RepeatedMutationPolicyHandler.java

package net.bmahe.genetics4j.core.mutation;

import java.util.Objects;
import java.util.random.RandomGenerator;

import org.apache.commons.lang3.Validate;

import net.bmahe.genetics4j.core.spec.AbstractEAConfiguration;
import net.bmahe.genetics4j.core.spec.AbstractEAExecutionContext;
import net.bmahe.genetics4j.core.spec.mutation.MutationPolicy;
import net.bmahe.genetics4j.core.spec.mutation.RepeatedMutation;

public class RepeatedMutationPolicyHandler<T extends Comparable<T>> implements MutationPolicyHandler<T> {

	private final RandomGenerator randomGenerator;

	public RepeatedMutationPolicyHandler(final RandomGenerator _randomGenerator) {
		this.randomGenerator = Objects.requireNonNull(_randomGenerator);
	}

	@Override
	public boolean canHandle(final MutationPolicyHandlerResolver<T> mutationPolicyHandlerResolver,
			final MutationPolicy mutationPolicy) {
		Objects.requireNonNull(mutationPolicyHandlerResolver);
		Objects.requireNonNull(mutationPolicy);

		if ((mutationPolicy instanceof RepeatedMutation) == false) {
			return false;
		}

		final RepeatedMutation repeatedMutation = (RepeatedMutation) mutationPolicy;
		return mutationPolicyHandlerResolver.canHandle(repeatedMutation.mutationPolicy());
	}

	@Override
	public Mutator createMutator(final AbstractEAExecutionContext<T> eaExecutionContext,
			final AbstractEAConfiguration<T> eaConfiguration,
			final MutationPolicyHandlerResolver<T> mutationPolicyHandlerResolver, final MutationPolicy mutationPolicy) {
		Objects.requireNonNull(eaExecutionContext);
		Objects.requireNonNull(eaConfiguration);
		Objects.requireNonNull(mutationPolicyHandlerResolver);
		Objects.requireNonNull(mutationPolicy);
		Validate.isInstanceOf(RepeatedMutation.class, mutationPolicy);

		final RepeatedMutation repeatedMutation = (RepeatedMutation) mutationPolicy;
		final MutationPolicy childMutationPolicy = repeatedMutation.mutationPolicy();
		final MutationPolicyHandler<T> childMutationPolicyHandler = mutationPolicyHandlerResolver
				.resolve(childMutationPolicy);
		final Mutator childMutator = childMutationPolicyHandler
				.createMutator(eaExecutionContext, eaConfiguration, mutationPolicyHandlerResolver, childMutationPolicy);

		return new RepeatedMutator(randomGenerator, repeatedMutation, childMutator);
	}
}