* Reset age of chromosome because it has been changed.
*
* @author Klaus Meffert
* @since 3.2
*/
public void resetAge() {
m_age = 0;
}
/**
* @return 0: Chromosome newly created in this generation. This means it
* does not need being crossed over with another newly created one
*
* @author Klaus Meffert
* @since 3.2
*/
public int getAge() {
return m_age;
}
/**
* @param a_age set the age of the chromosome, see BestChromosomesSelector
* for a use-case
*
* @author Klaus Meffert
* @since 3.3.3
*/
public void setAge(int a_age) {
m_age = a_age;
}
/**
* Increase information of number of genetic operations performed on
* chromosome in current evolution round.
*
* @author Klaus Meffert
* @since 3.2
*/
public void increaseOperatedOn() {
m_operatedOn++;
}
/**
* Resets the information of how many genetic operators have been performed
* on the chromosome in the current round of evolution.
*
* @author Klaus Meffert
* @since 3.2
*
*/
public void resetOperatedOn() {
m_operatedOn = 0;
}
/**
* @return number of genetic operations performed on chromosome in current
* evolution round
*
* @author Klaus Meffert
* @since 3.2
*/
public int operatedOn() {
return m_operatedOn;
}
/**
* Retrieves the set of genes that make up this Chromosome. This method
* exists primarily for the benefit of GeneticOperators that require the
* ability to manipulate Chromosomes at a low level.
*
* @return an array of the Genes contained within this Chromosome
*
* @author Neil Rotstan
* @since 1.0
*/
public synchronized Gene[] getGenes() {
return m_genes;
}
/**
* Sets the genes for the chromosome.
*
* @param a_genes the genes to set for the chromosome
*
* @throws InvalidConfigurationException in case constraint checker is
* provided
*
* @author Klaus Meffert
* @since 3.2 (previously in class Chromosome)
*/
public void setGenes(Gene[] a_genes)
throws InvalidConfigurationException {
m_genes = a_genes;
}
/**
* Returns the Gene at the given index (locus) within the Chromosome. The
* first gene is at index zero and the last gene is at the index equal to
* the size of this Chromosome - 1.
*
* @param a_desiredLocus index of the gene value to be returned
* @return Gene at the given index
*
* @author Neil Rotstan
* @since 1.0
*/
public synchronized Gene getGene(int a_desiredLocus) {
return m_genes[a_desiredLocus];
}
public void setGene(int a_index, Gene a_gene) {
m_genes[a_index] = a_gene;
}
/**
* Returns the size of this Chromosome (the number of genes it contains).
* A Chromosome's size is constant and will not change, until setGenes(...)
* is used.
*
* @return number of genes contained within this Chromosome instance
*
* @author Neil Rotstan
* @author Klaus Meffert
* @since 1.0
*/
public int size() {
if (m_genes == null) {
// only possible when using default constructor
return 0;
}
else {
return m_genes.length;
}
}
/**
* Returns a persistent representation of this chromosome, see interface Gene
* for description. Similar to CompositeGene's routine. But does not include
* all information of the chromosome (yet).
*
* @return string representation of this Chromosome's relevant parts of its
* current state
* @throws UnsupportedOperationException
*
* @author Klaus Meffert
* @since 3.2
*/
public String getPersistentRepresentation() {
StringBuffer b = new StringBuffer();
// Persist the chromosome's fitness value.
// ---------------------------------------
b.append(getFitnessValueDirectly());
b.append(CHROM_DELIMITER);
// Persist the genes.
// ------------------
b.append(size());
b.append(CHROM_DELIMITER);
getGenesPersistentRepresentation(b);
return b.toString();
}
/**
* @return the persistent representation of the chromosome by considering
* its genes.
*
* @author Klaus Meffert
*/
public StringBuffer getGenesPersistentRepresentation() {
StringBuffer b = new StringBuffer();
getGenesPersistentRepresentation(b);
return b;
}
/**
* @return business key of the chromosome
*
* @author Klaus Meffert
* @since 3.2
*/
public String getBusinessKey() {
return getGenesPersistentRepresentation().toString();
}
/**
* Retrieves the persistent representation of the chromosome by considering
* its genes.
*
* @param a_buffer the variable to store the persistent representation in
*
* @author Klaus Meffert
*/
public void getGenesPersistentRepresentation(StringBuffer a_buffer) {
Gene gene;
int size = size();
for (int i = 0; i < size; i++) {
gene = getGene(i);
a_buffer.append(GENE_DELIMITER_HEADING);
a_buffer.append(encode(gene.getClass().getName()
+ GENE_DELIMITER
+ gene.getPersistentRepresentation()));
a_buffer.append(GENE_DELIMITER_CLOSING);
}
}
protected String encode(String a_string) {
return StringKit.encode(a_string);
}
protected String decode(String a_string) throws UnsupportedEncodingException {
return StringKit.decode(a_string);
}
/**
* Counterpart of getPersistentRepresentation.
