1 package net.bmahe.genetics4j.core;
2
3 import java.util.Arrays;
4 import java.util.Collection;
5
6 import org.apache.commons.lang3.Validate;
7
8 import net.bmahe.genetics4j.core.chromosomes.Chromosome;
9
10 /**
11 * Represents a genotype in an evolutionary algorithm, which is a collection of chromosomes.
12 *
13 * <p>A genotype encapsulates the complete genetic representation of an individual solution,
14 * consisting of one or more chromosomes that together define the individual's characteristics.
15 * Each chromosome may represent different aspects or components of the solution space.
16 *
17 * <p>Genotypes are immutable once created and provide type-safe access to their constituent chromosomes.
18 *
19 * @see Chromosome
20 * @see Individual
21 */
22 public class Genotype {
23
24 private final Chromosome[] chromosomes;
25
26 /**
27 * Creates a new genotype with the specified chromosomes.
28 *
29 * @param _chromosomes one or more chromosomes to include in this genotype
30 * @throws IllegalArgumentException if chromosomes array is null or empty
31 */
32 public Genotype(final Chromosome... _chromosomes) {
33 Validate.notNull(_chromosomes);
34 Validate.isTrue(_chromosomes.length > 0);
35
36 this.chromosomes = _chromosomes;
37 }
38
39 /**
40 * Creates a new genotype with chromosomes from the specified collection.
41 *
42 * @param _chromosomes a collection of chromosomes to include in this genotype
43 * @throws IllegalArgumentException if chromosomes collection is null or empty
44 */
45 public Genotype(final Collection<Chromosome> _chromosomes) {
46 Validate.notNull(_chromosomes);
47 Validate.isTrue(_chromosomes.size() > 0);
48
49 final Chromosome[] chromosomesArray = _chromosomes.toArray(new Chromosome[_chromosomes.size()]);
50
51 this.chromosomes = chromosomesArray;
52 }
53
54 /**
55 * Returns the number of chromosomes in this genotype.
56 *
57 * @return the count of chromosomes
58 */
59 public int getSize() {
60 return chromosomes.length;
61 }
62
63 /**
64 * Returns all chromosomes in this genotype.
65 *
66 * @return an array containing all chromosomes
67 */
68 public Chromosome[] getChromosomes() {
69 return chromosomes;
70 }
71
72 /**
73 * Returns the chromosome at the specified index.
74 *
75 * @param index the index of the chromosome to retrieve (0-based)
76 * @return the chromosome at the specified index
77 * @throws IllegalArgumentException if index is negative or greater than or equal to the number of chromosomes
78 */
79 public Chromosome getChromosome(final int index) {
80 Validate.isTrue(index >= 0);
81 Validate.isTrue(index < chromosomes.length);
82
83 return chromosomes[index];
84 }
85
86 /**
87 * Returns the chromosome at the specified index, cast to the specified type.
88 *
89 * @param <T> the expected chromosome type
90 * @param index the index of the chromosome to retrieve (0-based)
91 * @param clazz the class to cast the chromosome to
92 * @return the chromosome at the specified index, cast to the specified type
93 * @throws IllegalArgumentException if index is invalid or clazz is null
94 * @throws ClassCastException if the chromosome cannot be cast to the specified type
95 */
96 public <T extends Chromosome> T getChromosome(final int index, Class<T> clazz) {
97 Validate.isTrue(index >= 0);
98 Validate.isTrue(index < chromosomes.length,
99 "Index (%d) larger than the number of chromosomes (%d)",
100 index,
101 chromosomes.length);
102 Validate.notNull(clazz);
103
104 return clazz.cast(chromosomes[index]);
105 }
106
107 @Override
108 public int hashCode() {
109 final int prime = 31;
110 int result = 1;
111 result = prime * result + Arrays.hashCode(chromosomes);
112 return result;
113 }
114
115 @Override
116 public boolean equals(Object obj) {
117 if (this == obj)
118 return true;
119 if (obj == null)
120 return false;
121 if (getClass() != obj.getClass())
122 return false;
123 Genotype other = (Genotype) obj;
124 if (!Arrays.equals(chromosomes, other.chromosomes))
125 return false;
126 return true;
127 }
128
129 @Override
130 public String toString() {
131 return "Genotype [chromosomes=" + Arrays.toString(chromosomes) + "]";
132 }
133 }