*
* @param a_representation the string representation retrieved from a prior
* call to the getPersistentRepresentation() method
*
* @throws UnsupportedRepresentationException
*
* @author Klaus Meffert
* @since 3.2
*/
public void setValueFromPersistentRepresentation(String a_representation)
throws UnsupportedRepresentationException {
if (a_representation != null) {
try {
List r = split(a_representation);
String g;
// Obtain fitness value.
// ---------------------
g = decode( (String) r.get(0));
setFitnessValue(Double.parseDouble(g));
r.remove(0);/**@todo we can do this faster!*/
// Obtain number of genes.
// -----------------------
g = decode( (String) r.get(0));
int count = Integer.parseInt(g);
setGenes(new Gene[count]);
r.remove(0);/**@todo we can do this faster!*/
// Obtain the genes.
// -----------------
Iterator iter = r.iterator();
StringTokenizer st;
String clas;
String representation;
Gene gene;
int index = 0;
while (iter.hasNext()) {
g = decode( (String) iter.next());
st = new StringTokenizer(g, GENE_DELIMITER);
if (st.countTokens() != 2)
throw new UnsupportedRepresentationException("In " + g + ", " +
"expecting two tokens, separated by " + GENE_DELIMITER);
clas = st.nextToken();
representation = st.nextToken();
gene = createGene(clas, representation);
setGene(index++, gene);
}
}
catch (Exception ex) {
throw new UnsupportedRepresentationException(ex.toString());
}
}
}
/**
* Creates a new Gene instance.
* Taken from CompositeGene.
*
* @param a_geneClassName name of the gene class
* @param a_persistentRepresentation persistent representation of the gene to
* create (could be obtained via getPersistentRepresentation)
*
* @return newly created gene
* @throws Exception
*
* @author Klaus Meffert
* @since 3.2
*/
protected Gene createGene(String a_geneClassName,
String a_persistentRepresentation)
throws Exception {
Class geneClass = Class.forName(a_geneClassName);
Constructor constr = geneClass.getConstructor(new Class[] {Configuration.class});
Gene gene = (Gene) constr.newInstance(new Object[] {getConfiguration()});
gene.setValueFromPersistentRepresentation(a_persistentRepresentation);
return gene;
}
/**
* Splits the input a_string into individual gene representations.
* Taken and adapted from CompositeGene.
*
* @param a_string the string to split
* @return the elements of the returned array are the persistent
* representation strings of the chromosome's components
* @throws UnsupportedRepresentationException
*
* @author Klaus Meffert
* @since 3.2
*/
protected static final List split(String a_string)
throws UnsupportedRepresentationException {
List a = Collections.synchronizedList(new ArrayList());
// Header data.
// ------------
int index = 0;
StringTokenizer st0 = new StringTokenizer
(a_string, CHROM_DELIMITER, false);
if (!st0.hasMoreTokens()) {
throw new UnsupportedRepresentationException("Fitness value expected!");
}
String fitnessS = st0.nextToken();
a.add(fitnessS);
index += fitnessS.length();
if (!st0.hasMoreTokens()) {
throw new UnsupportedRepresentationException("Number of genes expected!");
}
String numGenes = st0.nextToken();
a.add(numGenes);
index += numGenes.length();
index += 2; //2 one-character delimiters
if (!st0.hasMoreTokens()) {
throw new UnsupportedRepresentationException("Gene data missing!");
}
// Remove previously parsed content.
// ---------------------------------
a_string = a_string.substring(index);
// Gene data.
// ----------
StringTokenizer st = new StringTokenizer
(a_string, GENE_DELIMITER_HEADING + GENE_DELIMITER_CLOSING, true);
while (st.hasMoreTokens()) {
if (!st.nextToken().equals(GENE_DELIMITER_HEADING)) {
throw new UnsupportedRepresentationException(a_string + " no open tag");
}
String n = st.nextToken();
if (n.equals(GENE_DELIMITER_CLOSING)) {
a.add(""); /* Empty token */
}
else {
a.add(n);
if (!st.nextToken().equals(GENE_DELIMITER_CLOSING)) {
throw new UnsupportedRepresentationException
(a_string + " no close tag");
}
}
}
return a;
}
}
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